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 IIEPI *YXH2. 
 ARISTOTLE 
 
 ON THE VITAL PRINCIPLE. 
 
 Crauslateb from % original 
 
 WITH NOTES BY 
 
 CHARLES COLLIER, M.D., F.R.S. 
 
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 AND HONORARY FELLOW OF THE ROYAL COLLEGE OF SURGEONS. 
 
 ira'Aw iSia nev nva TOU AoyncoC <f>ri(rt TTJ? </o;x^S iftidr;, ISia 
 Se TOV erv^i^vovs xal a'Adyou tlvai, piTrrafdfiei'OS eirl mivra KOJ. )//r)Aa- 
 
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 HKovTcipxov Acii/rara Trepi i 
 
 MACMILLAN & CO. 
 
 LONDON: D. NTJTT. 
 
 1855.
 
 PREFACE. 
 
 HAVING, after careful study of this Treatise, been led 
 to the conclusion that Aristotle's object, in its com- 
 position, was to put before the world his own opi- 
 nions as well as those of former and contemporaneous 
 writers upon the Vital Principle, I have been induced 
 to undertake a translation of it, in order to give the 
 general reader the theories, hypotheses, and opinions 
 which prevailed, at that early period of natural and 
 physiological knowledge, upon life and its manifes- 
 tations. The Treatise, indeed, records all the pre- 
 vailing opinions upon living beings and sentient 
 properties, which lie scattered through Aristotle's 
 other physiological writings; and it displays, per- 
 haps more than any other of his works, the extent 
 of his knowledge, and the perspicacity of his intel- 
 lect. Should it, however, be questioned whether a 
 work, composed at a time when the special sciences 
 pertaining to its subject were yet in their infancy, 
 can be now of any value, it might be answered that, 
 irrespective of any positive result, an interest must 
 ever be taken in the investigation, truthfully con- 
 ducted, of nature's operations; and that this, brief 
 
 1G76134
 
 VI PREFACE. 
 
 as it is, comprises many of the dogmata, of an other- 
 wise enlightened age, upon the more abstruse topics 
 of natural philosophy and physiology. 
 
 It is scarcely necessary to observe, that several 
 versions of this Treatise are extant, but as they have 
 been written under an impression that its design is 
 rather psychological than physiological, this misap- 
 prehension has tended to vitiate, or render unintelli- 
 gible what otherwise, as literary productions, might 
 have done justice to the original. Some of the 
 translators, besides, seem to have been but imper- 
 fectly acquainted with physiology, and this want of 
 preliminary knowledge has sometimes led to a mis- 
 apprehension of the text, and sometimes to an inad- 
 equate appreciation of what could be only suggestive. 
 Thus, the causes which have contributed to make 
 the text abstruse, and even in places unintelligible, 
 have concurred in making the translations obscure, 
 and occasionally incomprehensible; for besides in- 
 dications of imperfect anatomical knowledge, the 
 arguments in the Treatise can be regarded but as 
 suggestions, and be elucidated only by reference to 
 the more matured science of modern times. It cannot 
 derogate from what is due to Aristotle, to admit that 
 physiology, in his age, was not only encumbered 
 with the hypotheses of earlier schools, but also 
 dwarfed and distorted by imperfect acquaintance with 
 those systems and organs of the living body, which
 
 PREFACE. Vll 
 
 he perceived, intuitively, to be necessary to a full 
 comprehension of his subject. But although the 
 opinions and conjectures of this Treatise may, from 
 the advanced state of anatomy and physiology, have 
 but little intrinsic value, the method adopted by 
 Aristotle may not be undeserving the attention of 
 those who, with a wider range of special knowledge, 
 are better prepared for the undertaking; unless, 
 indeed, the Vital Principle is to be set down among 
 those final causes, which, lying beyond the human 
 comprehension, are to be admitted as ultimate facts. 
 Although this may be the case, however, some in- 
 terest must be taken in a Treatise which is, not only 
 indicative of Aristotle's style and mode of argument, 
 but pregnant also, by allusion, with collateral infor- 
 mation. 
 
 This version has been made with the inten- 
 tion of rendering it, in so far as the analogies of 
 language would allow, a faithful transcript of the 
 opinions and manner of Aristotle; and notes are 
 added for the elucidation of passages which by no 
 periphrasis could be made intelligible to the general 
 reader. It may be observed that the mind, (6 vovs), 
 although nowhere denned, appears, in this Treatise, 
 to represent the abstract immaterial principle usually 
 attributed to the ^vxn '> f r it alone is excluded from 
 all direct participation in corporeal functions or 
 changes.
 
 Till PREFACE. 
 
 Although the title given to this version embodies, 
 as I believe, Aristotle's idea, yet it is not pretended 
 that the writers cited by him always employed the 
 term i/^xv m h* 8 sense ; or even that he, himself, 
 was always consistent in the use of it. Plato was 
 certainly not engaged upon material agencies or pro- 
 perties in his Phcedo, and in the Timceus, which 
 partakes of a physiological character, and as such 
 has been criticised in this Treatise, the animating 
 motor principle is treated of rather as an abstraction 
 than as the originating and natural cause of life, 
 through all its manifestations. The term Vital 
 Principle, however, has been retained throughout, 
 even where it may seem to be less apposite, as well 
 to avoid the misapprehension which might be occa- 
 sioned by the substitution of another term, (that of 
 soul I mean,) which might then to some appear to 
 be its synonym, as on account of the extreme dif- 
 ficulty of determining the point where the metonymy 
 might, without question, be adopted. 
 
 This Translation is from the Oxford edition, col- 
 lated with that of Trendelenburg ; and this allusion 
 to that eminent scholar affords me the opportunity 
 of acknowledging the assistance which has been 
 derived from his comments upon passages, which 
 require, for elucidation, all the light that can be 
 thrown upon them by tradition and learning.
 
 INTEODUCTION. 
 
 As this treatise may interest some who have 
 never considered the subject for the elucidation of 
 which it was composed, it will be well to offer a 
 summary of that which Aristotle had undertaken to 
 delineate, and to give, at the same time, an epitome 
 of the opinions which, in modern times, have been 
 entertained concerning it. 
 
 It is then that principle, which, inherent in genial 
 matter, establishes functions distinctive of animated 
 beings ; and those functions are nutrition, and, through 
 nutrition, growth or development, within a certain 
 prescribed range, and absorption or rather change 
 wrought by absorption, that is, decay. These two 
 functions constitute, in fact, animated beings, and 
 distinguish them broadly from whatever is inanimate; 
 and as those functions are inherent in the simplest 
 
 1
 
 2 INTRODUCTION. 
 
 forms of being, it is in such that we might expect to 
 find a clue to the nature of that something which, 
 whether entity or mere quality, confers upon living 
 matter its distinctive properties. But whether we 
 examine a seed before development, or watch the 
 rudimental forms of life, that something lies shrouded 
 in matter which, although to appearance inanimate, 
 is yet, through its influence, under genial conditions, 
 capable of developing into a perfect being; and of 
 resisting, for a stated time, the agency of surrounding 
 elements. Thus, growth and development with their 
 antagonisms absorption and decay, effected through 
 the actions of the material framework of living 
 beings, constitute, essentially, life; and the subject 
 of this essay is that something which gives to matter 
 those attributes. The processes, then, of reproduc- 
 tion, growth, and decay, that is, generation, life, and 
 death, are the essential characteristics of living 
 beings, and conferred upon them, as has been said, 
 by that something which is designated Vital Principle. 
 Now, to homogeneous forms and solitary functions 
 others of more complex nature are superadded, and 
 these give rise to that long chain of being of which 
 man may be regarded as the head ; but yet, amid all 
 the simplicity of organs, of action, and of reaction, 
 those two functions still prevail, and constitute life,
 
 INTRODUCTION. 3 
 
 whatever the type of being, in its strictest significa- 
 tion. This is the teaching of Aristotle, as it is the 
 doctrine of modern physiologists ; and those functions 
 are always here referred to as the essential conditions 
 of whatever is animated, although, for higher forms 
 of being, other "organs and functions are required. 
 The nature, however, of the essence or principle 
 which originates and orders those living functions is 
 hitherto for us, as it was for Aristotle, inscrutable ; 
 and it may be that the wide survey which he took of 
 life, by complicating simple functions with sentient 
 and even intellectual faculties, tended only to disturb 
 and pervert the course of his inquiry. But whether 
 Aristotle's mode of inquiry was or not faulty, and 
 whether the principle which animates the world (it 
 may be the universe) is or not among those causes 
 which are inscrutable, it will be ever a topic of deep 
 interest to the learned and the thoughtful of every 
 age. 
 
 In an opening chapter, Aristotle has in so clear 
 and succinct a manner reviewed the prevailing doc- 
 trines and opinions as well of his own as of a pre- 
 ceding age, that that summary may be regarded as 
 the exposition of all that was then most authoritative; 
 and as, from that time, physiology may be said to 
 have declined, it would be almost supererogatory to 
 
 12
 
 4 INTRODUCTION. 
 
 allude to any other writer before the rise of modern 
 science. It may be mentioned, however, in deference 
 to the name, that Cicero 1 has alluded, with a just 
 appreciation of Aristotle's superiority, to this treatise ; 
 but as the topic was foreign to his pursuits and little 
 in accordance with his talents, we cannot be sur- 
 prised if he mistook the scope of the design, and per- 
 verted thereby the tendency of the argument. 
 
 This treatise is, it may be added, both an intro- 
 duction and a sequel to the other physiological trea- 
 tises of Aristotle ; and, as it treats of all the charac- 
 teristics of living beings, it may contribute to a 
 clearer understanding of them, as they, in their turn, 
 may serve to elucidate it ; for they all proceed from 
 the same hand, maintain the same doctrines, and 
 emanate from the same laborious and original 
 intellect. 
 
 This topic engaged the attention of eminent ana- 
 tomists and physiologists towards the opening of the 
 present .century, and their writings will shew the 
 opinions entertained by the moderns concerning it; 
 but it has, generally, been made an incidental rather 
 than a special subject of inquiry, a prelude, aa it 
 were, to the teaching of anatomy and physiology. 
 The opinions entertained concerning vital principle 
 
 1 Tusc. Disp. Lib. I. i.
 
 INTRODUCTION. 5 
 
 by the eminent men here alluded to (Hunter and 
 Barclay, Bichat and Cuvier) may well be collated 
 with those of Aristotle, who wrote at a time when 
 science was in its infancy, and when, for profitable 
 investigation, he had to depend almost exclusively, 
 amid so much hypothesis, upon his own laborious 
 and perspicacious intellect. 
 
 In quoting those writers, there is hardly occasion 
 for observing any order of precedence, as they 
 flourished about the same time, and contributed 
 equally to the present development of physiological 
 science. 
 
 According to Hunter 1 , "Animal matter is en- 
 dowed with a principle called, in common language, 
 life. This principle is perhaps conceived of with 
 more difficulty than any other in nature, which arises 
 from its being more complex in its effects than any 
 other; and it is, therefore, no wonder that it is the 
 least understood. But, although life may appear 
 compounded in its effects in a complicated animal 
 like man, it is as simple in him as in the most simple 
 animal, and is reducible to one simple property in 
 every animal." In another paragraph, he adds, 
 " the first and most simple idea of life is its being 
 the principle of self-preservation, by its preventing 
 
 1 On Vital Principle,
 
 6 INTRODUCTION. 
 
 matter from falling into dissolution for dissolution 
 immediately takes place when matter is deprived of 
 it; the second is its being the principle of action. 
 These are two very different properties, though they 
 arise from the same principle." 
 
 Barclay 1 observes that, " in every living organized 
 structure there is plainly a power that preserves, 
 regulates, and controls the whole ; directing, at first, 
 the different processes in forming one part of the 
 organs, afterwards employing the assistance of the 
 organs which it has formed to produce more, till at 
 last it completes the whole of the system in such a 
 manner as to suit its future conveniences and wants. 
 This power, or rather this agent, physiologists have 
 named Vital Principle; though not a few are inclined 
 to suppose it to be the effect, rather than the cause, 
 of the organization. But in all operations that are 
 performed without either volition or consciousness, it 
 appears subordinate to a much higher power to that 
 Almighty and Omniscient Being, who dispenses his 
 laws to the boundless Universe, and whose laws, ex- 
 cept by himself, can never be improved, altered, or 
 abrogated." 
 
 Bichat 2 makes Vital Principle to be "the assem- 
 blage of the functions which resist death ;" and this 
 
 1 Introduction to Anatomical Nomenclature. 
 
 2 La Vie et la Mort,
 
 INTRODUCTION. 7 
 
 definition was adopted substantively by Cuvier, who, 
 in his introductory lecture to the " Comparative Ana- 
 tomy," has illustrated the influences of this assumed 
 principle, by a : description, alike graphic and beauti- 
 ful, of what takes place when it has been withdrawn 
 or extinguished. "If 1 ," he observes, "in order to 
 have a correct idea of life, we consider it in simple 
 forms of being, we shall soon perceive that it consists 
 in the faculty possessed by particular corporeal com- 
 binations of lasting for a given time and under a 
 determined form; of attracting, incessantly, into their 
 composition a portion of the surrounding substances, 
 and in giving back to the elements portions of their 
 own substance. So long as this series of move- 
 ments is maintained, the body, in which it is mani- 
 fested, is a living body; and when it is irrecoverably 
 arrested it is dead." 
 
 But although the definition of Bichat involves a 
 great truth, and is a summary of all that has been 
 ever said upon the subject, it is open to the criticism 
 of M. Magendie, that, by its admitting the idea of 
 death, it presupposes life, and thus establishes a 
 vicious circle of reasoning. It is criticised also by 
 M. Comte 2 , as a fancied antagonism between animate 
 and inanimate matter, a chimerical struggle between 
 1 Regne Animal. z Science Bwlogique.
 
 8 INTRODUCTION. 
 
 living beings and surrounding influences; for "the 
 idea of life," he observes, "presupposes something 
 able to live, and it requires no less a certain assem- 
 blage of external influences for its fulfilment." 
 
 The nature of Vital Principle, then, is still for us, 
 as it was for Aristotle, a great mystery; and as 
 opinions upon it are at best but speculations, we may 
 proceed, without further comment, to the text, which, 
 besides miscellaneous matter, will be found to contain 
 suggestions for reflexion and inquiry.
 
 PRELUDE TO CHAPTER I. 
 
 THIS chapter is an elaborate statement of the subject as 
 well as the object of the inquiry. The term ^J/VXTJ, 
 here rendered "Vital Principle," has several signi- 
 fications, as was observed in the preface, in the 
 course of this and the other physiological treatises: 
 in one passage, it implies the life of an animal ; in 
 another, the nutritive function ; in another, a vital 
 part; in another, a motor force; and in another, the 
 visual power (rov o^a-ros ; ^v-^tj 1 ) ; some writers, 
 besides, derived the term ^v-^rj from -v^v^/ao? or 
 if/w^oi, coolness or cold, because respiration was held 
 to be a cooling process, and as such essential to life. 
 The object of Aristotle, then, in this treatise, was to 
 learn the nature of that essence or principle which, 
 under whatever denomination, is the innate source 
 of motion, and, consequently, of vital actions in all 
 bodies capable of being animated; for although, in the 
 more complicated forms of being, it is involved in 
 
 1 De Sensu et Sens. II. 16.
 
 10 PKELUDE TO CHAP. I. 
 
 the manifestation of perceptions and passions, its 
 great office still is to originate, to maintain, and to 
 perpetuate life, through all its gradations. It may be 
 that, from some such conclusion, Aristotle was led to 
 regard the vital principle as inferior in destiny and 
 office to the faculty which he has designated 1 mind 
 (o i/ovc), and made to be impassive, homogeneous, 
 apart from, and independent of, the body. These 
 opinions have much in common with those adopted 
 by Plato in the Timaeus; as, while, in that most 
 beautiful and intellectual disquisition, the senses, 
 appetites, and passions, the mortal framework, that 
 is, of the sentient being, are located about the heart 
 and liver, the intellectual faculty, that which is 
 divine, and intended to direct and control the animal 
 powers, is placed in the head. The life is repre- 
 sented, in fact, by ^v^tj, which is bound up with 
 corporeal functions and appetites ; and reason by 
 i/ous, which, if any where, is, "as the divine seed of 
 wisdom," in the brain ; and, being homogeneous, 
 does not depend, for existence, upon the life of the 
 body. These few words will suffice to shew that 
 there is an analogy between the two systems of phy- 
 siology and psychology. 
 
 1 De An. i. 4 ; i. 5 ; in. 4, 6.
 
 BOOK THE FIRST. 
 
 CHAPTER I. 
 
 IT may be assumed that all knowledge is beautiful 
 and estimable ; but as one branch may be more so 
 than another, either because of the exactness which 
 is requisite for its examination, or from its treating of 
 objects more exalted and wonderful than any others, 
 so, on both these accounts, we may reasonably assign 
 the first place to an inquiry into Vital Principle. For 
 the knowledge of it promises to contribute largely to 
 all truth, and most especially to truth in relation to 
 nature, since it is the origin, as it were, of living 
 beings. The object of our inquiry, then, is to study 
 and ascertain its nature and its essence, as well as its 
 accidents, of which some seem to be its own peculiar 
 affections, and some to belong to living beings, as 
 original properties, through it. 
 
 Let us premise, however, that the attempt to attain 
 to any certainty with respect to it is beset with almost 
 insuperable difficulties; for as this has much in
 
 12 ARISTOTLE ON THE [BK. I. 
 
 common with many other inquiries, with every inquiry, 
 I mean, instituted for ascertaining the essence and 
 the thing itself, it might hastily be supposed that, as 
 demonstration is the method for studying particular 
 "bodies in their accidents, there may be some one special 
 method of investigation when our object is to learn 
 what is the essence of a thing, and that that method 
 ought to be sought for on this occasion. If, however, 
 there is no one common method for ascertaining what 
 any thing in itself is, the systematic treatment of 
 our subject is rendered still more difficult; for, in that 
 case, it will be necessary to adopt, for each particular 
 subject, some one particular method. Although it 
 may be manifest, besides, that the inquiry should be 
 by some kind of demonstration, or division, or other 
 method, there will still remain many difficulties and 
 many liabilities to error in fixing upon the principles 
 from which the inquiry should set out; for the princi- 
 ples of different subjects differ, as those of number 
 are not those of plane surfaces. 
 
 It may be well, perhaps, before proceeding fur- 
 ther, to distinguish the "genus" to which Vital Prin- 
 ciple belongs, and determine what it is determine, I 
 mean, whether it is a something and essence, or quan- 
 tity, or quality, or any other of the classified cate- 
 gories; as also, a distinction of no small importance, 
 whether it is among entities in potentiality, or whether 
 rather it is a reality. We have to consider too whether
 
 CH. I.] VITAL PRINCIPLE. 13 
 
 Vital Principle is divisible or without parts, and 
 whether every Vital Principle is or is not the same in 
 kind, and, if not the same, whether the difference is 
 generic or specific ; but they who now are engaged in 
 discussing and exploring Vital Principle seem to give 
 exclusive attention to that of man. We must be on 
 our guard against this, however, so that it may not 
 escape us whether there is but one definition for Vital 
 Principle as for animal, or whether it must be differ- 
 ent for each creature, as for a horse, a dog, or a man. 
 The term animal, besides, taken in an universal 
 sense, is either without meaning, or of very secondary 
 value; and so equally is every other common term 
 which might be predicated of this subject. If, on the 
 other hand, there are not several Vital Principles, but 
 parts only of a single Principle, we have to settle 
 whether we should commence the inquiry with the 
 Principle as a whole, or, contrariwise, with its parts; 
 and, with respect to the parts, it is difficult to deter- 
 mine which of them have been constituted differently 
 from others ; it is difficult also to say whether we 
 should study the parts before their functions, as the 
 mind before thought, or sensibility before sensation ; 
 and so for other faculties and functions. If it be ex- 
 pedient to commence the inquiry with functions, it 
 may be a question whether it would not be better 
 here also to study first their opposites ; as the object 
 of perception before that which perceives, and thought
 
 14 ARISTOTLE ON THE [BK. I. 
 
 before that which thinks. Now, the knowledge of 
 any thing in itself seems to be useful towards a right 
 conception of the causes of the accidents in sub- 
 stances ; as, in mathematics, the knowledge of straight 
 and curve, line and surface, is requisite for perceiving 
 to how many right angles the angles of the triangle 
 are equal. But the knowledge of the accidents con- 
 tributes, largely, in its turn, towards knowing what 
 the thing, essentially, is ; for whenever we may be able, 
 from the appearance of any substance, to recount the 
 whole or the greater number of its accidents, we are 
 then best prepared to say what its essence is. Thus, 
 the essence is the proper beginning for every demon- 
 stration, so that all the definitions, which do not 
 make known, or make it easy to conjecture what 
 may be the accidents of any substance, are to be 
 regarded as dialectic and unprofitable subtleties. 
 
 It is difficult to determine whether all the emo- 
 tions of Vital Principle are common to it and its 
 recipient, or whether some one emotion belongs to it 
 exclusively ; and this is a question, which, although 
 not easily settled, it is necessary to entertain. There 
 is scarcely one of the many emotions which are de- 
 rived from the Vital Principle, (as anger, or courage, 
 desire, or feeling,) in the manifestation of which the 
 Vital Principle can be said to be affected, actively or 
 passively, without the body; the faculty of thought 
 seems to be the peculiar property of the Vital Prin-
 
 CH. I.] VITAL PRINCIPLE. 15 
 
 ciple, but whether thought be imagination of some 
 kind, or never unaccompanied by imagination, still 
 we must admit that it cannot be exercised without the 
 body. If, then, there is any one function or emotion 
 which is peculiar to the Vital Principle, we should 
 admit that it might be isolated from the body; but, if 
 no one belongs to it, exclusively, then we say that it 
 cannot be separate from one. But, just as many acci- 
 dents concur in the quality straightness, in so far as 
 straightness (as, for instance, among others, to touch 
 a brazen sphere at a point, which, were it apart from 
 some kind of body, it could not do), so straightness is 
 inseparable from a body, since it is ever found to- 
 gether with one. In the same way all the emotions 
 of the Vital Principle (such as courage, gentleness, 
 fear, pity, daring, joy, love and hatred,) seem to be 
 manifested together with the body; for the body is 
 affected, simultaneously, by them. As evidence of 
 which, there are times when we are neither excited 
 nor alarmed, although misfortunes may be trying 
 and palpable, while, at other times, when the body is 
 plethoric, or in a state akin to that of anger, we are 
 moved by incidents which are trivial and unim- 
 portant. And what makes this yet more apparent is, 
 that, at times, without the occurrence of aught to 
 occasion alarm, we are thrown into the state of 
 persons under terror; and if this be true, it is clear 
 that all such emotions are material conditions. So
 
 16 ARISTOTLE ON THE [BK. I. 
 
 that the definition of any one of them, as that of 
 anger for example, may be said to be the motion of a 
 body of particular nature, or part or function of a 
 body, by such a cause, and for such an end. 
 
 Thus, for these reasons, it is for the physiologist 
 to study the Vital Principle, either as a whole, or 
 under some particular manifestation. But the phy- 
 siologist and the metaphysician would differ widely 
 in their definition of any one of those emotions, as 
 that of anger, for example ; which, while the latter 
 would hold to be desire for retaliation, or some such 
 motive, the former would maintain to be ebullition of 
 blood, or excess of heat about the heart. The one of 
 these, in fact, accounts for the passion by the matter, 
 and the other by the form and cause ; for the form is 
 the cause of the thing, which, if it is to be, must, of 
 necessity, be in a special matter. Thus, the cause of 
 a house, for instance, is such as this " to be a shelter 
 to avert injury from rain, wind, and heat;" and here 
 the physiologist will speak of stones, bricks, and 
 rafters, while the metaphysician will, in these mate- 
 rials, only behold the form to be adopted for those 
 purposes. Which, then, of these is the physiologist? 
 Is it he who studies only the matter without refer- 
 ence to the cause, or he who is occupied with the 
 cause only? Or is it rather he who judges both from 
 cause and matter ; and which of the two is he ? May 
 we not however rather say that there is one who is
 
 CH. I.] VITAL PRINCIPLE. 17 
 
 engaged upon the properties which are inseparable 
 and only in so far as they are inseparable from matter, 
 while to the physiologist it belongs to judge of such 
 emotions and functions as emanate from particular 
 bodies and peculiar matter ? Properties different from 
 these belong to another ; and some of them to an 
 artisan, a physician or builder, as the case may be, 
 while the mathematician has to do with properties 
 which are not inseparable from matter, but which, as 
 they do not belong to any particular body, admit of 
 being treated as abstractions ; and abstract qualities, 
 as abstractions, belong to the transcendental philo- 
 sopher. 
 
 Let us, however, return to the point where our 
 discussion broke off, and repeat that the emotions of 
 Vital Principle, such as anger and fear, for instance, 
 in so far as they are innate, are inseparable from the 
 material frame-work of animals; and that they are 
 not to be regarded as a line or a surface.
 
 PRELUDE TO CHAPTER II. 
 
 THIS chapter is a review of the opinions of earlier and 
 contemporaneous writers upon the Vital Principle, 
 and as Aristotle has never failed at the outset of each 
 subject of inquiry to record the principal writers upon 
 it, he may be regarded as the founder of tradition in 
 science. The writers here cited may be divided into 
 those who made motion, and those who supposed 
 feeling to be the essential characteristic of that which 
 imparts life to matter ; although there were some 
 who attributed to it both motion and feeling. 
 
 CHAPTER II. 
 
 As we are now entering upon the study of Vital 
 Principle, and are encompassed with doubts which 
 ought to be resolved, it will be incumbent upon us to 
 gather the opinions of such of the earlier writers as 
 have suggested any thing concerning it, in order that 
 we may be able as well to adopt their happier concep- 
 tions as to be on our guard against their errors.
 
 CH. II.] ARISTOTLE ON THE VITAL PRINCIPLE. 19 
 
 The suitable opening for this inquiry into the 
 Vital Principle is to lay down the properties which 
 appear, most especially, to belong to it. The ani- 
 mated being, then, seems to be especially distinguished 
 from whatever is inanimate by the two properties of 
 motion and feeling; and these two are almost the 
 only distinctions which have been transmitted to us 
 by the earlier writers upon the subject. Thus, some 
 of them maintain that the Vital Principle is in the 
 largest, fullest sense a motor power; and as they 
 believed that nothing can impart motion unless it be 
 self-motive, they assumed that the Vital Principle 
 must be among beings which are self-moved. Hence 
 Democritus says that it is a kind of fire and heat, and 
 as forms and atoms are, according to him, infinite, he 
 speaks of those which are spherical and apparent in 
 the sun's beams, while passing through chinks in 
 doors, as fire and Vital Principle ; and further says, 
 that those atoms, collectively, are the elements of 
 universal nature. Leucippus, in like manner, is dis- 
 posed to regard the spherical atoms as Vital Prin- 
 ciple, both on account of those forms being best 
 adapted for penetrating every where, and best able, 
 from being self-motive, to give motion to other things ; 
 and thus they both assume that it is Vital Principle 
 which imparts motion to living beings. Hence, too, 
 they make breathing to be the boundary of life for 
 they maintain that the envelopment of animal bodies 
 
 22
 
 20 ARISTOTLE ON THE [BK. I. 
 
 crushes by its contraction those forms of atoms which, 
 from never being at rest, give motion, and that com- 
 pensation is afforded for their exit by the entrance of 
 other like forms, during inspiration; and that these 
 forms, while entering, resist the contracting and 
 solidifying power, and preclude the expulsion of all 
 the atoms which are essential to life. They further 
 maintain that animals can live only so long as they 
 can support this process. The opinion adopted by 
 the Pythagoreans seems to be to the same purport 
 for some of them have maintained that Vital Principle 
 is the motes in the air, and others that it is that which 
 gives motion to the motes ; and it has thus been said 
 of those corpuscles, because of their appearing to be 
 constantly moving, although the air may be quite 
 still. 
 
 To the same point do they also come who say that 
 the Vital Principle is self-motive ; for all these philo- 
 sophers seem to have assumed that motion is the most 
 characteristic property of the Vital Principle ; and 
 that, while all other things are moved by it, it is self- 
 moved, and the more so, as they do not see any motor 
 which is not self-moved. 
 
 Anaxagoras, in like manner, says that the Vital 
 Principle is a motive force, and the same opinion may 
 be attributed to any one who, with him, may have 
 maintained that the mind has given motion to the 
 universe; and yet his opinion is not altogether in
 
 CH. II.] VITAL PRINCIPLE. 21 
 
 accordance with that of Democritus. Democritus, in 
 fact, maintains that Vital Principle and mind are 
 absolutely identical ; that the apparent is the true ; 
 and that Homer, therefore, has done well in repre- 
 senting Hector as "changing his mind while he lay." 
 Thus he does not employ the term mind as a faculty 
 for the attainment of truth, but makes mind to be 
 identical with the Vital Principle. Anaxagoras is 
 less explicit upon these points ; for, in many places, 
 he speaks of mind as the source of the beautiful and 
 the true, while, elsewhere, he says that it is identical 
 with the Vital Principle, and innate in all creatures, 
 larger or smaller, higher or lower, in the scale of 
 being ; but it is manifest that mind, in the sense of 
 intellect, is not equally allotted to all animals, nor 
 even to all men. 
 
 Thus they who have looked upon living beings 
 with respect to motion, have assumed that the Vital 
 Principle is the most motive of entities, and so many 
 as have looked upon them with respect to knowledge 
 and sentient perception, have said that the Vital 
 Principle comprises all first causes ; of which, while 
 some admit of several, others maintain that there is 
 only this one. Empedocles, for instance, seems to 
 maintain that the Vital Principle is derived from 
 all the elements, and that each element is Vital 
 Principle, as he says that " by earth we perceive 
 earth, by water water, by air air, by fire destructive
 
 22 ARISTOTLE ON THE [BK. I. 
 
 fire, by attraction attraction, and by repulsion dire 
 repulsion." 
 
 Plato, in a like manner, in the Timaeus, derives 
 the Vital Principle from the elements for like, there- 
 in, is known by like, and things are derived from 
 first causes ; and so, likewise, have things been denned 
 by him in the treatises " upon philosophy." Accord- 
 ing to them, animal, in itself, is derived from the 
 abstract idea of unity, and primal length, and breadth, 
 and depth ; and other things in a somewhat similar 
 manner. It is besides maintained, but in a different 
 sense, that the mind is unity, and knowledge duality, 
 although, as one branch, it is unity ; and that the 
 number of the surface is opinion, that of the solid 
 sensation, for numbers were spoken of by him as 
 forms and first causes, and as derivatives from the 
 elements. Thus, some things are discriminated by 
 mind, some by knowledge, some by opinion, and 
 others by sensation ; as the numbers which represent 
 those faculties are the forms of things. 
 
 Since the Vital Principle has to some appeared to 
 be both motive and capable of knowing, there are 
 writers who have combined motion and intelligence, 
 and then represented the Vital Principle as a number 
 endowed with self-motion. 
 
 Philosophers differ with respect to first causes, 
 both as to their nature and number ; but they who 
 make them corporeal differ most from those who hold
 
 CH. II.] VITAL PRINCIPLE. 23 
 
 them to be incorporeal; and from these again they 
 differ who make them to be a combination both of 
 corporeal and incorporeal molecules. They differ 
 also with respect to the number of such causes, as 
 some adopt only one while others admit of several ; 
 and, in accordance with these conclusions, they form 
 their estimate of the Vital Principle ; but yet they 
 have all assumed, and not unreasonably, that it is of 
 the nature of first causes to be motive. Hence, the 
 Vital Principle has to some appeared to be fire, as 
 fire, besides being the most attenuated and most 
 incorporeal of the elements, is both self-motive and 
 a primal cause of motion in other things. 
 
 Democritus has expressed himself more clearly 
 than any other writer in specifying the causes of each 
 of those properties : for he says that the Vital Prin- 
 ciple is identical with the mind, and to be placed 
 among primal and indivisible bodies ; that it is motive, 
 owing to the tenuity of its parts and its form ; that 
 of forms the spherical is the most mobile, and that 
 this is the form both of mind and fire. 
 
 Anaxagoras seems, as we have already said, to 
 distinguish the mind from the Vital Principle, although 
 he employs both terms as if synonymous ; excepting 
 that he sets down the mind as being, in the fullest 
 sense, the origin of all things. Thus he says that the 
 mind alone of all entities is homogeneous, unmixed, 
 and pure ; and to the same principle he attributes
 
 24 ARISTOTLE ON THE [BK. I. 
 
 the properties both of knowing and imparting motion, 
 as he maintains that it is the mind which has given 
 motion to the universe. 
 
 Thales, too, from what has been recorded of him, 
 seems to have assumed that the Vital Principle is 
 something motive, since he said that the loadstone 
 must have a Vital Principle because it gives motion 
 to iron. 
 
 Diogenes, together with some other writers, held 
 the Vital Principle to be air, because air was believed 
 to be the most attenuated of the elements, as well as 
 an originating cause ; and that, through these proper- 
 ties, the vital principle is able both to recognise things 
 and to impart motion to them. They argued that 
 Vital Principle, as being a first cause and the origin 
 of other things, is able to recognise them ; and that, 
 as being the most attenuated of entities, it is motive. 
 
 Heraclitus also maintains that the Vital Principle 
 is a first cause, since, in his system, it is the exhala- 
 tion out of which he constitutes every thing else ; he 
 regards it too as the most incorporeal of entities, and 
 as being "in a constant state of flux;" and further 
 says, that the moved must be known to the motor. 
 He agreed, in fact, with most others in believing all 
 things to be in motion. 
 
 The opinions of Alcmaeon upon the Vital Principle 
 seem to be very like those just cited for he says that 
 it is immortal, on account of its resemblance to the
 
 CH. II.] VITAL PRINCIPLE. 25 
 
 immortals, and that this resemblance is manifested by 
 its being continuously in motion ; for all divine bodies, 
 he argues, the moon, sun, stars, and heavens, are con- 
 tinuously moving. 
 
 Some writers of smaller pretension and Hippo 
 was one of them have ventured to represent the Vital 
 Principle as water ; and they seem to have been led 
 to this persuasion by the nature of semen, which, in 
 all creatures, is fluid. Hippo, indeed, reproves those 
 who assert that the Vital Principle is blood, because 
 blood is not semen ; and semen is, according to him, 
 the first principle of life. 
 
 Others have maintained, as did Critias, that the 
 Vital Principle is blood, from their assuming that 
 the most peculiar property of blood is feeling, and 
 that feeling is imparted to us through the nature of 
 blood. All the elements, in fact, have had their 
 partisans, excepting earth; and no one has adopted 
 it, unless such an opinion may be attributed to those 
 who have derived the Vital Principle from all, or 
 made it to be all the elements. 
 
 Thus, all these philosophers define Vital Principle 
 by the three properties, motion, feeling, and incorpo- 
 reity, each of which is referrible to first causes. Such 
 of them, therefore, as define it by the faculty of 
 knowing, make it to be an element or a derivative 
 from the elements, and, with one exception, their 
 opinions coincide ; for they all maintain that like is
 
 26 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. I. 
 
 known to like, and, since the Vital Principle recog- 
 nises all things, they constitute it out of all first 
 causes. But such as admit of only one cause and 
 one element, set down Vital Principle as being that 
 one, be it fire or air ; and such as admit of several 
 first causes, set down Vital Principle as being multi- 
 ple also. Anaxagoras stands alone in maintaining 
 that mind is impassive and without anything in com- 
 mon with aught else ; but, even were it so, he has 
 not explained, nor is it easy from what he has said to 
 explain, how or for what purpose it is to recognise 
 anything. So many writers as admit contraries 
 among first causes, constitute the Vital Principle 
 out of contraries, and so many as admit only one 
 contrary, whether hot or cold, or other analogous 
 contrast, make the Vital Principle to be that one. 
 Hence, led by the terms, some maintain that Vital 
 Principle is heat, because from heat the term life has 
 been adopted; and others affirm that it is cold, because 
 from cold, through respiration, the term Vital Prin- 
 ciple has been derived. 
 
 Such, then, the opinions which have been trans- 
 mitted to us upon Vital Principle, and such the 
 reasons upon which those opinions have been 
 grounded.
 
 PRELUDE TO CHAPTER III. 
 
 THIS chapter is upon motion, and its purport is to learn 
 whether the Vital Principle is in motion or at rest, 
 and if in motion, whether self-moved or in motion 
 imparted to it ; its object is also to inquire whether 
 motion proceeds directly from Vital Principle, 
 whether, that is, it impels to move while it is itself 
 at rest, or whether it imparts to the body the 
 motions which it first communicates to itself. Aris- 
 totle * admits of the six following modes of motion : 
 generation, corruption, growth, decay, change and 
 locomotion, which are all vital processes ; but as, in 
 a succeeding passage of this chapter, he speaks of 
 only four modes, he may have supposed that the two 
 first are included in the four last. There is an 
 incidental allusion to movement by conveyance, to 
 movement, that is, without progression. The inquiry 
 proceeds to the question whether Vital Principle is 
 self-motive, and, if so, whether it is or not still 
 
 1 Metaphys. ill. 7.
 
 28 ARISTOTLE ON THE [fiK. I. 
 
 subject to motion by impulse from without, which 
 seems to be answered in the negative ; for it can 
 scarcely be admitted that this Principle can be 
 subject to external impulse, since its movements, if it 
 do move, must result from sensual impressions. 
 
 CHAPTER III. 
 
 BEFORE proceeding farther, let us consider the nature 
 of motion ; for it may not only be untrue that Vital 
 Principle is, as some affirm, essentially self-motive or 
 capable of producing motion ; but it may be one of 
 those entities to which motion cannot possibly be- 
 long ; and it lias already been said that the motor is 
 not necessarily itself in motion. 
 
 Everything moved admits of being moved in two 
 ways : either by itself or by something else ; and by 
 something else we mean whatever is moved from 
 being in something which is moving, as sailors for 
 instance, for they are not moved as is the vessel, 
 since it is moved by itself, but they are moved from 
 being in that which is moved. This is clear by 
 reference to their limbs a particular movement of 
 the feet is walking, and walking is man's progression; 
 but the sailors do not at that time move by walking. 
 Since then motion may be spoken of in this two-fold
 
 CH. III.] VITAL PRINCIPLE. 29 
 
 sense, let us consider whether the Vital Principle 
 moves by itself, and whether it partakes also of 
 motion communicated to it. As there are four kinds 
 of movement, tram I ition, change, growth, decay, it 
 follows that the Vital Principle should move accord- 
 ing to one, or more than one, or all of them ; and 
 if it do not move by chance, then motion must be 
 natural to it; and if so, then locality, for all the 
 movements above alluded to are local. 
 
 But if Vital Principle be essentially self-motive, 
 then accidental movement will not belong to it as to 
 a white colour or a length of three cubits ; for these 
 properties do move, but then it is by accident, and 
 owing to the bodies to which they belong happening 
 to be in motion. Thus, there cannot be for them any 
 locality as there will be for the Vital Principle, if it 
 partakes of motion by its own nature. Although, 
 however, it may be in motion by its own nature, it 
 may still be moved by force, and if by force, still by 
 nature; and the same holds good for the state of 
 rest. Thus, the point towards which anything is by 
 its nature moved, serves also by nature for its point 
 of rest, as equally the point to which anything is 
 moved by force serves also, by force, for its point of rest. 
 It is not easy, however, even conjecturally to deter- 
 mine what will be the forced movements and forced 
 states of rest of the Vital Principle if its motion be 
 upwards it will be fire, if downwards, earth, for such
 
 30 ARISTOTLE ON THE [BK. I. 
 
 are the tendencies of those elements ; and this conclu- 
 sion applies equally to the intermediate movements. 
 Since the Vital Principle besides appears to give 
 motion to the body, it is probable that it communi- 
 cates to the body the motions which it imparts to 
 itself, and, if so, the converse may be true that it 
 communicates to itself the motions which it imparts 
 to the body. Now, the body is moved by translation, 
 so that the Vital Principle should change with the 
 body and be set free from it, either wholly or in its 
 parts ; and if this is admitted, it should follow that 
 the Vital Principle, having gone forth from the body, 
 might re-enter, and the consequence of this would be 
 that the dead bodies of animals rise again. . Could 
 the Vital Principle be subject to casual motion com- 
 municated by some other power than its own, then 
 an animal might be impelled to move by impulse 
 from without; but it is noway necessary that that 
 which is essentially self-motive should be moved by 
 something else, unless by mere chance, any more 
 than that which is good, in and for itself, should be 
 so by or for the sake of something else. It may be 
 confidently affirmed besides, that the Vital Principle, 
 if it do move, is moved by objects which act upon 
 the senses. Although, however, Vital Principle 
 should be self-motive, it would still be in motion, 
 and thus, as all motion is displacement of that which 
 moved, as being moved, the Vital Principle might
 
 CH. III.] VITAL PRINCIPLE. 31 
 
 be displaced from its essence, unless its self-motion 
 were a casual property ; but self-motion is of its very 
 essence. 
 
 Some philosophers maintain that the Vital Prin- 
 ciple moves the body in which it is, as it is itself 
 moving, and this is the opinion of Democritus, who 
 expresses himself almost in the words of the comic 
 poet Philippus, who charges " Daedalus with having 
 made a wooden Venus to become movable, when 
 quicksilver was poured into it." Democritus, in feet, 
 says much the same thing when he maintains that 
 indivisible spheres are in motion, from their having 
 been by nature constituted never to remain at rest, 
 and that these spheres drag along with them and give 
 motion to all things. But we will ask Democritus 
 whether it is those self-same spheres which produce 
 the state of rest, and it will be difficult or rather im- 
 possible for him to explain how they are to do so. It 
 is not thus, besides, that the Vital Principle appears 
 to give motion to an animal, as it acts, generally 
 speaking, by some kind of election and thought. 
 
 It is in this same manner, however, that Timseus 
 physiologically explains how the body is moved by 
 the Vital Principle that, from its being in motion, 
 the body, with which it has been interwoven, is 
 moved also ; and having constituted it out of the ele- 
 ments, and divided it according to harmonic numbers, 
 in order that it may have an innate sense of harmony,
 
 32 ARISTOTLE ON THE [BK. I. 
 
 and that the universe may move in accordant orbits, 
 he bent the straight line into a circle, and dividing 
 that circle into two united in two parts, he again di- 
 vided the single circle into seven others, as if to indi- 
 cate that the orbits of the sky are the movements of 
 the Vital Principle. 
 
 But, in the first place, it is not correct to say that 
 the Vital Principle is magnitude, for Timaeus evi- 
 dently means that this Principle of the universe is 
 such as is the so-called mind ; and, then, that Principle 
 of the universe can resemble neither the sentient nor 
 the concupiscent faculty, as neither of these moves in 
 a circle. The mind is one and continuous as is cogi- 
 tation, and cogitation as are thoughts, and thoughts are, 
 by concatenation, one, in the sense, not of magnitude, 
 but of number ; and, therefore, the mind is not con- 
 tinuous in the sense of magnitude, but either it is 
 without parts, or, at all events, not continuous as 
 magnitude. How, indeed, were it magnitude, is it to 
 think as a whole, or by some one of its parts ? But 
 parts must be regarded either as magnitude, or as 
 points, if, indeed, a point may be regarded as a part; 
 and, if parts be considered as points, then, as points 
 are innumerable, the mind, clearly, will never be able 
 to recount them all, and if, as magnitude, the mind 
 will have to dwell very often, or rather continuously, 
 upon the same subject. But it is manifest that think- 
 ing may be exercised once for all. If, besides, it
 
 GH. III.] VITAL PRINCIPLE. 33 
 
 suffice for thinking, that there should be contact by 
 some one of its parts, why should it move in a circle, 
 or why be magnitude? And if necessary for thinking 
 that there should be contact by the whole circle, then 
 what means contact by its parts? How, besides, 
 shall that which has parts think by that which is 
 without parts, or that which is without by that which 
 has parts ? Thus, it follows that the mind must be 
 that circle: for thinking is the movement of the mind, 
 as the periphery is the movement of the circle ; and, 
 if thinking be the periphery of the mind, the mind 
 may be regarded as the circle, of which thinking is 
 the periphery. But then the mind will be ever 
 thinking, and necessarily so, since the peripheral 
 movement is unceasing. Now, there are limits to 
 practical thoughts, (as all such are for the sake of 
 something else,) and so equally there are to specu- 
 lative thoughts, in their reasons ; and every reason is 
 either a definition or a demonstration. Thus, demon- 
 strations set out from a principle, and are, in some 
 way, terminated by a syllogism or a conclusion; and 
 even though not concluded, they do not revert to 
 their principle, but, taking up another mean and ex- 
 treme, they proceed on ward ; but the periphery, on 
 the contrary, does revert to its point of departure. 
 Definitions, however, are always limited. If, more- 
 over, the same periphery recur often, the mind will 
 be driven to think often upon the same subject, and 
 
 3
 
 34 ARISTOTLE ON THE [BK. I. 
 
 thinking, besides, seems rather to be a kind of rest 
 and a halt than motion ; and this applies equally to 
 the syllogism. As every condition, besides, which is 
 compulsory and ungenial must be unhappy, so unless 
 movement be an essential property of that mind, it 
 must be moving against its nature, and it cannot but 
 be painful for it to have been so connected with the 
 body as to be unable to free itself from it; nay more, 
 it is a lot to have been avoided, since it is better for 
 the mind, as is commonly said, and to many seems 
 reasonable, not to have been connected with a body 
 at all. The cause too, of the circular movement of 
 the sky is obscurely stated for the essence of the 
 Vital Principle is not the cause of that movement, as 
 it never does, excepting it be by chance, so move, nor 
 can the body be the cause, as it is the Vital Principle 
 rather which gives motion to it; neither is it ex- 
 plained how it is better for the Vital Principle to be 
 so circumstanced, and yet it ought to have been 
 shewn that God had caused it to have a circular 
 movement, as better for it to be in motion than at 
 rest, and to move in that rather than in any other 
 direction. But as this is an inquiry which belongs 
 rather to other studies, it may, for the present, be laid 
 aside. 
 
 The same incongruity which occurs in most of 
 the theories upon Vital Principle is met with here, in 
 that writers join Vital Principle to and place it in a
 
 CH. III.] VITAL PRINCIPLE. 35 
 
 body without having first settled for what purpose the 
 body is to receive it, or how it is fitted for the office. 
 It would seem, however, to be necessary that this 
 should be settled, as it is through this connexion that 
 the one acts and the other is acted upon, that the one 
 moves and the other is moved ; and these are relations 
 which cannot be attributed to casual associations. 
 There are writers who content themselves with saying 
 what Vital Principle is, without determining any 
 thing about the body its recipient, as if it were ad- 
 missible, according to Pythagorean legends, that any 
 kind of Vital Principle might clothe itself with any 
 kind of body; but every thing, on the contrary, seems 
 to have its own particular character and form. Such 
 opinions are, in fact, very much like maintaining that 
 the builder's art may be undertaken with musical in- 
 struments; but we affirm that as each art must employ 
 its own instruments, so each Vital Principle must 
 employ its own body. 
 
 32
 
 PRELUDE TO CHAPTER IV. 
 
 THIS chapter opens with a definition of harmony, and 
 proceeds to shew that the then prevailing opinion 
 concerning the Vital Principle, as related to har- 
 mony, is not maintainable ; it is not quite agreed 
 upon whether the popular disquisitions here alluded 
 to are Aristotle's commentary upon the Phsedo ; or 
 his dialogue of Endemus ; or a digest of his own 
 oral teachings. The words in the original (\6yov<: 2' 
 oto-rrep evQvvas, K.T.X.), which are rendered " found to 
 be wanting" (Gallice, dont nous avons deja fait justice), 
 signify strictly the scrutiny or passing of the accounts 
 of magistrates at the close of their period of service, 
 and while the result was yet on the balance ; but, to 
 judge by the context, they seem here to imply rather 
 an unfavourable issue, and this is the purport of 
 other versions " alia qusedam opinio de anima 
 tradita reprobata tamen, et his rationibus quae in 
 communisms sermonibus fiunt" The chapter closes 
 with a confutation of the opinion of Xenocrates, that 
 the Vital Principle is a number with self-motion.
 
 CHAPTER IV. 
 
 ANOTHER opinion upon the Vital Principle has been 
 handed down, which to many is not less acceptable 
 than any one of those already alluded to, but which, 
 having been scrutinized in our popular disquisitions, 
 has been found to be wanting. The supporters of 
 this opinion say, that the Vital Principle is some kind 
 of harmony ; that harmony is a mixture and compound 
 of contraries, and that the body is constituted of con- 
 traries. But although harmony is a certain propor- 
 tion or compound of particles mixed together, it is not 
 possible that the Vital Principle should be the one or 
 the other ; for it forms no part of harmony to produce 
 motion, but all writers agree in assigning motive 
 power to the Vital Principle as its most characteristic 
 property. The term harmony, besides, is applicable 
 rather to health and the corporeal powers in general, 
 than to the Vital Principle, as would be very manifest 
 to any one who should undertake to account, by any 
 harmony, for the emotions and functions of the Vital 
 Principle ; for it would be scarcely possible to recon- 
 cile them to one another. If harmony, besides, may
 
 38 ARISTOTLE ON THE [BK. I. 
 
 be spoken of with reference to two points as appli- 
 cable, most especially, to the composition of particles 
 in masses which have motion and proportion, when- 
 ever they may so coalesce as not to admit of any 
 which are homogeneous, and then as applicable to the 
 proportion of the commingled particles, yet in neither 
 sense can it be reasonable to regard Vital Principle as 
 harmony, nor can the Vital Principle be the compo- 
 sition of the parts of the body : for the composition of 
 the parts (and many and various are the compositions 
 of the parts) is quite open to examination but of 
 what can we suppose that the mind, or the sentient, 
 or the appetitive faculty is a composition ? or how is 
 any one of them to be composed ? It is equally 
 absurd to think that the Vital Principle can be the 
 proportion of the mixture, since the mixture of the 
 elements which forms flesh is differently proportioned 
 from that which forms bone. It will happen, too, 
 from this theory, that there are many Vital Principles, 
 and many in every body, if all bodies are from the 
 elements in combination, and if the proportion of the 
 combination is harmony and Vital Principle. We 
 might inquire too of Empedocles, who maintains that 
 each of those bodies exists in a certain proportion, 
 whether Vital Principle is the proportion ? or whether 
 rather is it present in the members, as something 
 different from proportion? Is affinity, besides, the 
 cause of a fortuitous or a definite combination of
 
 CH. IV.] VITAL PRINCIPLE. 39 
 
 parts ? And then, again, is affinity the proportion, 
 or something besides the proportion ? 
 
 Such are the difficulties which present themselves; 
 but if the Vital Principle is something different from 
 the composition, what is that which is simultaneously 
 destroyed with the life, in the flesh, and other parts 
 of an animal ? Besides these questions, since each of 
 the parts of the body has not Vital Principle, unless 
 the Vital Principle is the proportion of the composi- 
 tion in the parts, what is that which is destroyed 
 when the Vital Principle has forsaken the body? It 
 is then clear, from what has been adduced, that Vital 
 Principle can neither be any kind of harmony, nor be 
 moving in a circle. 
 
 But to maintain that the Vital Principle is moved 
 by accident is to maintain, as we have said, that it 
 moves itself as it is moved in that in which it is, and 
 which is moved by it; and that it cannot possibly 
 have locomotion in any other way. It might, how- 
 ever, with greater probability be doubted, and for the 
 following considerations, whether it moves at all 
 for we are accustomed to say that the Vital Principle 
 is daring or afraid, is angry too, and both feels and 
 thinks, and as all these seem to be motions, it might 
 be supposed that the Vital Principle does move. But 
 yet this is no necessary consequence for if to grieve, 
 to rejoice or think are motions, in the fullest sense, 
 then each of them is motion, and motion may be said
 
 40 ARISTOTLE ON THE [BK. I. 
 
 to emanate from the Vital Principle, as anger or fear 
 is produced by the heart being moved in this or that 
 manner, and thinking may be some analogous or 
 different kind of motion ; but some of these phseno- 
 mena are produced by the displacement of certain 
 particles in motion, and others by change, the expla- 
 nation of the quality and manner of which is foreign 
 to the present inquiry. 
 
 Now to maintain that the Vital Principle is angry 
 is very much like saying that it weaves or builds, and 
 thus it would, perhaps, be better to say, not that 
 Vital Principle pities, learns or thinks, but that the 
 man, by his Vital Principle, is so affected or so 
 engaged. It is not, however, hereby implied that 
 motion is in the Vital Principle, but, on the contrary, 
 that sometimes it proceeds to, and sometimes comes 
 from it; as sentient impression is from external objects, 
 and recollection comes from it to the movements or 
 impressions abiding in the sentient organs. The 
 mind seems to be a peculiar innate essence, and to be 
 indestructible ; were it destructible, however, it would, 
 in an especial sense, be so by the dulness attendant 
 upon age, when probably that happens to the mind 
 which takes place in the sentient organs ; for if an 
 aged person could take an eye of a certain character, 
 he would see as well as a young man. Thus, the 
 infirmities of age are attributable, not to the Vital 
 Principle having been in aught affected, but to its
 
 CH. IV.] VITAL PRINCIPLE. 41 
 
 recipient suffering, as it does from drunkenness or 
 maladies. Thus, too, thought and reflexion languish 
 when any thing within the body has been destroyed, 
 but that which thinks is impassive. The properties-, 
 therefore, of thought, love and hatred belong, not to 
 it, but to that which contains it, and as it contains it; 
 so that when this recipient is destroyed, it can neither 
 recollect nor love, as those emotions emanate not from 
 it, but from that which was in common with it, and 
 which has perished. But the mind is probably some- 
 thing more divine, and it is impassive. 
 
 It is, then, manifest from what has been adduced, 
 that Vital Principle cannot be in motion; and if 
 altogether without motion, it cannot clearly be self- 
 moved. 
 
 The most unreasonable by far of all the opinions 
 upon Vital Principle is that which holds it to be a 
 number with self-motion, for it is beset with insuper- 
 able objections ; those, in the first place, which result 
 from the idea of motion, and then those more particu- 
 lar objections to speaking of it as a number. How, 
 indeed, is it possible to think of an unit in motion ? 
 by what or how, being indivisible and homogeneous, 
 is it to be moved? If said to be both motor and 
 moved, it must have distinction of some kind. Since, 
 besides, they say that a line in motion forms a sur- 
 face, and a point in line, then units in motion will 
 form lines, as the point is distinguished from the unit
 
 42 ARISTOTLE ON THE [BK. I. 
 
 only by position; and thus the number of Vital Prin- 
 ciple has already locality and position. If, again, 
 from any number there be subtracted a number or an 
 unit, there remains a different number; but plants 
 and many creatures, after having been divided, live 
 on, and appear still, in a specific sense, to possess the 
 same Vital Principle. It might also be supposed to 
 make no difference whether we speak of the Vital 
 Principle as formed of units or corpuscles ; for if 
 points are substituted for the spherules of Democritus 
 and quantity alone remains, there will still be in that 
 quantity, as in all continuity, a motor and a moved ; 
 for the theory takes account neither of greatness or 
 smallness, but only of quantity. Thus, there must of 
 necessity be something to impart motion to the units. 
 But if the Vital Principle is the motor in an animal, 
 so must it be in the number, and thus the Vital 
 Principle, being no longer motor and moved, is the 
 motor only. Even admitting that the Vital Prin- 
 ciple may, in some way, be an unit, there must still 
 be some distinction between it and other units ; 
 but what distinction, save that of position, can 
 there be between one unit and another? If then 
 the units and points which are in the body are dif- 
 ferent, the units will be on the same spot as the 
 points, for the unit will occupy the place of the point; 
 but what then is there to prevent them from being 
 infinite in number on the same spot, even if there be
 
 CH. IV.] VITAL PRINCIPLE. 43 
 
 only two, as things are indivisible of which the 
 locality is indivisible ? But if the points in the body 
 are the number of the Vital Principle, or if the number 
 formed from the points in the body is the Vital Prin- 
 ciple, why have not all bodies Vital Principle ? Now 
 there seem to be points in all bodies, and those infi- 
 nite in number. How besides is it possible for the 
 Vital Principles to be separated and set free from 
 bodies, since lines are not divisible into points ?
 
 PRELUDE TO CHAPTER V. 
 
 THE argument against the opinion of Xenocrates that 
 the Vital Principle is "a number with self-motion" 
 is continued, and Aristotle, having already objected 
 to it as number, proceeds here, after a brief allusion 
 to what had been advanced, to object to it as being 
 motive. If the Yital Principle be some kind of body, 
 then however attenuated its parts, there must be two 
 bodies in one ; if it be a number, then as the unit is 
 a point, unless that number be innate and peculiar, 
 every kind of body must have Vital Principle, and 
 this cannot be admitted. With respect to its motion, 
 it had been shewn that the unit, being homogeneous, 
 that is without parts, cannot be so acted upon as to 
 move ; if it be motor and moved, it must, as entity, 
 have some distinction, and then it is no longer to be 
 regarded as an unit. The resemblance between this 
 theory and that of Democritus is again alluded to, as 
 the same objection is applicable to both ; for it mat- 
 ters not whether the motor be a monad, or point, or
 
 PRELUDE TO CHAP. V. 45 
 
 corpuscle in motion, since their motion is the cause of 
 motion in other things ; thus, both systems maintain 
 a blind force, and ignore the influences of sensibility 
 and will. It will probably be said that the topic has 
 been too long dwelt upon, but it should be recollected 
 what an important part was assigned by the Pytha- 
 goreans 1 to number, which they derived from the 
 monad or unit, and regarded as the origin, the mat- 
 ter, and the essential properties of beings, and as con- 
 stitutive of the heavens. It has already been said 
 how, as numbers were the first entities in nature, 
 they perceived resemblances to beings and qualities 
 in them rather than in the elements fire, <fec. ; and 
 hence made one combination to be justice, another 
 mind, and so on. 
 
 1 Metapkys. I. 4, 5.
 
 CHAPTER V. 
 
 THE peculiar incongruity to which we have alluded, 
 belongs as well to those who suppose Vital Principle 
 to be some kind of "body with tenuity of parts, as it 
 does to those who with Democritus maintain that the 
 body is moved by the Vital Principle; for if the 
 Vital Principle is in the whole sentient body, then, 
 being some kind of body, there must necessarily be 
 two bodies in one and the same body. And it may 
 be objected to those who speak of it as a number, 
 that if so, there must be many points in a single point, 
 or every kind of body must have Vital Principle, 
 unless it is a number innate and different as well from 
 other numbers, as from the points which are in the 
 body. It results too from this theory, that an animal 
 is moved by a number much in the same way that 
 Democritus, as we have said, gives motion to it ; for 
 what matters it whether we speak of spherules, or 
 large units, or units simply in motion? In either 
 case, the animal is compelled to move from their being 
 in motion.
 
 CH. V.] ARISTOTLE ON THE VITAL PRINCIPLE. 47 
 
 Such and many other such objections may be 
 urged against those who represent Vital Principle as 
 an intimate combination of motion and number ; as it 
 is not only impossible therefrom to give any definition 
 of Vital Principle, but we affirm that it cannot even 
 account for one of its accidents. And this would be 
 evident to any one who should attempt, by this 
 theory, to explain the affections and functions of the 
 Vital Principle, its reasonings, sensations, pleasures, 
 pains, and other such manifestations ; for it would be 
 difficult, as we have already said, to form even a 
 conjecture concerning them from it. 
 
 Now three modes of defining Vital Principle have 
 been transmitted to us : some have represented it as 
 the most mobile of entities from being self-motive ; 
 some as the most attenuated, and others again as the 
 most incorporeal of entities; but we have already 
 reviewed those opinions, and shewn how very ques- 
 tionable and contradictory they are. There remains 
 for us then only to consider in what sense Vital 
 Principle can be said to be derived from the elements. 
 This opinion has been adopted in order to explain 
 how the Vital Principle can perceive and recognise 
 all beings and things; but it necessarily involves 
 many and weighty objections. The supporters of 
 this opinion lay it down as a fact that like recognises 
 like, which is very much like assuming that Vital 
 Principle is, in some way, the things themselves ;
 
 48 ARISTOTLE ON THE [BK. I. 
 
 but things are never homogeneous, as they contain 
 many other particles besides their own; and many or 
 rather infinite in number are their mutual combina- 
 tions. Thus even if it be conceded that the Vital 
 Principle may recognise and perceive the elements of 
 which anything is constituted, by what is it to per- 
 ceive or recognise the thing as a whole, whether it 
 be a man, or flesh or bone ? The same question may 
 be put for any other compound body ; as the elements, 
 constitutive of every such body unite, not in any 
 fortuitous manner, but in a certain proportion and 
 combination, just as Empedocles expresses himself 
 with respect to bone " The bounteous earth, in her 
 vast furnaces, out of eight parts has had allotted to 
 her two of liquid light, of fire four, and bones were 
 made white." It would be to no purpose then, that the 
 elements should be in Vital Principle, unless propor- 
 tion and combination were there also ; for although 
 each element may recognise its like, there will still 
 be nothing whereby to recognise a bone or a man, 
 unless such things be present with it also. But it is 
 scarcely necessary to say that this cannot be; for 
 who can have a doubt whether a stone or a man is 
 or is not present in Vital Principle ? or good or ill, 
 or any other quality? As the term being, besides, 
 admits of several significations (for it signifies some- 
 times a particular object, sometimes quantity or quality, 
 or other one of the specified categories), shall it or
 
 CH. V.] VITAL PRINCIPLE. 49 
 
 not be said that Vital Principle is derived from them 
 all ? Now, there do not appear to be any elements 
 which are common to all the categories. Shall it 
 then be formed only from such elements as pertain to 
 the essence? How, in that case, is it to recognise 
 each of the others? Shall it be said that there 
 are, for each genus, elements and peculiar principles 
 wherewith the Vital Principle may be formed? If 
 so, it will be quantity, and quality and essence; 
 but it is impossible that from the elements of 
 quantity there should be eliminated essence without 
 quantity. 
 
 Such and other such difficulties concur to oppose 
 the opinion of those who say that the Vital Principle 
 is formed from all the elements. 
 
 It is absurd to maintain that like is unimpression- 
 able by like, and yet assert that like is able to perceive 
 and recognise like by like ; and the more so, as these 
 writers set down feeling as they do thinking and 
 recognising, as some kind of impression and motion. 
 But to shew how many doubts and difficulties beset 
 the opinion adopted by Empedocles, that "objects 
 are recognised by the corporeal elements in the rela- 
 tion of like;" we have only to observe that all 
 those parts in animal bodies, which are simply of 
 earth, as bones, sinews and hairs, seem to be alto- 
 gether without feeling, and consequently without any 
 feeling of UJce, and yet, according to the theory, they 
 
 4
 
 50 ARISTOTLE ON THE [BK. I. 
 
 ought to be perceptive. There will be a larger amount 
 of unconsciousness than perception, besides, allotted 
 to each principle, as each will recognise its own 
 individuals, but be unconscious of the many others 
 all the others, in fact, which are unlike. It follows, 
 too, from this theory, that the god must be the most 
 senseless of beings, as he alone cannot recognise the 
 element " repulsion," of which all mortal beings can- 
 not but be conscious, since each of them is derived 
 from all the elements. 
 
 But wherefore, let us ask, have not all beings a 
 Vital Principle, since every thing is either an ele- 
 ment, or derived from one or from more than one, or 
 from all the elements ? Thus, it is necessary to every 
 being that it should recognise some one thing, or 
 more than one, or all things. But we are at a loss 
 to know what that is which individualizes things: 
 the elements are like matter; but that, whatever it be 
 which binds the others together, must of all be the 
 most influential. Now, it is scarcely possible that 
 any thing should be more influential and dominant 
 than the Vital Principle, and quite impossible that 
 any thing should be more so than the mind; for it 
 is probable that the mind was the first-born and 
 sovereign in nature, while these philosophers main- 
 tain that the elements were the first of entities. 
 
 None of these philosophers, however, neither they 
 who maintain that the Vital Principle is derived from
 
 CH. V.] VITAL PRINCIPLE. 51 
 
 the elements, on account of its recognising and per- 
 ceiving things, nor they who regard it as the most 
 motive of beings, can be said to speak of every Vital 
 Principle ; for all sentient creatures are not motive, 
 as there are animals which appear to be fixed abid- 
 ingly to the same spot, and yet locomotion seems, 
 according to these philosophers, to be the only motion 
 imparted to animals by the Vital Principle. They, 
 too, equally err who form mind and sensibility out of 
 the elements for plants appear to be alive, without 
 partaking either of locomotion or sensibility; and 
 many animals have no understanding. But even if 
 we may pass over these objections, and admit that 
 the mind as well as the sensibility may be a part of 
 the Vital Principle, still no general theory could be 
 framed for every Vital Principle, or for it as a whole, 
 or for it individually. Thus, the reasoning in the 
 so-called Orphic verses has been stamped with this 
 same error, for the poet says that " the Vital Prin- 
 ciple, borne by the winds, enters from the universe 
 into animals during respiration." But this cannot 
 possibly be applicable to plants or to some animals, 
 since there are some which do not breathe. This 
 fact, however, had escaped the attention of those who 
 first adopted the hypothesis. 
 
 But even if it be well to form the Vital Principle 
 out of the elements, it by no means follows that it 
 should be out of them all, as one or other part of the 
 
 42
 
 52 ARISTOTLE ON THE [BK. I. 
 
 contraries is able to judge both itself and its oppo- 
 site. Thus, by the straight we know both the 
 straight and the curve, as the ruler is the judge of 
 both, while the curve is the judge neither of itself 
 nor the straight. 
 
 There are writers who maintain that the Vital Prin- 
 ciple has been diffused through the universe, whence 
 probably Thales was led to think that all things are 
 full of gods. But the opinion is not without its diffi- 
 culties. Why, it may be asked, does not the Vital 
 Principle, when in the air .or fire, form an animal 
 rather than when in the elements in combination, 
 although seemingly more generally situated in either 
 of those elements alone ? It might also be inquired 
 why the Vital Principle, which is in the air, is more 
 exalted and more enduring than that which is in 
 animals. On either side, in fact, we are met by 
 absurdity and contradiction ; for it is very unreason- 
 able to speak of air and fire as animals, and absurd 
 to say that they are not so when Vital Principle is 
 conceded to them. Those philosophers, in fact, seem 
 to have assumed that Vital Principle is in those 
 elements, because the whole ought to be specifically 
 as its parts ; and so it was forced upon them to admit 
 that Vital Principle must be, specifically, the same as 
 its parts, if creatures become living creatures by 
 taking in something from that which surrounds them. 
 But if the air, however subdivided, is still homogeneous,
 
 CH. V.] VITAL PRINCIPLE. 53 
 
 and the Vital Principle heterogeneous, it is clear that 
 some one of its parts will, and some other will not be, 
 in the air ; and thus either the Vital Principle must 
 be homogeneous, or else it cannot be present in every 
 part of the universe. It is manifest, then, from what 
 has been adduced, that the faculty of recognising does 
 not belong to Vital Principle by virtue of its being 
 derived from the elements ; as also that it cannot with 
 accuracy or truth be said to be self-motive. 
 
 Since the faculties of knowing, feeling and think- 
 ing, together with desiring, willing and the appetites 
 generally, as also locomotion, growth, maturity and 
 decay, are properties of the Vital Principle, let us 
 inquire whether or not each of those properties is 
 imparted to us by the Vital Principle as a whole 
 that is, does each of those faculties emanate from the 
 Vital Principle as a whole ? do we think, feel, act and 
 suffer by it as a whole, or are different offices assigned 
 to different parts ? Is life in one, or more than one, 
 or in all the parts, or is there some other cause for 
 life than the Vital Principle ? 
 
 Some writers maintain that Vital Principle is 
 divisible, and that by one part it thinks, and by 
 another feels desire ; but what then, if it be naturally 
 divisible, holds its parts together? Not the body 
 certainly, we answer ; for the Vital Principle, on the 
 contrary, appears to hold it together, as from the 
 moment of its departure the body expires and decays.
 
 54 ARISTOTLE ON THE [BK. T. 
 
 If there be a something which makes it one, that 
 something is, in the strictest sense, Vital Principle ; 
 and it will be necessary again to inquire whether that 
 something is indivisible or with parts ; if it be indi- 
 visible, then why not at once conclude that it must 
 be Vital Principle? If it be divisible, reason will 
 again seek to learn what that is which holds its parts 
 together ; and thus may the inquiry be continued in- 
 terminably. With respect to the parts of the Vital 
 Principle, it is difficult to determine what is the part 
 which has been assigned to each of them in the body ; 
 for if it is the whole Vital Principle which sustains 
 the whole body, it is probable that each of its parts 
 sustains some one part of the body. But this is very 
 like an impossibility; for it would be difficult even to 
 conjecture what part the mind could connect with 
 others, or in what way it could do so at all. Thus, 
 plants, when divided, appear to live, and so do some 
 species of insects, as if possessing still the same Vital 
 Principle in a specific, although not in a numerical 
 sense; for each of the parts has sensation and loco- 
 motion for a time, and there is no room for surprise 
 at their not continuing to manifest those properties, 
 seeing that they are without the organs necessary for 
 the preservation of their nature. Nevertheless, in 
 each of those parts coexist all parts of the Vital Prin- 
 ciple, and those parts are, specifically, the same with 
 each other, and with the whole with each other, as
 
 CH. V.] VITAL PRINCIPLE. 55 
 
 being inseparable, and with the whole as being sepa- 
 rable. But the living principle in plants seems to be 
 a kind of Vital Principle, for animals and plants 
 alike partake of it ; and it is separable from the sen- 
 tient principle, but yet without it no creature can 
 possess sensibility.
 
 PRELUDE TO CHAPTER I. 
 
 AFTER haying delineated his subject and quoted and com- 
 mented on the leading opinions concerning it, Aris- 
 totle here reverts to the definition of Vital Principle, 
 which was given partially at the commencement of 
 the inquiry, with the intent of giving to it a signifi- 
 cation comprehensive enough to include all living 
 beings ; for he had guarded us against limiting the 
 inquiry to the human family. The argument com- 
 mences as usual with Aristotle, ab ovo, he attempts, 
 that is, to fix the meaning of essence, matter and 
 form, those primordial entities or conditions, which 
 make up and serve to distinguish all the beings and 
 things of the external world. These very abstruse 
 questions have been alluded to in a former note, and 
 passages were then cited from the Metaphysics and 
 other works for the purpose of obtaining, if possible, 
 precise notions concerning them ; but these abstrac- 
 tions are so shadowy, and words so fluctuating, that 
 they seem to elude even the perspicacity of Aristotle,
 
 PRELUDE TO CHAP. I. 57 
 
 and the ductility of his language. Essence is said 
 to be a genus, to be constitutive, that is, with matter, 
 which, in itself, is no particular thing, of each genus 
 of beings or things ; but then it is form, which 
 realises, so to say, that combination by conferring 
 upon it a specific character. For form harmonises 
 with all the organisation of an animal ; and every 
 organised body, Cuvier observes, over and above the 
 common qualities of its tissues, has a peculiar form, 
 not only generally and exteriorly, but even down to 
 its minutest details ; and it is " this form which de- 
 termines the direction of each particular movement, 
 which supports the complicity of its life, constitutes 
 its species, and makes it what it is 1 ." 
 
 1 Blainville, i"* ley on.
 
 BOOK THE SECOND. 
 
 CHAPTER I. 
 
 THUS have the opinions handed down by former 
 writers upon Vital Principle been delineated ; and 
 now let us retrace our steps, and again, as if at the 
 outset of our inquiry, endeavour to define what it is 
 and what the most general expression for it. 
 
 We say, then, that essence is a particular genus 
 of entities, and that of it part is matter, which in 
 itself is not any one particular object, as it is other 
 than form and species from which each object derives 
 its particular denomination; and that, in the third 
 place, there is the derivative from both these. Now 
 matter is potentiality, species reality, and that in a 
 twofold acceptation, as knowledge and as reflexion ; 
 but bodies, and above all natural bodies, seem to be 
 essences; for they are, in fact, the origins of other 
 bodies. Among natural bodies some have and some 
 have not life ; and by life we mean the faculties of 
 self-nourishment, self-growth and self-decay. Thus,
 
 CH. I.] ARISTOTLE ON THE VITAL PRINCIPLE. 59 
 
 every natural body partaking of life may be regarded 
 as an essence ; but then it is an essence in combination, 
 as^ has been said. And since the body is such a 
 combination, being possessed of life, it cannot be 
 Vital Principle ; for as it is itself more truly subject 
 and matter, it cannot be among the subordinates of a 
 subject. It follows, then, that the Vital Principle 
 must be an essence, as being the form of a natural 
 body holding life in potentiality ; but essence is a 
 reality, the reality, that is, of a body such as has 
 been described. Now reality is, in the twofold signi- 
 fication, either of knowledge or of reflexion ; and that 
 it may be regarded as knowledge is manifest in that 
 sleep and watching co-exist as original properties, in 
 Vital Principle ; and equally manifest that watching 
 is analogous to reflexion upon knowledge, as that 
 sleep represents knowledge possessed but not em- 
 ployed. But knowledge pre-exists in the same indi- 
 vidual, and the Vital Principle is, therefore, the 
 original reality of a natural body endowed with life 
 in potentiality ; only this is to be understood of a 
 body which may be organised. Thus, the parts even 
 of plants are organs, but then they are organs which 
 are altogether simple, as the leaf is the covering of the 
 pericarp, and the pericarp of the fruit ; and the roots 
 are analogous to the mouth, for both take in food. 
 If, then, there be any general expression for every 
 kind of Vital Principle, it may be set down as " the
 
 60 ARISTOTLE ON THE [BK. II. 
 
 incipient reality of a natural body which is orga- 
 nised" 
 
 It is, therefore, to no purpose to inquire whether 
 Vital Principle and the body are one, any more than 
 whether wax and the impress upon it are one, or 
 whether the matter formative of any object and the 
 object formed are one ; for one and being have many 
 significations, but they are correctly designated as 
 reality. 
 
 It has thus been explained generally what the 
 Vital Principle is, and shewn that it is an essence, 
 in its abstract signification, which implies the par- 
 ticular mode of being in any particular body, as if 
 any instrument, an axe, for instance, were a natural 
 body, the mode of being in the axe would be, at 
 once, both its essence and its Vital Principle; for, 
 were it once to be withdrawn, then, save in name, it 
 could be an axe no longer. All this, however, relates 
 to an axe, but Vital Principle is the mode and the 
 cause of being, not in any thing like an axe but, 
 in a natural body, having within it a principle of 
 motion and of rest. 
 
 But what has been said may be better understood 
 by reference to the parts of a body. Thus, if the eye 
 were an animal, vision would be its Vital Principle, 
 as vision, abstractedly considered, is the essence of 
 the eye ; but the eye is the matter of vision, and if 
 vision be wanting, then, save in name, it is an eye no
 
 CH. I.] VITAL PRINCIPLE. 61 
 
 longer, any more than is that an eye which is repre- 
 sented in sculpture or painting. All that has here 
 been assumed of a part may be made applicable to 
 the whole living body; for, as there is an analogy 
 between part and part, so is there between the whole 
 sensibility and the whole sentient body, in the ratio 
 of its sensibility ; but this must be understood of a 
 body which yet retains its Vital Principle, and is, in 
 potentiality, alive. The seed and the fruit are the 
 representatives of such a body in potentiality ; and as 
 cutting is the reality of an axe, vision that of an eye, 
 so watching is the reality of Vital Principle ; which is 
 to the body what vision is to an eye, and its own 
 property to any instrument ; but this is to be under- 
 stood of a body in potentiality. Thus, as an eye is a 
 pupil and vision, so an animal is a body and Vital 
 Principle. 
 
 It is then obvious that neither Vital Principle nor 
 any of its parts, even granting that it may be divi- 
 sible, can be separate from the body ; for of some of 
 its parts it is the reality; and yet there is nothing to 
 preclude the possibility of some others being separate, 
 as there are some which do not contribute to the 
 reality of any body. It is doubtful, however, whether 
 the Vital Principle is the reality of a body in the 
 sense that a mariner is of his vessel. 
 
 Thus far, then, have we proceeded in our attempt 
 to define and delineate Vital Principle.
 
 PKELUDE TO CHAPTER II. 
 
 As the purport of this chapter is to determine the essen- 
 tial or characteristic properties of the Vital Principle 
 in order to attain to a solid definition, it commences, 
 very appropriately, with a short disquisition upon 
 that form, and a protest against any deviation from 
 its real purport ; and thus the argument of the 
 foregoing chapter is continued. The opening para- 
 graph is necessarily obscure, from the nature of its 
 topic, but it may be practically at least elucidated, 
 by reference to similar topics in the other works. 
 It is observed by Aristotle 1 , that the antecedent is, 
 absolutely speaking, more apprehensible than the 
 sequence, as a point e. g. is than a line, a line than a 
 surface, and a surface than a solid ; so too an unit is 
 more apprehensible than a number (for the unit is 
 the origin of all number), as a single letter is than 
 a syllable. But sometimes, on the other hand, 
 the reverse of this happens for as it is the solid, 
 
 1 Topica, vi. 4, 5.
 
 PRELUDE TO CHAP. II. 63 
 
 especially, which falls under the senses, so the twrface 
 is more apprehensible than the line, and the line 
 than the point; as the multitude (pi iro\\o\) are 
 already conversant with them, while the sequences 
 are to be acquired only by attention, or some peculiar 
 mental faculty. Thus, to speak generally, it is best 
 to gather knowledge concerning sequences through 
 their antecedents ; for this is by far the most scien- 
 tific mode of conducting an inquiry. In fine, what- 
 ever falls under the senses seems, from being familiar 
 to us, to be more apprehensible than principles or 
 causes, which are more or less abstractions ; as, the 
 falling of a stone seems to be more apprehensible 
 than the principle of Gravitation. But as the know- 
 ledge of any subject may be also acquired through 
 the study of its accidents, that is, its essential pro- 
 perties, so it is suggested that the knowledge of Vital 
 Principle may be arrived at through the study of 
 its faculties.
 
 CHAPTER II. 
 
 SINCE that which is evident and, when abstract- 
 edly considered, more apprehensible may be derived 
 from particulars which are by their nature obscure, 
 although to us more apparent, let us again attempt, 
 bearing this in mind, to attain to a comprehensive 
 view of Vital Principle. It is not only correct that 
 the wording of a definition should shew, as do most 
 definitions, what a thing is, but it ought also to 
 embody and make apparent the cause of its being 
 what it is. But the terms usually employed make 
 definitions to be kinds of conclusions; as if, for 
 instance, to the question "what is a quadrature?" it 
 be answered, that it is to find an equilateral rectan- 
 gular figure equal to another figure with unequal 
 sides, such a definition is the statement of the con- 
 clusion; if it be said that the quadrature is " the 
 discovery of a mean proportional," this conveys the 
 cause of the thing. 
 
 We say, then, resuming our inquiry at its outset, 
 that the animate is distinguished from the inanimate 
 by having life. Now the term life has many accepta-
 
 CH. II.] ARISTOTLE ON THE VITAL PRINCIPLE. 65 
 
 tions, but if one only of the following properties, 
 viz. mind, sensibility, locomotion, and rest, as well 
 as the motion concerned in nutrition, growth, and 
 decay be manifested in any object, we say that that 
 object is alive. And, therefore, all plants seem to be 
 alive, for they all appear to have within them a 
 faculty and a principle by which they acquire growth 
 and undergo decay in opposite, directions; for they do 
 not grow upwards exclusively, but they grow equally 
 in both these and all other directions, and are alive 
 throughout so long as they are able to imbibe nourish- 
 ment. It is possible for nutrition to subsist inde- 
 pendently of the other functions, but the others cannot 
 possibly, in mortal beings, subsist without it; and 
 this is manifest in plants, since no other than it has 
 been allotted to them. Thus, it is by this faculty of 
 nutrition that life is manifested in living beings, but an 
 animal is characterized above all by sensibility ; for 
 we say that creatures endowed with sensibility are 
 not merely living beings but animals, although they 
 may neither be motive nor change their locality. 
 Touch is the sense first manifested in all creatures, 
 and, as the nutritive faculty can be manifested inde- 
 pendently of Touch and other senses, so the sense of 
 Touch can be manifested independently of any other. 
 We call nutritive function that part of Vital Principle 
 of which plants partake ; but all animals appear besides 
 
 5
 
 66 ARISTOTLE ON THE [BK. II. 
 
 it to have the sense of Touch ; and we shall, hereafter, 
 explain why each of those functions has been allotted. 
 Let it suffice, for the present, to say that Vital Prin- 
 ciple is the source of the nutritive, the sentient, cogi- 
 tative and motive faculties ; and that by them it has 
 been defined. 
 
 It is easy, with respect to some of those faculties, 
 to perceive, whether any one of them is the Vital 
 Principle, or a part of Vital Principle, and if a part 
 whether it is distinct from other parts substantively, 
 or in an abstract sense only; but there are others 
 which seem to elude investigation. Thus, as some 
 plants appear, after having been divided, and after 
 the parts have been separated, still to be alive, as if 
 the living principle, in each plant, were in reality one, 
 in potentiality more than one, so we see the same 
 occurrence in other distinctions of the Vital Principle, 
 as in insects which have been divided ; for each of 
 the parts manifests sensibility and locomotion, and if 
 sensibility, then imagination and desire, as wherever 
 there is feeling, there must be sense of pain and plea- 
 sure, and wherever these, there must, of necessity, be 
 desire. We have nothing very certain to offer upon 
 the subject of the mind and the reflective faculties; 
 but the mind seems to be another kind of Vital Prin- 
 ciple, and alone to be capable of existing apart from 
 the body, as the everlasting exists apart from the
 
 CH. II.] VITAL PRINCIPLE. 67 
 
 perishable. Thus, it is manifest, from what has been 
 adduced, that the other parts of the Vital Principle 
 are not, as some say, distinct from the body, although 
 it is clear that, when considered absolutely, they are 
 different from it ; for the mode of being in a sentient 
 must differ from that in a cogitative being, since 
 feeling differs from thinking, and this applies equally 
 to other functions and faculties. All those faculties 
 besides belong to some animals, particular ones only 
 to others, and there are others to which one only 
 has been allotted, and this constitutes distinctions 
 among animals, the cause of which shall hereafter be 
 considered. But something very like this has taken 
 place with respect to the senses, for some animals 
 have them all; others have particular ones only, 
 and there are others again which have but one ; 
 but that one is Touch, which of all is the most 
 necessary. 
 
 As that by which we live and feel, like that by 
 which we understand, has a twofold signification, 
 since we speak of that by which we understand some- 
 times as Knowledge, and sometimes as the Vital Prin- 
 ciple, for we say that we understand by either of 
 them ; so equally does this apply to that by which 
 we are in health, and which sometimes refers to a 
 particular part of the body, and sometimes to the 
 whole body. Now, the two faculties alluded to, know- 
 
 52
 
 68 ARISTOTLE ON THE [BK. II. 
 
 ledge and health, are a form, a " specific something" 
 a " relation," and an action, as it were, of a recipient, 
 capable in the one case of knowing, and in the other 
 of maintaining health (for the action of creative ener- 
 gies seems to be innate in the impressionable and 
 suitably constituted subject), but the Vital Principle 
 is that by which we live, feel and think, from life's 
 outset; so that, although it may be the cause and 
 form, it cannot be matter and subject. Thus, the 
 essence has a threefold signification, as we have said, 
 in the sense of form, of matter, and the compound of 
 the two ; and of these matter is potentiality, and form 
 reality ; and since the living being is a compound of 
 the two, the body is not the reality of the Vital Prin- 
 ciple, but it, on the contrary, is the reality of a par- 
 ticular kind of body. On which account it is happily 
 assumed by some that the Vital Principle can neither 
 be without the body, nor be itself a body of any kind ; 
 for a body it is not, but yet it is something of the 
 body, and, therefore, present innately in the body, 
 and that peculiarly constituted. It is not, that is, in 
 any kind of body, as the earlier writers have main- 
 tained, when they attached it to a body without in 
 the least defining either the nature or quality of the 
 body; although it must be against all probability 
 that any kind of recipient should receive any thing 
 taken by chance. But here all takes place as might
 
 CH. II.] VITAL PRINCIPLE. 69 
 
 reasonably be expected for the realising influence 
 exists congenitally in its own subject, while yet 
 potential, and constituted of matter fitted for its 
 agency. It is then manifest, from what has been 
 adduced, that the realising influence and cause can act 
 only upon that which is potentially capable of be- 
 coming such or such a reality.
 
 PRELUDE TO CHAPTER III. 
 
 THE inquiry into the faculties and functions of living 
 beings is here continued, for the purpose of deter- 
 mining, through them, the source from which life is 
 derived; and the distinction between the animal and 
 vegetable kingdom is, incidentally, alluded to. That 
 distinction is placed in the presence or absence of 
 sentient properties; and so Lamarck 1 distinguishes 
 plants, by their want of irritability, that is sensi- 
 bility, from animals. 
 
 1 Hist. Nat. T. i. p. 77.
 
 CHAPTER III. 
 
 ALL the faculties of Vital Principle which have been 
 enumerated belong, as we have said, to some crea- 
 tures, some only of them belong to others, and there 
 are creatures again which have but one ; and we spoke 
 of those faculties as the nutritive, appetitive, sentient, 
 locomotive and cogitative. Of these, the nutritive 
 alone belongs to plants ; but to other beings both it 
 and the sentient have been imparted; and if the 
 sentient, then the appetitive, for appetite is desire, 
 passion and volition ; and all animals, without excep- 
 tion, have the sense of Touch. But the creature to 
 which sensibility has been imparted cannot but be 
 sensible of pleasure and pain, of what is grateful and 
 what painful ; and if sensible of these, it must have 
 desire, as desire is the appetite for what is grateful. 
 All such creatures, moreover, have the sense for food, 
 as they have Touch, which is that sense ; for all ani- 
 mals are nourished by what is dry and moist, warm 
 and cold, and Touch is the sense for judging of these 
 qualities. But it is only by chance that the Touch 
 can judge of other qualities, as neither sound, colour 
 nor odour contribute in aught to nourishment; and
 
 72 ARISTOTLE ON THE [BK. II. 
 
 savour is among tangible qualities. Hunger and 
 thirst are desires: the former for what is dry and 
 warm, the latter for what is liquid and cold ; and 
 savour is the condiment, as it were, for both. As, 
 however, we shall be more explicit upon those points 
 hereafter, it may, for the present, suffice to say, that 
 all such creatures as have the sense of Touch have 
 appetite ; it is uncertain whether or not they have 
 imagination, but this also shall be considered here- 
 after. There are creatures to which, besides those 
 faculties, locomotion has been imparted ; and others 
 again, as man, to which have been allotted both 
 reflexion and mind, together with any other and yet 
 nobler faculty, if such there be, than mind. 
 
 It is clear, then, that there can be but one defi- 
 nition for Vital Principle, as there is but one for a 
 geometrical figure; for as in geometry there is no 
 figure but the triangle and its sequences, so neither 
 are there any kinds of Vital Principle save those 
 which have been enumerated. Could there, however, 
 be any such common expression for figures, as with- 
 out being peculiar to any one, should yet be applica- 
 ble to all, so might there be for the Vital Principles 
 alluded to. It would be idle, however, to seek for 
 any such expression, in the case either of Vital Prin- 
 ciples or geometrical figures, as should neither be 
 applicable to any one of them individually, nor, put- 
 ting aside individuals, be applicable to them as an
 
 CH. III.] VITAL PRINCIPLE. 73 
 
 individual species. But still there is an analogy 
 between the faculties of Vital Principle and geometri- 
 cal figures ; for as in vital properties, so in geometri- 
 cal figures, the antecedent is ever present potentially 
 in the sequences, and as the triangle is in the square, 
 so the nutritive is in the sentient faculty. Thus, the 
 inquiry must be conducted with reference to indi- 
 viduals, in order to learn what is the Vital Principle 
 of each, as of a plant, a man, or a brute ; and where- 
 fore beings are thus ranged in a series. 
 
 Without the nutritive function there can be no 
 sensibility, but in plants the nutritive exists without 
 the sentient ; so again without the Touch there can 
 be no other sense, while Touch can exist alone, for 
 many animals have neither sight nor hearing, and are 
 altogether without smell. Among sentient creatures 
 some have and some have not locomotion, and, finally, 
 to a few calculation and judgment have been imparted; 
 and to such among mortal beings as are so endowed 
 all other faculties have been imparted likewise. But 
 to such as possess some one only of the faculties, 
 calculation has not been allotted, as some of them 
 have not even imagination, while others live by it 
 alone ; it would be foreign to our present inquiry to 
 enter upon the speculative intellect. 
 
 It is, then, clear that the definition which comes 
 closest to each one of those faculties is also the fittest 
 for the elucidation of Vital Principle.
 
 I 
 PRELUDE TO CHAPTER IV. 
 
 THE opening paragraphs of this chapter are both obscure 
 and apparently contradictory ; for while it is sug- 
 gested that it might be well, in order to comprehend 
 faculties or functions, first to study the energies or 
 organs from which they emanate, yet the inquiry 
 reverts to nutrition as a fact ; without reference, 
 that is, either to vital processes or to food. We 
 may assume that Aristotle was unacquainted with 
 the rudimentary forms and development of the 
 corporeal organs, and yet, judging from this exor- 
 dium, he seems to have perceived that every part 
 must advance from a nascent state to its perfected 
 condition; and thus he has suggested the teaching 
 of developmental anatomy. As the inquiry proceeds, 
 we are reminded of the obscurity or inaccuracy of 
 language, in portraying the impressions upon and 
 the functions, so to say, of the sentient organs 
 even now the external object is, with us, in common 
 parlance, a sensible object ; sensation, besides its own
 
 PEELUDE TO CHAP. IV. 75 
 
 sense, implies casual feelings from within ; sight 
 signifies both faculty and function ; and nourish- 
 ment is food as well as digestion. It is somewhat, 
 pei'haps, objectionable that Aristotle should have 
 bound up, so to say, the generative with the nutri- 
 tive function, seeing how they differ both in the 
 periods of development and duration ; they are 
 equally necessary, no doubt, to nature's design, but 
 still they are neither contemporaneous nor identical. 
 With respect to spontaneous generation here alluded 
 to Aristotle 1 admitted its possibility, and for obvious 
 reasons, in the case of eels j and, although he denied 
 that all mullets (TOUC K6<rTpe?e (j)ve<r6ai Trai/Tas) are 
 so reproduced, yet he believed that some of the 
 species spring forth (^U'CTOJ) from the mud and sand 
 on the sea-shore ; and thus it is evident, he continues, 
 that some creatures, not being derived from others, 
 may be the product of spontaneous generation. This 
 opinion upon reproduction prevailed for many ages, 
 and even yet, perhaps, notwithstanding the advance- 
 ment of science, it may not be altogether discredited. 
 
 1 Hist. Ani. vi. 14. 14. 15. 3.
 
 CHAPTER IV. 
 
 IT is necessary, in order well to study those faculties, 
 that we should comprehend what each of them indi- 
 vidually is, and then, in like manner, carry our inquiry 
 into their consequences and other conditions. But if 
 it behove us to say what each of them is, as what is 
 the cogitative, sentient, or appetitive faculty, it should 
 previously be settled what that is which thinks and 
 that which feels ; for energies and acts are, abstract- 
 edly considered, pre-existent to their functions. Grant- 
 ing, however, that it is so, and that we ought, before 
 the faculties or functions, to have considered their 
 opposites, it might be fitting here also, and for the 
 same reason, first to define the opposites of the func- 
 tions define, that is, food before nutrition ; the object 
 before perception ; and the intelligible before thought. 
 Thus we must first speak upon nutrition and 
 generation, for the nutritive faculty is innate in other 
 beings besides animals ; it is the primal and most 
 universal influence of the Vital Principle, and through 
 it life is manifested in all beings. Its functions are 
 to generate and to employ nourishment ; for the most
 
 CH. IV.] ARISTOTLE ON THE VITAL PRINCIPLE. 77 
 
 natural of the functions in beings which are perfect, 
 that is, which are neither dwarfed nor spontaneously 
 generated, is to produce another such as itself, an 
 animal an animal, and a plant a plant, in order that 
 they may partake, to the extent which has been 
 allotted to them, of the Everlasting and the Divine. 
 All creatures yearn after this, and, for the sake of it, 
 they do all that they do naturally ; but since such 
 beings cannot, in uninterrupted continuity, partake of 
 the Everlasting and the Divine, because no perishable 
 being can abidingly continue as one and the same ; 
 yet each can partake thereof in its own allotted por- 
 tion, be it larger or smaller, and still continue, if not 
 the same, like the same, and one, if not in number, as 
 species. 
 
 The Vital Principle is the cause and the origin of 
 a living body. Now, cause and origin have several 
 significations ; for the Vital Principle is equally a 
 cause, according to any one of the three defined modes 
 of causation : as that whence motion proceeds ; as 
 that for which motion is produced ; and cause, again, 
 as the essence of living bodies. It is evident that it 
 is a cause as an essence, since the essence is in all 
 things the cause of their being what they are ; and 
 as life is the mode of being in living beings, so Vital 
 Principle is the cause and the origin of all such. It 
 is the realizing principle, besides, the cause that is of 
 something which exists in potentiality becoming a
 
 78 ARISTOTLE ON THE [BK. II. 
 
 reality. It is manifest, too, that Vital Principle is a 
 cause, in the sense of a final cause ; for as the mind 
 acts for some end, so does nature, and that end is her 
 aim ; and such an aim has the Vital Principle, by its 
 nature, in living bodies. Thus, all natural bodies, 
 those of animals as well as those of plants, are its 
 instruments, and are what they are for its purposes. 
 The term final cause has a twofold signification, as 
 it implies that for which, as well as that by which, 
 any result is obtained; and Vital Principle is a, final 
 cause, as that whence locomotion is derived, although 
 this is a property which does not belong to all living 
 creatures. Change and growth, moreover, are depen- 
 dent upon Vital Principle ; for sensation seems to be 
 a change of some kind, and whatever is sentient has 
 Vital Principle ; and this applies equally to growth 
 and decay, for nothing grows or decays naturally 
 unless it be nourished, and nothing is nourished which 
 does not partake of life. Empedocles has not ex- 
 pressed himself happily upon this point, as, after other 
 observations, he adds that plants take growth down- 
 wards, where they strike root, from this being the 
 natural direction of earth, and upwards, from this 
 being the natural direction of fire. Neither has he 
 clearly seized the import of the terms upwards and 
 downwards, as they are not identical for all creatures, 
 or for the universe ; for the nead is to animals what 
 the roots are to plants, if we may speak of organs
 
 CH. IV.] VITAL PRINCIPLE. 79 
 
 after their functions, although in other respects dif- 
 ferent. But, besides these objections, what is that 
 which is to hold fire and earth, with their opposing 
 tendencies, together ? Now, unless there be a restrain- 
 ing force, they must be torn asunder, and if such 
 there be, it ought to be regarded as Vital Principle, 
 and the cause both of nourishment and growth. 
 
 The nature of fire seems, to some philosophers, to 
 be the absolute cause of nutrition as well as growth, 
 and that because it alone, among bodies or elements, 
 appears to be nourished and to grow. It might, 
 therefore, be assumed, that it is fire which works out 
 those processes in plants and animals ; but although 
 fire is possibly a joint cause, it cannot be the exclusive 
 cause, as this must be assigned rather to the Vital 
 Principle. The increase of fire is infinite, so long as 
 there is any thing combustible, but to all the bodies 
 of nature's constitution there is a limit and a relation 
 both as to bulk and increase ; and these are conditions, 
 not of fire but of Vital Principle ; not of matter but 
 of design. 
 
 Since the same faculty of Vital Principle is at 
 once nutritive and generative, it is necessary first to 
 define nutrition ; for it is by this, compared with other 
 faculties, that Vital Principle is especially distin- 
 guished. Nutrition, then, appears to be a contrary 
 acted upon by a contrary, but this does not imply any 
 kind of contrary by any other contrary ; it refers only
 
 80 ARISTOTLE ON THE [BK. II. 
 
 to such contraries as can generate from and give 
 growth to one another. Thus, there are many things 
 derived from one another which are not always quan- 
 tities, as the healthy, for instance, is derived from the 
 unhealthy ; neither do these contraries appear, in any 
 manner, to be nourishment for one another, as water, 
 for instance, is nourishment for fire, but fire is not 
 nourishment for water. It is in homogeneous bodies 
 especially, that the contraries seem to be in the rela- 
 tions of nourishment and nourished. But here there 
 is a difficulty ; for while some maintain that like is 
 nourished as it is increased by like, there are others 
 who maintain, as we have said, that it is contrary 
 which is nourished by contrary ; that like is unim- 
 pressionable by like ; that food undergoes change and 
 is digested, and that all -change implies conversion to 
 an opposite or an intermediate state. Nourishment, 
 besides, is affected by the body which is nourished, 
 although the body is not affected by the nourishment, 
 just as the material is affected by the artisan, although 
 he is not affected by the material ; for it is the artisan 
 alone who converts the material from a raw state into 
 one of usefulness. There is, however, a distinction to 
 be observed in nourishment, between its last and ad- 
 ventitious or its first state ; if both states are nourish- 
 ment, distinguished only by the one being undigested, 
 and the other digested, then it may be correct to 
 admit of both explanations for nutrition; for in so
 
 CH. IV.] VITAL PRINCIPLE. 81 
 
 far as food is undigested, it is contrary nourished by 
 contrary, and in so far as it is digested, it is like 
 nourished by like. Thus, it is manifest that both 
 these opinions are in one sense right, and in another 
 wrong. But as nothing can be nourished which does 
 not partake of life, so a living body may be regarded 
 as a body which is nourished from having life ; and 
 thus nutrition is not in a casual, but a positive rela- 
 tion to a living body. There is an obvious distinc- 
 tion between nourishment and growth : in so far as a 
 living body is quantity, it is capable of growth, and in 
 so far as a something is matter and essence, it is nourish- 
 ment ; for it preserves the essence of the body, which 
 exists so long as it can be nourished. Nourishment, 
 however, does not generate that which is nourished, 
 as it is the same as it ; for it is already itself the 
 essence, and nothing can generate, although it may 
 preserve itself. Thus, it is the same faculty of Vital 
 Principle which is able to preserve that, such as it 
 may be, which contains it, and it is nourishment 
 which renders it fit for its office ; and, therefore, when 
 deprived of nourishment, it can exist no longer. 
 
 Now, there are here three things or conditions 
 something to be nourished, something by which 
 nourished, and something which nourishes. That 
 which nourishes is the primal or nutritive faculty ; 
 that which is nourished is the body ; and that by 
 which nourished is food. And as things are correctly 
 
 6
 
 82 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. II. 
 
 designated after the object to which they tend, and 
 as the object here is to generate another like itself, 
 so the primal faculty may be set down as being 
 generative of another like itself. That "by which 
 nourished" has a twofold signification, as has that 
 by which a vessel is steered, and which implies hand 
 and rudder, of which the one only moves, while the 
 latter both moves and is moved. It is necessary to 
 nutrition that food should admit of being digested, 
 and as it is heat which works out digestion, so all 
 living creatures have heat. 
 
 It has thus then be shewn, although but super- 
 ficially, what nutrition is ; but the subject shall be 
 further elucidated in other treatises upon the subject.
 
 PKELUDE TO CHAPTER V. 
 
 ARISTOTLE, having fully inquired into the process of nutri- 
 tion, here enters upon the investigation of the sensi- 
 bility or sentient system, which is, as he said, the 
 line of separation between animal and vegetable 
 existence ; the inquiry includes, of course, the senses 
 and their organs, as well as allusions to those ex- 
 ternal forces or qualities which by their action pro- 
 duce simultaneous perception, that is, sensation. 
 Sensibility is one of the great mysteries of our 
 mortal nature, but its investigation was, in that age, 
 additionally complicated and abstruse, as the brain 
 as well as its relation to the spinal cord and con- 
 nexion with the organs of the senses were unknown. 
 But, although anatomy has detected the links between 
 the brain and sentient organs, and thus shewn that 
 the senses are emanations, so to say, from it, yet this 
 knowledge, however otherwise valuable, does not 
 explain how matter has been constituted thus to 
 produce sensation, and, by reflexion, consciousness. 
 
 62
 
 CHAPTER V. 
 
 LET us now proceed, as those subjects have been 
 scrutinized, to speak upon sensation in its widest 
 acceptation. 
 
 Sensation is the combined result, as has been said, 
 of a motion and an impression, for it seems to be some 
 kind of change ; and some writers maintain that it is 
 only like which is impressionable by like, but we 
 have already, in our treatises " upon action and im- 
 pression" shewn how far the opinion is or is not 
 tenable. But it is difficult to understand why there is 
 no sensation from the senses of themselves, that is, 
 why, without the presence of external objects, the 
 senses do not give out sensation, although fire, earth, 
 and the other elements, from which or the accidents 
 of which sensation is derived, are present in them. It 
 is evident that it is because the sensibility is not in a 
 state of activity, but is only in potentiality; and, 
 therefore, that it is with it as with a combustible ma- 
 terial, which alone, without something on fire, does 
 not burn ; for otherwise it might set fire to itself, and 
 would stand in no need of fire, in reality, for the purpose. 
 Since we speak of sentient perception in a two-fold
 
 CH. V.] ARISTOTLE ON THE VITAL PRINCIPLE. 85 
 
 sense, (for we speak of one who hears and sees, in po- 
 tentiality, as " one hearing and seeing," although he 
 may happen to be asleep, and we say the same of 
 one who is actually employing those senses,) so may 
 sensation be spoken of in two ways, as subsisting in 
 potentiality and subsisting in activity. Let us, how- 
 ever, before proceeding further, observe that impres- 
 sion, motion, and action are for us equivalent terms 
 for motion is a kind of action, although an action 
 which is incomplete, as has been elsewhere explained. 
 Now, all things which are impressed and set in motion 
 are so affected by something capable of making im- 
 pression and existing in activity; so that impression 
 is in one sense by like, and in another sense by un- 
 like, as we have said for the unlike is subject to 
 impression, but, having been impressed, it is con- 
 verted into like. A distinction, however, must be 
 drawn between the terms potentiality and reality, for 
 we are now going to employ them in an absolute 
 sense any individual whatever, then, may be learned, 
 as we might speak of any man as learned, because 
 man is among beings capable of learning and being 
 learned ; and so we speak of a man as learned, from 
 his actually professing, at the time, grammatical or 
 other knowledge. 
 
 Thus, each of these individuals is learned in po- 
 tentiality, although in a different manner the one 
 is so because he is of a certain genus and peculiar
 
 86 ARISTOTLE ON THE [BK. IT. 
 
 matter; and the other, because he can when he will 
 reflect upon his knowledge, provided there is no ex- 
 ternal impediment to his doing so. It is this one only, 
 however, when actually reflecting upon his know- 
 ledge, being in activity, and fully acquainted with 
 some one subject, as A. for instance, who is to be ac- 
 counted learned in reality. Both those first men, in 
 fact, are learned in potentiality; but the one is so 
 from having been modified by learning, and under- 
 gone frequent changes from one habit to an opposite 
 one; and the other is so from possessing sensibility 
 or rudimentary learning, and being able, although in 
 a different manner, to pass from inertia to activity. 
 
 But the term impression is not absolute in signifi- 
 cation, as sometimes it implies a kind of destruction 
 by a contrary, and sometimes it signifies rather pre- 
 servation of something being \n. potentiality by some- 
 thing which is in reality and like, in the relation that 
 potentiality bears to reality. Thus, the possession of 
 knowledge implies the power of reflecting upon it, 
 and this either is not change, being but an increase of 
 knowledge and a step towards its completion, or it is 
 change of a different kind. It is not correct, there- 
 fore, to say that an individual, when thinking, is un- 
 dergoing change, any more than that a builder, when 
 employed in building, is undergoing change; so that 
 the process by which an individual passes, as to his 
 thinking and reflecting faculties, from potentiality to
 
 CH. V.] VITAL PRINCIPLE. 87 
 
 reality, ought to have some other appellation than 
 that of instruction. We may not then, as has been 
 observed, say of the individual who, from being in 
 potentiality, learns and receives knowledge from one 
 who is in reality and able to teach, that he suffers 
 impression, or else it must be admitted that there are 
 two modes of change, one in privative dispositions, 
 and another over habits and nature. The first change, 
 however, of this kind in the sentient being comes 
 from the parent at the moment of conception; as 
 from that moment the being has, as it were, learning 
 and sensibility. There is an analogy between the 
 state of activity and reflexion just alluded to, but 
 with this difference, that the impressions productive 
 of activity, as the audible, the visible, and others, are 
 all derived from without; and the cause of this is 
 that sensation, in activity, is employed upon particu- 
 lars, knowledge upon universals ; and universals are, 
 in some way, in the Vital Principle itself. The act 
 of thinking, therefore, is dependant only upon the will 
 of the individual, which is not the case with sentient 
 perception, as for it there must of necessity be ob- 
 jects to be perceived; and this holds good, and for 
 the same reason, with respect to the sciences which 
 are engaged upon external objects, because all such 
 objects are among particulars, and are external to the 
 percipient. But an opportunity may hereafter present 
 itself for the further elucidation of the subject.
 
 88 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. II. 
 
 Let it, for the present, suffice to say, that the 
 expression being in potentiality has not an absolute 
 signification, for it may be understood of a boy as 
 being qualified potentially to be a General, and also 
 of an individual of suitable age for the office ; and the 
 term sensibility is subject to like modifications of 
 meaning. But as the distinction between these two 
 states of sensibility is without any special appellation, 
 although it has been shewn that there is a distinction 
 between them and what the distinction is, it has been 
 found necessary to employ the terms impression and 
 change, as if their signification were unequivocal ; but, 
 as has been said, the sentient principle is, when in 
 potentiality, analogous to the external object when in 
 reality. 
 
 The sentient principle, in fact, suffers impression 
 when unlike; but, having been impressed, it is con- 
 verted into like, and becomes the same as that by 
 which the impression is made.
 
 PRELUDE TO CHAPTER VI. 
 
 THIS chapter, adopting a former suggestion, commences 
 with the nature and influences of the objects and 
 properties which act upon the senses. As those pro- 
 perties or influences, however, whatever their denomi- 
 nation, light, sound, odour, savour, motion, number 
 <kc., are considered in their relation to the senses, 
 respectively, they here are merely characterized under 
 the terms, which are defined, of peculiar and common. 
 Casual or chance perception is exemplified by a figure 
 which is far from being apparent.
 
 CHAPTER VI. 
 
 LET us, before proceeding further, speak upon the ob- 
 jects of perception in relation to each of the senses. 
 The object of perception is spoken of in a three-fold 
 manner, as there are two ways in which we speak of 
 perceiving objects distinctly, and one in which we 
 speak of perceiving them accidentally; and of those 
 two ways one signifies the property which is peculiar 
 to each sense, and the other the property which is 
 common to all the senses. I mean by peculiar pro- 
 perty that which cannot be perceived by any other 
 than its own sense, and concerning which that sense 
 cannot be deceived as colour for sight, sound for 
 hearing, and savour for taste. The touch, indeed, 
 discriminates several differences of quality, but every 
 other sense distinguishes only its own subjects ; and 
 thus sight or hearing is never deceived as to whether it 
 is colour or sound which is seen or heard, although it 
 may be deceived as to what or where the coloured, 
 what or where the sonorous body may be. 
 
 Such then the properties which are said to be 
 peculiar and to belong to particular senses ; but there
 
 CH. VI.] ARISTOTLE ON THE VITAL PRINCIPLE. 91 
 
 are properties, such as motion, rest, number, form and 
 magnitude, which are termed common, as they belong 
 not to any one sense, but to all in common. Thus, 
 there is a movement which is perceptible both by 
 Touch and Sight. An object is said to be perceived 
 accidentally when, for example, something white 
 may be the Son of Diares for the percipient is sen- 
 sible of the individual accidentally, because of his 
 being an accident of that which is perceived; and, 
 therefore, no impression is made by that which is 
 perceived, as a special object, upon the percipient. 
 
 The properties of bodies, which are in them- 
 selves perceptible, are, strictly speaking, peculiar 
 properties ; and to such each particular sense is natu- 
 rally and essentially related.
 
 PRELUDE TO CHAPTER VII. 
 
 THE treatise commences the examination of the senses 
 with the Sight, and closes with the Touch, which is 
 somewhat contrary to Aristotle's estimate of their 
 relative importance ; for he has shewn that the Touch 
 is the first, as it is the most universal of all the 
 senses, as well as essential to animal existence. Thus, 
 this sense is to sentient creatures what nutrition is 
 to other beings ; for as without Touch there can be 
 no animal, so without nutrition there can be no life. 
 Descartes, more in accordance with Aristotle's teach- 
 ing, begins with the Touch, and then proceeds to the 
 Taste, Smell, Hearing and Sight ; and so Grant ' makes 
 " all the other senses to be but modifications of the 
 Touch." Cuvier, however, reverses this it may be 
 general order, and treats of the special senses before 
 the Touch. It may be well to observe, that the 
 senses as well as their modes of excitation, had been 
 
 1 Outlines of Comp. Anat. e. vi.
 
 PRELUDE TO CHAP. VII. 93 
 
 treated of in a distinct work ', which may be regarded 
 as supplementary to the present treatise ; and this 
 will explain why the eye and vision are here very 
 briefly alluded to, while particular attention has 
 there been given to the ear and hearing. 
 
 CHAPTER VII. 
 
 THE visible is that for which vision is the sense, and 
 the visible is both colour and something which is de- 
 scribable by words, although it happens to be without 
 a name; but our meaning will become clear to those 
 who accompany us in the inquiry. The visible is 
 colour, and colour is that which is upon something 
 visible in itself; and this something is visible, not 
 only after its appellation but, because it has in itself 
 the cause of being visible. All colour is motive of 
 the diaphanous, in activity, and to be so motive is the 
 nature of colour. On which account nothing is visi- 
 ble without light, but the colour of each object is 
 visible in the light; and we must, therefore, first say 
 what light is. There is a something diaphanous, and 
 I call diaphanous what is visible, and yet not visible, 
 
 1 De Sentu et Sens. i. 10.
 
 94 AEISTOTLE ON THE [BK. II. 
 
 strictly speaking, in itself, but made visible by colour, 
 which is foreign to it. Such is air, and water, and 
 many solid bodies; yet neither air nor water, as air or 
 water, is diaphanous, but the same nature is present 
 in both those elements, which is in the eternal super- 
 nal body. Light is the active state of that same dia- 
 pkanous, in so far as it is diaphanous, and darkness is 
 the same in its state of potentiality. But light is the 
 colour, as it were, of the diaphanous, when made dia- 
 phanous in reality by fire, or other such element as 
 the supernal body; for to it belongs a something 
 which is identical with fire. We have thus said what 
 is the diaphanous and what light, and have shewn 
 that neither of them is fire, nor a body, strictly speak- 
 ing, nor an emanation from a body, (as, in that case, 
 they would be corporeal), but that they are the pre- 
 sence in the diaphanous of fire or something analogous 
 to fire, since two bodies cannot possibly coexist in 
 one and the same body. 
 
 Light seems to be the opposite to darkness ; and 
 as darkness is the absence of a particular state of the 
 diaphanous, it is evident that the presence of that 
 state must be light. 
 
 Thus Empedocles, or whoever else may have held 
 the same opinion, was wrong in supposing that light 
 was transported and manifested, without our con- 
 sciousness, between the Earth and surrounding space; 
 for the opinion is opposed as well to sound conclusion
 
 CH. VII.] VITAL PRINCIPLE. 95 
 
 as to observation of the phenomenon. If the interval 
 were small, the fact might, indeed, escape us; but, 
 extended as it is from the East to the West, the pos- 
 tulate is too extravagant to be admitted. 
 
 Now that which is without colour is receptive of 
 colour, as that which is without sound is receptive of 
 sound; and that which is without colour is the dia- 
 phanous and the invisible or scarcely visible, such as 
 darkness seems to be. Such too is the diaphanous ; 
 but then it is the diaphanous, not in potentiality but, 
 in reality; for the same nature is sometimes darkness 
 and sometimes light. But all objects are not visible 
 in light, as there are some of which the peculiar 
 colour only of each is visible; for some, not visible 
 in light, produce sensation in the dark, as certain 
 fiery brilliant appearances (which have no special 
 appellation,) which emanate from fungi, horn, scales 
 and eyes of fishes, but the peculiar colour is not seen 
 of any one of those objects. It is foreign to our present 
 purpose to explain how such objects become visible ; 
 but this much is manifest, that it is colour which is 
 visible in light. Therefore, without light colour is 
 not visible; for it is an essential property of colour to 
 be motive of the diaphanous in activity, and the 
 reality of the diaphanous is light. As proof of this, 
 if any coloured object be placed over the sight, the 
 object will not be seen, and yet there is colour, which 
 is motive of the diaphanous, the air, that is, and, by
 
 96 ARISTOTLE ON THE [BK. II. 
 
 its being continuous between the object and the sense, 
 it is able to give motion to the visual organ. Thus. 
 Democritus was wrong in thinking that if the medium 
 were a void, vision would be so accurate as to render 
 an ant visible in the sky. The opinion, in fact, in- 
 volves an impossibility; for vision is produced by 
 some kind of impression upon the visual organ, and 
 as this cannot possibly be effected by the colour which 
 is visible, there remains only that it must be by the 
 medium, and thus a medium there must be ; so that 
 if there were a void, vision would be, not to say in- 
 accurate but, altogether precluded. 
 
 It has thus then been said why colour must be 
 visible in the light ; but fire is visible both in dark- 
 ness and in light, and necessarily so, since it is by fire 
 that the diaphanous becomes diaphanous. The same 
 reasoning holds good for sound and for odour, as 
 nothing sonorous or odorous can produce sensation 
 when in immediate contact with the sentient organ ; 
 but by odour or sound the medium is set in motion, 
 and by it the organ is moved. Thus, when any thing 
 sonorous or odorous is placed immediately upon the 
 sentient organ, no sensation is given out ; and this is 
 the case with the sense of Touch, although less evi- 
 dently so ; but the cause of this shall be explained 
 hereafter. The air is the medium for sounds, while 
 that for odour has no special appellation, for there is 
 a particular impression common to air and water ; and
 
 CH. VII.] VITAL PRINCIPLE. 97 
 
 what the diaphanous is to colour that which is in 
 those elements is to odorous bodies, as aquatic ani- 
 mals appear to be sensible of odours. But neither 
 man nor animals which breathe can smell without 
 inspiring; and the cause of this shall be spoken 
 of hereafter.
 
 PKELTJDE TO CHAPTER VIII. 
 
 THIS chapter is upon sound and hearing ; and as these 
 subjects had been but desultorily alluded to in the 
 other works, they are treated of at some length on 
 this occasion. It opens with the distinction of 
 bodies into sonorous and insonorous, and after tracing 
 the analogy between the acute and grave, and the 
 sharp and blunt (of touch), it passes by a rapid 
 transition to the voice, which is dwelt upon at some 
 length. The term evtpycta, which had been used in 
 place of evT\-^fta, to express the active as opposed 
 to the potential or negative state of the diaphaneity, 
 is again employed here to signify the analogous and 
 contrasting quality of sound. The distinction between 
 the terms is not very apparent now, although this 
 may not have been the case then ; for the evepyeta 
 may have conveyed the idea of action in the transi- 
 tion from potentiality, and so have been more 
 expressive of actual, as opposed to virtual light or 
 sound. Thus, if sound be a quality or condition, it
 
 PRELUDE TO CHAP. VIII. 99 
 
 may be active, and it may be only virtual or faint ; 
 but although to us inaudible, it is not to be supposed 
 that silence any more than darkness is ever absolute ; 
 so that the text has limited the range of sound too 
 absolutely by the activity of the sense. Aristotle 1 
 assigned, as has been said, a high privilege to this 
 sense, because through it instruction is orally con- 
 veyed, and thus the blind from birth are more intel- 
 ligent ((ppovtutorepot), he observes, than "the deaf 
 and dumb;" but the argument would have been 
 more correct had the second term been omitted, as 
 individuals are of necessity dumb when hearing is 
 quite shut out. The phraseology, however, is still 
 sanctioned in common parlance. 
 
 1 De Sensu et sensili i. 1 1. 
 
 72
 
 CHAPTEE VIII. 
 
 LET us now proceed to determine the nature of sound 
 and hearing. Sound is double one actual and an- 
 other potential ; for we say that some substances, such 
 as sponge and wool, are without sound ; and that 
 others, as brass, and bodies which are hard and 
 smooth, have sound, because such objects are able to 
 sound ; are able, that is, to create actual sound by the 
 action of the medium between the object and the 
 hearing. Sound of the actual kind is the invariable 
 result of something in relation to something and in 
 something ; for its producing cause is percussion. It 
 is impossible, therefore, that sound should be pro- 
 duced when there is only one substance, as that which 
 percusses must be distinct from that which is per- 
 cussed; so that the sonorous object sounds by its 
 relation to another object. But there can be no per- 
 cussion without movement, and sound is not produced 
 by the percussion of any kind of substance, as we 
 have said, (since wool, however percussed, does not, 
 while brass and smooth and hollow bodies brass 
 because it is smooth do give out sound,) and hollow 
 bodies create, by reflexion, many percussions after the
 
 CH. VIII.] ARISTOTLE ON THE VITAL PRINCIPLE. 101 
 
 first, owing to the medium within them having been 
 set in motion and being unable to make its escape. 
 Sound is audible in air, and so it is in water, although 
 less distinctly ; but neither air nor water is the efficient 
 cause of sound, as for it there must be percussion of 
 solid bodies against each other and against the air, 
 and this is effected whenever the air, having been 
 percussed, remains, is not, that is, dispersed. Thus, 
 if the air be struck sharply and forcibly it gives out 
 sound ; for the motion of that which percusses should 
 anticipate the dispersion of the air, as if any one were 
 striking a rapidly moving heap or cloud of sand. 
 
 An echo is produced whenever the external air has 
 been more than once repelled by the air contained 
 within a vessel, by the sides of which that air is pre- 
 cluded from being dispersed, just as a ball rebounds. 
 It seems as though an echo ought to be a constant 
 occurrence, although it may not be audible, since that 
 happens to sound which happens to light, and light is 
 continually undergoing reflexion (for, otherwise, as 
 light could not be everywhere, darkness would pre- 
 vail beyond the spot illumined by the sun), but yet it 
 is not everywhere reflected, as it is from water or 
 brass or any other smooth body, so as to form a 
 shadow whereby we are able to distinguish the light 
 itself. 
 
 A Void is rightly said to be the sovereign cause 
 of hearing; for the air seems to be a void, and the
 
 102 ARISTOTLE ON THE [BK. II. 
 
 air, when moving continuously and as one body, is 
 creative of hearing. But, owing to its being very dif- 
 fluent, it gives out no sound, unless that which is 
 percussed be smooth ; when this, however, is the case, 
 the air becomes simultaneously one over the surface, 
 as the surface of every smooth body is one. Every 
 sonorous body is so constituted as to set in motion the 
 air which, by continuity, is one up to the hearing, 
 and the hearing is naturally connected with the air ; 
 and owing to sound being in the air, the air which is 
 without sets in motion that which is within. An ani- 
 mal, therefore, does not hear everywhere, neither does 
 the air penetrate everywhere; for the part to be set 
 in motion is a living part, and does not everywhere 
 contain air. The air itself, owing to its ready diffusi- 
 bility, is without sound ; but, when precluded from 
 being dispersed, its motion is productive of sound. 
 The air which is within the ears has been so immured 
 as to be immovable ; and this in order that the sense 
 may perceive accurately all variations of its move- 
 ment. It is for these reasons that we are able to hear 
 when in the water, as the water cannot gain access to 
 the congenital air, or pass into the ear through the 
 convolutions ; when, however, this does happen, there 
 is no hearing, any more than there is when the mem- 
 brane of the ear, which is to it what the skin over the 
 pupil is to the eye, is diseased. But proof is afforded 
 whether the hearing is perfect or not, in that the ear
 
 CH. VIII.] VITAL PRINCIPLE. 103 
 
 is constantly giving out sound, just as a horn does ; 
 for the air within the ears is continually moving in 
 some peculiar manner, and yet sound is foreign to 
 that air and forms no part of its properties. It is on 
 this account, however, that we speak of hearing by a 
 void and something resonant, because we hear by the 
 part which contains the air confined within it. 
 
 But is it that which percusses, or that which is 
 percussed, which gives out sound ? Or do both con- 
 tribute to its production, each in its own way? Now, 
 sound is the motion of something which admits of 
 being moved after the manner of bodies rebounding 
 from smooth surfaces, whereon they may have been 
 impelled. But every kind of body, whether percussing 
 or percussed, does not, as has been said, give out 
 sound ; as when a sharp point, for example, strikes a 
 sharp point, there is no sound ; but in order to pro- 
 duce sound, that which is percussed must be so 
 smooth, that the mass of air upon its surface may re- 
 bound from, and be agitated over it. The distinctions 
 among sonorous bodies are revealed in the actual 
 sounds which they give forth; for as without light 
 colours are not visible, so without sound the acute 
 and grave are not audible. These terms (acute and 
 grave) are derived from tangible properties, and em- 
 ployed, in a metaphorical sense, for sounds; for the 
 acute moves the hearing quickly and sharply, the 
 grave moves it slowly and dully ; not, however, that
 
 104 ARISTOTLE ON THE [BK. II. 
 
 the acute is quick or the grave slow ; but that such is 
 the motion of the one from the celerity, and such the 
 motion of the other from the tardiness of its operation 
 upon the sense. And there does seem to be an ana- 
 logy between those sounds and the sharp and blunt, 
 as perceived by the Touch ; for the sharp pricks, and 
 the blunt pushes, as it were, because the motion ex- 
 erted by the one is rapid, by the other tardy ; and it is 
 in this manner that the terms in question have origi- 
 nated. Let us here, however, close our observations 
 upon the nature of sound. 
 
 The voice is a sound produced by a living crea- 
 ture; for nothing inanimate speaks, although there 
 are objects, such as the flute, lyre, and others, which, 
 having range of note, harmony, and expression, are 
 said, from a resemblance between their tones and the 
 voice, to do so; and the voice does seem to have all 
 the variations of note possessed by those instruments. 
 Many creatures have no voice (as all the insan- 
 guineous, for instance, and some of the sanguineous, 
 as fishes), which is very understandable, seeing that 
 sound is a certain motion of the air ; and with respect 
 to those fishes which are found in the Achelous and 
 said to speak, they produce sound by their gills, or 
 other such part. But although the voice is a sound 
 emanating from a living creature, it does not imply 
 any kind of sound, or a sound produced by any 
 kind of part; and as all sound is produced by the
 
 CH. VIII.] VITAL PRINCIPLE. 105 
 
 conditions of something which percusses, something 
 percussed, and a something, that is the air, in 
 which percussion can be made, it might reasonably 
 be assumed, that such creatures only as take in air can 
 have a voice. Now, nature employs simultaneously 
 the air respired for two functions, just as she employs 
 the tongue for taste and for speech ; and of these the 
 former is necessary (and therefore imparted to most 
 creatures), and the latter, as an organ for interpre- 
 tation, is for their higher good ; so too does she 
 employ the breath both as necessary for tempering 
 the heat within (as shall be explained elsewhere), and 
 for the production of voice, which is for the welfare 
 of the individual. The pharynx is the organ of 
 respiration, for the sake of which is another part, the 
 lung, and it is owing to this part that quadrupeds 
 have more heat than other creatures. 
 
 It is the place about the heart which first needs 
 respiration ; and, therefore, it is necessary that the 
 air, during inspiration, should pass inwards; and 
 thus the percussion of the air respired by the living 
 principle in those parts, against the so-called trachea, 
 constitutes the voice. But every sound produced by 
 an animal is not voice, as we have said (for it is pos- 
 sible to produce sound by the tongue, as in coughing), 
 but in order to constitute the voice, there must be a 
 percussing living force, and the sound produced must 
 be expressive of something. The voice is, in fact, a
 
 106 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. II. 
 
 sound expressive of something it is not, that is, as 
 in coughing, a mere sound of the air inspired; and 
 speech is the percussion, by the living principle, of 
 the air in the trachea, against the trachea itself. As 
 proof of which, we are unable to speak when holding 
 the breath, that is, when we neither inspire nor 
 expire; for the act of holding the breath sets in 
 motion the air which is inspired. It is now manifest 
 why fishes, having no pharynx, are without a voice ; 
 and they have no pharynx, because they neither 
 admit the air nor breathe. It is foreign to our present 
 purpose, however, to inquire into the cause of their 
 having been thus constituted.
 
 PRELUDE TO CHAPTER IX. 
 
 MODERN science confirms Aristotle's judgment concerning 
 the nature of odour, for it is said "to be a curious 
 and interesting problem, requiring much more investi- 
 gation than it has hitherto received ;" and, according 
 to Cuvier *, " of all the substances which act upon our 
 senses, those which produce the sensation of smell 
 are the least known, although their impression has 
 the liveliest and deepest influence upon our economy." 
 But the reason assigned in the text for this relative 
 imperfection of our smell is indefinite and question- 
 able ; for " although man's nostrils are less compli- 
 cated than those of any animals save the quadrumana, 
 he is the only creature whose smell is fine enough to 
 be affected by unpleasant odours" It may be doubted, 
 besides, whether any sensation can be, as is implied 
 in the text, so pure as to be freed from all mental 
 or corporeal association ; but when man's smell is 
 
 1 R&gne Animal, T. i. 73.
 
 108 PRELUDE TO CHAP. IX. 
 
 compared with that of birds and beasts of prey, it 
 may be granted that, within a certain range of impres- 
 sions, it is relatively duller and coarser than with 
 them. It is, however, assumed, that sight and smell, 
 when perfect, have the faculty of perceiving colours, 
 and odours purely, unassociated, that is, with any 
 impression grateful or otherwise ; and thus, as man's 
 smell was held to be imperfect, he was supposed to 
 be sensible of odours as creatures with hard, that is, 
 compound eyes are of colours. For such creatures 1 
 (crustacea, insects and others), having their eyes 
 uncovered, being without lids that is, see objects 
 which are at a distance " indistinctly, and as if they 
 were looking through congenitally attached eye-lids." 
 
 1 Hist. An. i. 15. 16.
 
 CHAPTER IX. 
 
 IT is less easy to define smell and the odorous object, 
 than the subjects which have just been treated of, as 
 the nature of odour is not so clear to us as is that of 
 either sound or colour ; and the reason of this is, that 
 our sense of smell is inaccurate, is less delicate, in 
 fact, than it is in many animals. Thus, man has but 
 a coarse smell, and is never sensible of any thing 
 odorous without associating therewith an impression 
 of something painful or grateful ; and this seems to 
 indicate an organ imperfectly constituted. It is pro- 
 bable that colours are perceived by creatures which 
 have hard eyes in this same manner, and that shades 
 of colour invariably make upon them an impression of 
 something to be afraid of or otherwise. The human 
 race is circumstanced in a like manner with respect 
 to odours ; and there seems to be an analogy between 
 taste and kinds of savours, and smell and kinds of 
 odours, but as taste is a kind of touch, and touch of 
 all man's senses the most perfect, his taste is more 
 delicate than his smell. With respect to other senses, 
 man is far behind many animals, but he is especially
 
 110 ARISTOTLE ON THE [BK. II. 
 
 distinguished from them all by the accuracy of his 
 Touch ; and to this he is indebted for being of all the 
 most intelligent. As proof of which, individuals of 
 the human race are according to the constitution of 
 this sense and nothing else, clever or dull for those 
 with hard flesh are slow, and those, on the contrary, 
 with soft flesh are quick of understanding. 
 
 As one savour is sweet and another bitter, so it 
 is with odours ; but some bodies impart an analogous 
 savour and odour, impart, I mean, a sweet odour and 
 a sweet savour, while other bodies give out their 
 contraries. Some odours equally with savours are 
 termed pungent, sour, and oily, but, as we have 
 already explained, owing to their not being so dis- 
 tinguishable by us as savours, odours have derived 
 their appellations from these, on account of the simi- 
 larity of the objects from which they both proceed. 
 Thus, the odour from saffron and honey is called sweet, 
 that from thyme and other herbs of the kind pungent, 
 and so for other bodies and odours. 
 
 There is a close analogy between the other senses 
 and the hearing : for as it is sensible of the audible 
 and the inaudible, so is vision of the visible and invi- 
 sible, and smell of the odorous and the inodorous, 
 and by inodorous is meant whatever is either alto- 
 gether without odour, or has but a very faint odour ; 
 and a sense analogous to this is attached to the term 
 insapid.
 
 CH. IX.] VITAL PRINCIPLE. Ill 
 
 The smell is perceptive through a medium, such 
 as air or water, for aquatic animals seem to be sen- 
 sible of odour ; and so, likewise, are sanguineous and 
 insanguineous creatures, as well as those which wing 
 the air. Thus, some of these are to be seen proceeding 
 from a distance towards food, of which they have been 
 made sensible by the odour emanating from it. And 
 hence the difficulty of determining why, if other crea- 
 tures are sensible of odours in a like manner, man 
 alone can smell neither when expiring nor when 
 holding his breath but, only when inspiring ; and 
 this whether the odorous object be at a distance from 
 or close to him, or placed immediately within the 
 nostrils. It is common, it is true, to all the sentient 
 organs to be insensible to impressions when objects 
 are placed immediately upon them ; but it is peculiar 
 to man (as may be proved experimentally), to be 
 unable to perceive odours without inspiring. So that 
 as insanguineous creatures do not breathe, they ought 
 to have some other sense besides those spoken of, 
 but yet this cannot be, since they do perceive odour ; 
 for the perception of odour, whether agreeable or 
 disagreeable, is smell; and as these appear to 
 be destroyed by the same powerful odours as those 
 which destroy man (odours, for instance, from pitch, 
 sulphur, and other like substances), we must con- 
 clude that they have smell, although they do not 
 breathe.
 
 112 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. II. 
 
 The olfactory organ in man appears to differ from 
 that in other animals as his eyes differ from those of 
 creatures in which they are hard ; for man's eyes are 
 furnished with a rampart, and a kind of sheath in 
 lids, without the elevation and drawing asunder of 
 which he cannot see, while hard eyes, having no 
 such provision, are instantly sensible of whatever may 
 be present in the diaphanous medium. In accord- 
 ance with this, the olfactory organ is, in such crea- 
 tures, like the eye, uncovered ; but, in such as breathe, 
 it is furnished with a cover, which during inspiration 
 is lifted up, as the veins and pores are then dilated. 
 On which account, creatures which breathe cannot 
 smell while in the water, as in order to smell they 
 must inspire, and while in the water they cannot 
 possibly inspire. 
 
 In fine, odour is derived from what is dry, as 
 savour is from what is moist ; and the olfactory organ, 
 when in potentiality, is analogous to that from which 
 odour is derived.
 
 
 PRELUDE TD CHAPTER X. 
 
 THIS theory of taste and savour is adopted substantively 
 by modern physiology. Cuvier ' says that " Taste is 
 only a more delicate kind of Touch ;" and Miiller 2 
 
 considers fluid essential to its manifestations. There 
 
 f 
 
 are three conditions essential to Taste, he observes, 
 the specific nerve, the excitation of that nerve through 
 savour, and the solution of the savour in the moisture 
 of the sapid organ ; for sapid matter to be tasted, 
 must either be moistened, or else be solvable in the 
 tongue's moisture. All which implies that, if an 
 object is very arid, or if the organs of Taste are 
 incapable of supplying moisture, the percipient will 
 be sensible, not of sapid but, of tangible qualities only, 
 such as hot and cold, hard and soft. 
 
 1 Rbgne Animal, I. 31. 
 
 3 Handbuch der Physiologic, Lib. II. 489.
 
 CHAPTER X. 
 
 THE sapid object is a kind of tangible object, and 
 this is the reason why it does not require, in order to 
 be perceived, any other medium than the body, for 
 the Touch requires no other. The body in which is 
 savour, is the gustable body, and the matter of savour 
 is in fluid, and fluid is something tangible. Thus, 
 were we in the water, and were any thing sweet cast 
 into the water, we should be sensible of the sweetness, 
 not through the water as a medium but, from its 
 having been mixed with the water as with a potable 
 fluid. Colour, however, is not thus made visible from 
 having been mixed with anything, nor is it made 
 visible by emanations ; and as the medium, in the 
 case of colours, plays no part and colour is the visible, 
 so is savour the gustable. No object, however, with- 
 out humidity can impart the sense of savour; and, 
 therefore, every sapid object contains humidity, in an 
 active or a potential state, as does salt ; for salt is 
 readily moistened and liquefied by contact with the 
 tongue. 
 
 Now, vision is perceptive of the visible and the 
 invisible (for darkness, although invisible, is still
 
 CH. X.] ARISTOTLE ON THE VITAL PRINCIPLE. 115 
 
 judged of "by vision), and a very bright light (which 
 is also invisible, although in a manner different from 
 darkness), and so hearing is equally perceptive of 
 sound and silence, of which that is audible and this 
 inaudible, as well as a very loud sound, just as vision 
 is of a very bright light ; for as a very low sound is, 
 in a certain sense, inaudible, so is a very loud and 
 crashing sound. On the other hand, the term in- 
 visible, used absolutely, is analogous to the term im- 
 possible upon other subjects, and which may be sig- 
 nificant of something generated without parts or with 
 parts ill formed for their office, as an animal without 
 feet, or a fruit without a kernel. So, too, the taste in 
 its turn is perceptive both of what is sapid and in- 
 sapid; and the insapid implies whatever has a faint 
 or nauseous savour, or a savour altogether perversive 
 of taste. The potable and the impotable seem alike 
 to be the origin of taste, for they both are sapid ; but 
 then the first has a nauseous savour, and is perversive 
 of taste, while the last is genial to the sense ; the po- 
 table is common, besides, to the touch and taste. 
 Since whatever is sapid is humid, it follows that the 
 organ of taste may neither be humid realty, nor yet 
 be incapable of becoming humid ; for the taste suffers 
 impression by the sapid body, in so far as it is sapid. 
 It is, therefore, necessary that the sentient organ, if 
 not moist, should, for its function, be capable of be- 
 coming so : and, as proof of this, the tongue, when 
 
 82
 
 116 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. II. 
 
 very dry or very moist, is not sensible of sapid im- 
 pressions as in the former instance, it is a tangible 
 rather than a sapid impression which is made by a 
 fluid when first tasted; and when very moist, it is 
 sensible only of the fluid already present, just as it 
 happens when, after tasting something pungent, we 
 proceed to taste a different fluid. It is thus that all 
 savours appear to the sick to be bitter, because the 
 tongue, with which they taste, is charged with a mois- 
 ture having that savour. 
 
 Kinds of savour are, like shades of colour, simple 
 when in broad contrast as the sweet and bitter with 
 their sequences, of the former the oily and of the lat- 
 ter the brackish ; and intermediate to these are the 
 pungent, rough, astringent, and sour, which seem to 
 include almost all the varieties of savour. 
 
 In fine, the sapid sense, when in potentiality, is 
 such as is the sapid object; and the sapid object, 
 when in reality, is productive, in the sense, of its own 
 savour.
 
 PRELUDE TO CHAPTER XL 
 
 COMMENTATORS have differed widely in their interpretation 
 of Aristotle's meaning in the opening passage upon 
 the Touch. But it may, with some confidence, be 
 assumed that, from being unacquainted with the 
 nervous system, and observing the wide-spread and 
 varying delicacy of the sense, he was led to suppose 
 that it might either be diffused, so to speak, as several 
 organs, over the body, or be somehow identified with 
 or included in the flesh which covers the body. l The 
 flesh is the muscular substance, and as it envelopes, so 
 to say, the body, it was probably supposed to be the 
 seat or cause of the sense, as every part is sensible to 
 Touch; and the analogue of flesh is the colourless sub- 
 stance of the Insanguinea insects, <tc. *And there 
 is a close analogy between the two substances, "as 
 the muscles of the highest class of animals, during 
 their development pass through the soft, colourless, 
 
 1 De Partib. Aid. i. 8. i. 3. 
 
 3 Grant's Outlines of Comp. Anat.
 
 118 PEELUDE TO CHAP. XI. [BK. II. 
 
 homogeneous and gelatinous condition of the Inverte- 
 brata, before assuming the red colour." As the 
 Touch, besides, was regarded as the first in order of 
 the senses and characteristic of animals, so the flesh 
 was said to be the origin of all other parts of animal 
 bodies, bone and skin, sinews, veins, hair and nails ; 
 and this hypothesis may have confirmed the opinion 
 that it is either the sense or the seat of the sense of 
 Touch. 
 
 CHAPTER XI. 
 
 THE same reasoning holds good for the tangible 
 quality as for the Touch ; for if the Touch be not a 
 single but a manifold sense, it follows that tangible 
 qualities must be manifold also. Now, it is difficult 
 to determine whether the Touch is a manifold or a 
 single sense, and difficult also to say what the organ 
 may be which is percipient of tangible qualities ; that 
 is, whether or not it is the flesh, and that which, in 
 other creatures, is analogous to flesh; but yet the 
 flesh is only the medium, and the essential organ, 
 therefore, must be something different from flesh, and 
 situated internally. 
 
 Each sense seems to be perceptive of only one 
 contrary, as Sight of white and black, Hearing of
 
 CH. XI.] ARISTOTLE ON THE VITAL PRINCIPLE. 119 
 
 acute and grave, and Taste of bitter and sweet ; but 
 several contraries belong to the sense of Touch, as hot 
 and cold, wet and dry, hard and soft, with others. 
 There is, it is true, a kind of solution for this diffi- 
 culty, in that the other senses also admit of several 
 contraries; as in the voice there are not only the 
 acute and grave but also the strong and weak, the 
 rough and smooth, with yet other contrasts; and 
 there are many and varied shades of colour. Still it 
 is not clear what that subjacent something is, which 
 is to the tangible impression what the Hearing is 
 to Sound. 
 
 Is then the sentient organ placed or not within 
 the flesh, or is it the flesh itself which is immediately 
 perceptive? It does not appear that any indication 
 can be obtained upon this point from sensation being 
 simultaneous with the tangible impression ; for, situ- 
 ated as we are, were any one to extend a membrane- 
 like substance over his flesh, the party would be 
 equally sensible when touched, and sensible at the 
 moment of contact; and yet, clearly, the sentient 
 organ cannot be in that membrane. It may be, how- 
 ever, that if the membrane were a congenital part of 
 the body, sensation would pass through it more 
 rapidly. Thus, this part of the body appears to be 
 disposed towards us as air would be, had air been 
 diffused around us ; for it would seem to us as thougli 
 by some one sense we perceive sound, colour, and
 
 120 ARISTOTLE ON THE [BK. II. 
 
 odour, and as though sight, hearing, and smell, are 
 one and the same sense. But now, as the motions 
 emanating from external objects are distinguishable 
 by the medium through which they are conveyed, 
 the sentient organs alluded to must manifestly be dif- 
 ferent also. With respect to the Touch, however, 
 this is still obscure, for it is impossible that a 
 living body should be constituted out of air or water, 
 as it must have some solidity; and there remains 
 only this conclusion, that it must be a mixture of 
 earth, and such other particles as have affinity with 
 flesh, and the analogue of flesh. Thus, the body has, 
 of necessity, been adapted for being the medium for 
 the tangible sense, through which the several tangi- 
 ble impressions are to be conveyed; and that the 
 impressions are manifold is shewn in the tongue 
 being perceptive of tangible as well as sapid qualities. 
 We are sensible, in fact, by this organ of all tangible 
 as well as sapid qualities ; and were the rest of the 
 flesh, like the tongue, sensible of savour, then " Taste" 
 and " Touch" would seem to be one and the same 
 sense ; but now we perceive, since they are not con- 
 vertible, that they must be distinct senses. 
 
 It may be a question whether, as all bodies have 
 depth, that is the third magnitude, any two bodies, 
 which have between them another body, can be in 
 contact ; for neither the humid nor the liquid is incor- 
 poreal, as each must, of necessity, be water or hold
 
 CH. XI.] VITAL PRINCIPLE. 121 
 
 water ; and thus, it follows that, as the extreme parts 
 of bodies in the water are not dry, the water, with 
 which their extremities are covered, must be inter- 
 posed between them. If this be true, then it is im- 
 possible that one body, when in the water, should be 
 in immediate contact with another; and this holds 
 good for bodies in the air ; for the air is in the same 
 relation to bodies in air which water is to bodies in 
 water ; but owing to our being in the air, the fact as 
 readily escapes us, as it does aquatic animals, from 
 their being in water, that water is in immediate 
 contact with water. It may then be asked whether 
 there is but one mode of impression for all the senses, 
 or whether it is different for different senses, seeing 
 that taste and touch are acted upon by contact, and 
 the other senses from a distance ? But yet this is a 
 seeming difference only, for we perceive the hard and 
 the soft, as we do the odorous, the sonorous, and the 
 visible, through media ; with this difference, that the 
 former impressions are made by objects close to, and 
 the latter by objects at a distance from us. On which 
 account, as we perceive all things through a medium, 
 the medium, in the case of bodies close to us, escapes 
 our attention; but if, as we have already said, we 
 could be sensible of all tangible impressions through 
 a membraneous substance, without our being con- 
 scious of their having been so transmitted, we should 
 then be situated as we now are, when in water or air;
 
 122 ARISTOTLE ON THE [BK. II. 
 
 for so situated, we seem to touch bodies directly, and 
 to have no impression from them through a medium. 
 
 But tangible differ from visible and sonorous im- 
 pressions, in that the latter are perceived by the me- 
 dium acting in some way upon us, while the former 
 are perceived, not by, but together with, the medium, 
 like a man who is struck through his shield ; for it 
 is not the shield which, having been struck, strikes 
 him, but the shield and he are simultaneously struck 
 together. To use a general expression, the flesh and 
 the tongue seem to be in the same relation to the 
 touch which air and water are to sight, hearing, and 
 smell ; are disposed towards that organ, that is, as 
 each of those elements is to each of those senses. 
 When the sentient organ itself is touched, no sensa- 
 tion can there or then be produced, any more than a 
 white object can be seen when placed immediately 
 over the surface of the eye; and thus it is evident 
 that the part perceptive of tangible impressions must 
 be within. Thus, it should be with the touch, as 
 with the other senses; and if objects, when placed upon 
 an organ, are not perceived, but, when placed upon the 
 flesh, they are perceived, we must conclude that the 
 flesh is only the medium for tangible impressions. 
 
 The distinctions of the body, as body, are tangible 
 distinctions, and by these I mean distinctions such as 
 distinguish the elements, as hot, cold, dry and moist, 
 upon which we have heretofore spoken in our treatise
 
 CH. XI.] VITAL PRINCIPLE. 123 
 
 upon the Elements. The organ which perceives those 
 distinctions is that of Touch ; and the part in which 
 resides, primarily, the so-called sense of Touch is, in 
 potentiality, what tangible impressions are in re- 
 ality; for all sensation is a kind of impression. So 
 that whatever, by its agency, makes something else to 
 be as itself, can do so only from that something being 
 already, as itself, in potentiality. Hence, we are not 
 sensible of hot and cold, hard and soft, when mani- 
 fested in the same degree as in ourselves, but perceive 
 them only when in excess, as if the sensibility were 
 some kind of mean between the contraries of sentient 
 impressions, and able, as such, to judge of sentient 
 perceptions. The mean, in fact, is critical for it is 
 either of the extremes in its relation to the other; 
 and as that which is to perceive white and black may 
 be neither one nor the other actually, and yet both 
 potentially, so it is with the other senses, and with 
 touch, which may be neither hot nor cold. 
 
 As vision was said to be, in some sense, perceptive 
 of the visible and the invisible, and the other senses 
 equally of their opposites, so Touch may be said to be 
 perceptive of the tangible and the intangible ; and by 
 intangible is meant as well what differs but slightly 
 from what is tangible, as air for instance, as what is 
 in such excess as to be destructive of all sensation. 
 
 We have thus then spoken, although but super- 
 ficially, upon each of the senses.
 
 PKELUDE TO CHAP. XII. 
 
 HAVING treated of each of the senses, Aristotle here 
 proceeds to consider the source of sensation, the 
 sensibility, that is, which is typified as plastic wax, 
 from its capability of receiving the form of an object 
 without its matter. This comparison is indeed a 
 happy one ; and it has been often employed by 
 writers in modern times, and "among others by 
 Bossuet 1 ." The chapter shews that for perception 
 there must be a due relation between impression and 
 sense, and that plants are insentient because they 
 have no faculty for the reception of the forms of 
 objects ; and it concludes by shewing that the agency 
 of some properties, as light, sound, <kc., is confined 
 to the sentient organs. 
 
 1 Connoissance de Dieu.
 
 CHAPTER XII. 
 
 IT must be admitted, for the senses in general, that 
 each one is receptive of the perceptible forms of 
 things without the matter, as wax takes the impress 
 from a seal-ring, without the iron or gold of which 
 the ring is made ; takes the device, that is, without 
 the metal on which the device is inscribed. In like 
 manner, the sense is impressed by each object having 
 colour, or savour, or sound ; not, however, after the 
 appellation of the object but, according as it is of a 
 certain quality, and in a given relation to the sense. 
 It is the primal organ in which this faculty exists ; 
 and it is identical with the object perceived, although 
 different from it in mode of being ; for, otherwise, the 
 percipient would be some kind of magnitude. But it 
 cannot belong either to that percipient or to sensation 
 to be magnitude, as they are rather a relation to, and 
 a faculty for the perception of the qualities of each 
 object. Thus, it is, from these reasons, made manifest 
 why sentient impressions in excess destroy the sen- 
 tient organs ; for if the motion of the impression be 
 stronger than that of the organ, then the relation
 
 126 ARISTOTLE ON THE [l3K. II. 
 
 which constitutes sensation is dissolved, as harmony 
 and tone become discordant, when the chords are 
 struck too forcibly. 
 
 But why do not plants feel, seeing that they also 
 possess a living part, and are impressionable by tan- 
 gible qualities ? And that they are so impressionable 
 is shewn in their being both cooled and heated ; but 
 the cause is that they have not that mediate faculty, 
 nor any such principle as admits of their receiving 
 only the forms of things ; that along with forms they 
 are affected by the matter also. 
 
 It may be questioned whether impressions can be 
 made by odour upon what may be without smell, or 
 by colour upon what may be without vision, and so 
 for other qualities and senses. But if that which is 
 smelt be odour, then odour, if it produce anything, 
 must produce smell, and thus nothing without smell 
 can be affected by odour, and the same holds good 
 for the other senses; neither can beings which are 
 sentient be affected, save in so far as they are sen- 
 tient. All which is made evident in that neither 
 light nor darkness, sound nor odour, can act upon 
 bodies, although that which is present with them 
 may, as air with thunder splits wood. But yet tan- 
 gible and sapid qualities do act upon bodies; for, 
 otherwise, by what could inanimate things be acted 
 upon and changed ? Shall it then be said that those 
 other qualities also act upon bodies ? But all bodies
 
 CH. XII.] VITAL PRINCIPLE. 127 
 
 are not impressionable by odour and sound, and those 
 which are so are indefinite and mobile, such as is the 
 air ; for the air gives out odour, as if it had been sub- 
 ject to impression. What then is smell but impres- 
 sion of some kind? But smelling is a sentient per- 
 ception ; and the air having been impressed by odour, 
 becomes quickly sensible to us.
 
 PRELUDE TO CHAPTER I. 
 
 'Tms book has been by one commentator held to be 
 spurious, even while admitting that all the opinions 
 are genuine, because of imputed solecisms in the 
 style and phraseology, which seem to indicate a 
 foreign hand. But were any one capable, as Tren- 
 dellenburg observes, of adopting, with so much per- 
 spicacity, the reasoning of Aristotle, he would be 
 much rather inclined to put forth an original work, 
 than thus to shelter his productions under another's 
 name. The opening passages involve great, it may 
 be, insuperable difficulties, owing rather to the argu- 
 ment than to the wording, although this is obscure, 
 for it seems to be assumed that a sense would be felt 
 to be wanting, although it might never have been 
 possessed ; and that the consciousness of its privation 
 would prove whether or not a sense were wanting. 
 
 According to this theory, in fact, if the Touch were 
 a sense for every impression of which we now are 
 1 Vide Trendell. Comment.
 
 PRELUDE TO CHAP. I. 129 
 
 sensible, and if there were any property not percep- 
 tible by us, we should perceive that another sentient 
 organ was required ; but it has not been shewn that 
 such a want, had it not previously been satisfied, 
 could be made sensible to us. And even for the 
 Touch itself, were there any one property, of which 
 we are sensible, say that of hardness, which had 
 never been perceived, we could hardly be conscious 
 of the want ; and there may be, probably are pro- 
 perties in the bodies around and above us of which 
 we are unconscious, and yet remain without the feel- 
 ing of a want. Each of the senses seems to be an 
 ultimate fact ; for we are satisfied that we see by 
 the eye and hear by the ear, and that with so little 
 attention or will that the sentient organs perform 
 their part almost irrespectively of the percipient. 
 In the succeeding passages, which relate to media 
 and the elementary constitution of the senses, there 
 is ambiguity or confusion, occasioned by the then 
 prevailing dogmata of dements and like by like, and 
 perhaps, it may be added, by unacquaintance with 
 the structure of the sentient organs.
 
 BOOK THE THIRD. 
 
 CHAPTER I. 
 
 WE may be satisfied, from the observations which 
 follow, that there is no sense besides the five be- 
 sides, that is, Sight, Hearing, Smell, Taste, and 
 Touch ; for if Touch be the sense for every impression 
 of which we are sensible, and if we have this sense, 
 then, as all the conditions of whatever is tangible, in 
 so far as tangible, are made perceptible to us by the 
 Touch, it follows that, if any sensation be wanting, 
 some sentient organ must be wanting to us also. 
 Now, all the bodies which are perceived by touch- 
 ing are made sensible to us by the Touch which has 
 been allotted to us ; and all those which are perceived, 
 not by touching but, through media, are made sensi- 
 ble to us by simple bodies that is, by air and water. 
 We are so constituted, in fact, that, if several objects, 
 differing generically from one another, could be per- 
 ceived through one medium, an individual, having a 
 sentient organ such as that medium, would, neces-
 
 CH. I.] ARISTOTLE ON THE VITAL PRINCIPLE. 131 
 
 sarily, be sensible of impressions through both me- 
 dia as if the sentient organ should be of air, then, as 
 air is the medium for sound and colour, the individual 
 would be sensible of both impressions through the 
 same organ. Should there, however, be more than 
 one medium for the transmission of the same impres- 
 sion, as air as well as water (since both are diapha- 
 nous,) serves for the transmission of colour, then an 
 individual, having an organ constituted of either of 
 those elements, would perceive impressions transmit- 
 ted through them both. The sentient organs, how- 
 ever, are constituted of those two simple bodies, air 
 and water, exclusively for the pupil is of water, the 
 hearing of air, and the smell either of one or other ; 
 but fire forms no part of any organ, or rather it is an 
 element common to all, as there is nothing sentient 
 without heat ; and earth either does not enter at all 
 into any sentient part, or it has been in some especial 
 and peculiar manner combined with the Touch. 
 Thus, there can remain only this conclusion, that, 
 were there no air or water, there could be no sentient 
 organ; and organs so constituted are actually pos- 
 sessed by animals now living. All the senses, in fact, 
 are possessed by animals which are neither imperfect 
 nor mutilated ; for the mole appears to have eyes be- 
 neath its skin. So that, unless there is some kind of 
 body hitherto unknown and some kind of impression 
 unsuited to bodies here on earth, it may be affirmed 
 
 92
 
 132 ARISTOTLE ON THE [BK. III. 
 
 that no sense can be wanting to us. But neither is it 
 possible that there should be any special organ for 
 the perception of common properties, (such as motion, 
 rest, magnitude, form, number and unity), of which 
 we are made sensible, by each special sense, acci- 
 dentally ; for we perceive all such by motion as we do 
 magnitude, and as we do form, as form is a kind of 
 magnitude ; the state of rest we are sensible of by the 
 absence of motion, and number we perceive by the 
 want of continuity and by particular senses, for each 
 sense is perceptive of unity. So that, evidently, there 
 cannot be a peculiar sense for the perception of any 
 one of those properties, as motion, for instance ; with 
 respect to which we shall be ever situated as we now 
 are, when, by sight, we judge of something sweet. 
 And this we are able to do from our happening to 
 possess a sense which is perceptive of double impres- 
 sions, and by the way in which those impressions 
 coincide, we recognise what the thing is ; were this 
 not the case, then, in no wise, except by chance, 
 could we perceive that the thing was sweet, any 
 more than we could tell that an individual is the son 
 of Cleon, not because he is really so, but because he 
 is fair ; and fairness is an accident pertaining to the 
 son of Cleon. And yet we have a common sense for 
 the perception of common properties and that not 
 casually, although it is not a peculiar sense ; for, were 
 it so, then in no otherwise could we perceive those
 
 CH. I.] VITAL PRINCIPLE. 133 
 
 properties than, as has just been said, we see that an 
 individual is the son of Cleon. The senses, however, 
 do perceive, casually, the special qualities of each 
 other ; but then they do so, not as distinct senses but, 
 as becoming one sense, as when double impressions 
 may be made simultaneously upon the same organ, 
 as by bile, which is bitter and yellow. But as it 
 belongs not to either sense to say that both qualities 
 belong to one substance, we are exposed to error, and 
 led to think that if a fluid be yellow it must be bile. 
 
 Should any one inquire why we have been fur- 
 nished with several senses in place of having only 
 one, it might be answered, " that we have so been 
 constituted in order that the sequences and common 
 properties of bodies, as motion, magnitude, and num- 
 ber, may the less readily escape our notice." If 
 vision, in fact, were our only sense and it perceptive 
 only of whiteness, then all other qualities would more 
 readily escape our notice and seem to be identical, on 
 account of colour and magnitude being in an invariable 
 sequence to one another. But as here common proper- 
 ties are manifested in different bodies, it is evident that 
 each of those properties (colour and magnitude) must 
 also be different.
 
 
 PRELUDE TO CHAPTER II. 
 
 THIS chapter opens with a continuation of the discussion 
 upon the senses, and, assuming sensation to be an 
 ultimate fact, it argues that vision (taken as an ex- 
 ample), must be the office of the eye, or some other 
 sense; if the office of some other sense, then it, 
 unlike every other, will have had assigned to it two 
 different modes of impression. Add to this, that 
 like the visual sense, which perceives colour only, it 
 must be imbued with colour, and this would inter- 
 fere with its own peculiar office. The further objec- 
 tion to another than its own sense for vision, in its 
 requiring an infinite series of perceptions, is neither 
 clear nor apposite ; for, had a sense been made per- 
 ceptive of double impressions, that faculty would be, 
 as much as a single sense, an ultimate fact. The 
 passage has been a fruitful topic for commentators, 
 as might be supposed, but it still remains the subject 
 of conjecture.
 
 CHAPTER II. 
 
 SINCE we are sensible that we see and hear, we cannot 
 but be sensible that we see by sight or by some 
 other sense ; but, if we see by some other sense, then 
 it will be perceptive of sight and colour, the subject 
 of sight ; and thus there will be either two senses for 
 the same office, or the sight itself will be the percipient. 
 If, besides, there is some other than the visual sense 
 for sight, we shall have to admit an infinite series of 
 perceptions, or else this other sense, whatever it may 
 be, will be the visual percipient ; and this might as 
 well have been conceded to the first sense. But here 
 there is a difficulty if to perceive by sight is seeing, 
 and if that which is seen is colour or something 
 having colour, then, if any sense is to see that which 
 sees, that sense must first have colour. It is then 
 manifest that perception by sight is not a single per- 
 ception ; for even when we may not see, it is still by 
 sight that we judge both of darkness and light, al- 
 though not in the same manner. That, moreover, which 
 sees, must have been already imbued with colour, since 
 each sentient organ must be receptive of the object of
 
 136 ARISTOTLE ON THE [BK. III. 
 
 perception without its matter ; and this accounts for 
 impressions and images being still present in the sen- 
 tient organs, after objects have been withdrawn. 
 
 The action of the object of perception is one and 
 the same with that of the sense, although they differ 
 in mode of being I mean, for example, sound in 
 action and hearing in action ; for it may be that an 
 individual, endowed with hearing, does not hear, as 
 that a sonorous body does not give out sound. But 
 when an individual, capable of hearing, listens, and 
 when that which is sonorous gives out sound, then 
 hearing in action coincides with sound in action, and 
 the one may strictly be termed hearing, the other 
 sound. If motion, production, and impression, are in 
 the product, it follows that sound and hearing, in an 
 active state, must pre-exist in hearing in a potential 
 state; for the action of the creative and the motive 
 exists, naturally, in that which is to be acted upon. 
 It is, therefore, no way necessary that the motor 
 should be itself in motion. The action, then, of the 
 sonorous body is sound or sounding, that of the audi- 
 tory sense is hearing or audition; for hearing is 
 double as sound is double, and the same applies to 
 other senses and perceptions. Since production and 
 impression are, not in that which acts but, in that 
 which is impressed, so the action of the object of per- 
 ception and the sensibility is in the sentient being. 
 But, while for some senses these two states have
 
 CH. II.] VITAL PRINCIPLE. 137 
 
 been specially distinguished by names, as sound and 
 hearing, there are others for which one or other state 
 is without appellation the action of vision, for in- 
 stance, is called sight, but the action of colour is 
 unnamed ; the action of the sapid sense is called taste, 
 while that of savour is without appellation. 
 
 Since the action of the object of perception and 
 that of the sentient being is one and the same, 
 although different in mode of acting, it follows that 
 hearing and sound, in this sense, must together be lost, 
 or together be preserved; and this is true of taste 
 and savour, and other senses and functions ; but yet it 
 does not hold good of those relations in potentiality. 
 
 The earlier physiologists have expressed them- 
 selves ill upon the subject, as they thought that there 
 can be neither black nor white without sight, nor 
 savour without Taste. And yet what they said was 
 in part right and in part wrong; for as senses and 
 sentient impressions have a twofold acceptation, ac- 
 cording to their state of potentiality or activity, so 
 what was advanced by them may be applicable to 
 the one state, and inapplicable to the other. The fact 
 is, those writers reasoned absolutely upon conditions, 
 which do not admit of being so dealt with. If a voice 
 of any kind is harmony, and if voice and hearing are, 
 in one sense, the same, and, in another sense, not the 
 same, then, as harmony is proportion, it follows that 
 hearing must be proportion also. And hence it comes
 
 138 ABISTOTLE ON THE [BK. III. 
 
 that every sound in excess, whether acute or grave, 
 perverts the hearing, as every savour in excess does 
 the taste ; and every colour over-bright or dark dulls 
 the sight, as every odour excessively pungent, whether 
 grateful or offensive, does the smell, as if shewing 
 that sensibility is a kind of proportion. Thus, quali- 
 ties, as acid or sweet or saline, are agreeable when- 
 ever they are reduced, pure and unmixed, to a due 
 proportion ; for it is this only which renders them 
 grateful. To speak generally, harmony is a combi- 
 nation of tones rather than the acute or the grave 
 singly, as for the Touch, the warmed or cooled is 
 genial, rather than the hot or cold, simply; for, as 
 sensibility is proportion, so qualities, in excess, pain 
 or pervert the senses. 
 
 Each sense is perceptive of its own appointed 
 subjects, is innate in its own organ, as a opnal 
 organ, and judges of the distinctions of qualities, as 
 sight judges of white and black ; taste of bitter and 
 sweet, and so as to other senses and qualities. But 
 since we judge of white, sweet, and each other 
 quality by its relation to each sense, by what do we 
 perceive that qualities differ ? Now, it is evident that 
 it must be by some sense, as the impressions are all 
 sentient ; and equally so that the flesh cannot be that 
 final organism, as in order to judge of qualities it 
 must, of necessity, first touch bodies. Neither is it 
 admissible that, by different senses, we judge sweet
 
 CH. II.] VITAL PRINCIPLE. 139 
 
 to be different from white, as both qualities must be 
 apparent to some single faculty; for, otherwise, it would 
 be as if I should perceive one quality and you perceive 
 another, and thus make it evident that they are dif- 
 ferent from one another. But it is here required that 
 the same individual should perceive that they are 
 different, for the sweet is different from the white, 
 and what he perceives that he says ; and thus, what 
 he says that he thinks and perceives. It is then evi- 
 dent that we cannot, by different senses, judge of 
 different qualities, as also, from what follows, that we 
 cannot judge of them in a separate portion of time. 
 Neither can an opinion be in a separate portion of 
 time ; for just as it is the same individual who says 
 that good is other than bad, so when he says that the 
 one is different from the other, he implies that the 
 other is equally so, and does not employ the term 
 when loosely he does not use it, I mean, in the 
 sense of now, in the phrase, "now I say that the object 
 is different," without implying that it is different now. 
 But, here, it is the same individual who employs the 
 term now, and says that objects are different now and 
 because now; for the impressions are coincident, as 
 they are inseparable, and as the time is indivisible. It 
 cannot, however, be, that the same individual, in so 
 far as indivisible, should be subject to contrary im- 
 pulses in time which is indivisible ; yet if sweetness 
 move sensation or thought in one way, bitterness
 
 140 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 must move them in an opposite, and whiteness in 
 some other direction. Can, then, that which judges 
 be, numerically, indivisible and inseparable, yet sepa- 
 rable in its mode of being ? If so, then, in some way, 
 as divisible, it may perceive divisible, and, in some 
 way, as indivisible, it may perceive indivisible quali- 
 ties ; for in its mode of being it is separable, but, 
 locally and numerically, it is inseparable. But is not 
 this impossible ? The same may, in potentiality, be 
 indivisible and divisible and be the contraries; but 
 not so in mode of being, as it is divisible in action, 
 and cannot possibly be at once white and black, nor 
 be simultaneously impressed by the forms of those 
 colours, provided sensation and thought are such as 
 we have said they are. But it is with this, as with 
 that which some call a point, and which, in so far as 
 it is one or dual, is indivisible or divisible. Thus, in 
 so far as that which judges is one, it is indivisible, 
 and its perceptions are simultaneous ; and in so far as 
 it is divisible, it employs the same point twice, simul- 
 taneously. In so far, then, as it employs the boun- 
 dary as two, it judges of two things by it and per- 
 ceives that they are distinct, as the boundaries of the 
 line are distinct ; but in so far as it is one, it judges 
 by one act, and judges simultaneously. 
 
 Let what has been said then suffice for the defi- 
 nition of that principle, by which we maintain that 
 an animal is made a sentient being.
 
 PRELUDE TO CHAPTER III. 
 
 THIS chapter may be regarded as a metaphysical disquisi- 
 tion, since its purport is to distinguish mental facul- 
 ties from corporeal sensations as well as to examine 
 the opinions of earlier writers who had maintained 
 that cogitation is some kind of sensation; and, 
 finally, the nature of imagination, as lying inter- 
 mediately between faculties and sensations, is investi- 
 gated and defined. It treats, too, although but 
 incidentally, of the understanding, knowledge, opi- 
 nion, and other topics which border on abstractions ; 
 and closes with etymology to shew the sentient 
 origin of imagination.
 
 CHAPTER III. 
 
 As writers, for the most part, define Vital Principle 
 by two different faculties, by locomotion and thought, 
 judgment and sensibility, it would seem as though 
 thought and reflexion are by them considered to be 
 some kind of sensation ; for, in both cases, the Vital 
 Principle both discerns and recognises something. 
 Thus, the ancients affirm that reflexion is identical 
 with feeling; and Empedocles has said, "man's in- 
 telligence is enlarged by what is present," and, else- 
 where, " hence, man derives his power of reflecting 
 upon different subjects;" so Homer's words, "such is 
 the mind" do but express the same idea. All these 
 writers assume, in fact, that thinking, like feeling, is 
 corporeal, and that Like is perceived and compre- 
 hended by Like, as was explained in our opening 
 chapters. But yet it was incumbent upon them to 
 have spoken, at the same time, upon the liability to 
 error through the senses ; for this belongs, more pe- 
 culiarly, to animals, and Vital Principle remains sub- 
 ject to it during the greater portion of existence. On 
 which account, either all appearances are, as some of
 
 CH. III.] AEISTOTLE ON THE VITAL PRINCIPLE. 143 
 
 those writers maintain, necessarily, true, or else error 
 is caused by contact of the unlike, which is the oppo- 
 site of the opinion, that like is recognised by like; and 
 the error from contraries seems to be identical with 
 the knowledge of contraries. It is manifest that feel- 
 ing is not identical with reflexion; for, while the 
 former belongs to all creatures, the latter has been 
 imparted only to a few. Neither is thinking, that 
 faculty to which belongs the sense of right and wrong, 
 (the right comprehending judgment, knowledge, and 
 sound opinion, the wrong comprehending their con- 
 traries,) to be confounded with feeling for sensation, 
 being derived from particulars, is ever true, and 
 belongs to all animals; but the judgment may be 
 wrong, and is imparted only to such as have reason. 
 Imagination, in fact, is neither sensation nor judg- 
 ment, and yet it is not called up without sensation, 
 just as, without sensation, there can be no conception ; 
 but it is manifest that imagination is not conception. 
 Imagination depends, in fact, but upon ourselves, as we 
 can, at will, call it up (since it is in our own power 
 to place images before the eyes, as do they who, for 
 mnemonic aids, by laying down objects, form sym- 
 bols) ; but to form an opinion does not depend upon 
 ourselves, and then every opinion is, of necessity, 
 either true or false. Whenever, besides, we may have 
 an opinion upon any terrible and fearful incident, we 
 are straightway affected as if it were a reality, just as
 
 144 ARISTOTLE ON THE [BK. III. 
 
 we are when we think upon any desperate deed ; but, 
 under imagination, we become simple spectators, as it 
 were, of a pictorial representation of terrible or daring 
 achievements. There are, in conception itself, the 
 distinctions of knowledge, opinion, reflexion, and their 
 contraries, of which we shall speak elsewhere. With 
 respect to thinking, since it is different from feeling, 
 and feeling seems, in part, to be imagination and, in 
 part, conception, let us here define imagination, and 
 then proceed to the consideration of the other faculty. 
 
 If imagination be a faculty by which we say that 
 an image of some kind, and that not merely in the 
 sense of a metaphor, is called up within us, then it is 
 to be ranged among those faculties or powers, such as 
 feeling, opinion, knowledge, mind, by which we form 
 judgments and determine what may be true or false. 
 
 It is clear from what follows, that imagination is 
 not sensation ; for sensation is either a faculty or an 
 act, such as sight, and seeing, but an image is some- 
 times apparent to us without either faculty or act, as 
 phantoms in dreams for instance ; and then sensation 
 is ever present, which is not the case with the imagi- 
 nation. If, moreover, imagination were in act identical 
 with sensation, we should have to admit that it must 
 belong to all irrational creatures, but this does not seem 
 to be the case with the ant, bee, or worm; and then 
 sensations are always true, but imaginings are for the 
 most part false. Hence, we do not say, when accurately
 
 CH. III.] VITAL PRINCIPLE. 145 
 
 examining any object, that we imagine to be so or 
 so, a man for instance, but we so express ourselves 
 rather when we do not clearly perceive what the 
 object is, and when the perception may be true or 
 false; when, to use a former expression, the object 
 appears to us as landscapes do to the purblind. 
 
 Neither can imagination be regarded as one ot 
 those faculties, such as knowledge and mind, which are 
 always true, for it admits of being false as well ; and 
 it remains for us to consider whether it is opinion, 
 since opinion may be both true and false. But belief 
 follows upon opinion, (as it is not admissible that an 
 individual should not believe in that upon which he 
 has an opinion,) and belief belongs to no irrational 
 creature although imagination is imparted to many. 
 Belief, besides, is an attendant upon every opinion, 
 as persuasion is upon belief, and reason alone can 
 persuade ; but although imagination belongs to some 
 irrational creatures, reason has been given to none. 
 It is manifest, then, that imagination can neither be 
 opinion with or through sensation, nor a combination 
 of opinion with sensation ; and for the same reasons 
 evident, that opinion is from nothing else but that 
 from which sensation is derived. By which I mean, 
 if imagination be the combination of an opinion of 
 whiteness and a sensation of whiteness, and not of an 
 opinion of goodness with a sensation of whiteness, then 
 to imagine is to think upon what has been sensually ' 
 
 10
 
 146 ARISTOTLE ON THE [BK. III. 
 
 perceived, and that not accidentally. But there are 
 appearances which are fallacious, although our concep- 
 tion of them at the time may be true, as the sun, for 
 instance, appears to be a foot in diameter, and yet we 
 are satisfied that it is larger than the earth ; and in 
 such a case it happens either that the true opinion of 
 the sun's dimension must have been cast aside, or 
 else, while the sun remains as it was and the true 
 opinion has neither been forgotten nor changed, that 
 the opinion is at once both true and false. But the 
 opinion is simply false when it escapes us that the 
 thing seen is altered. It is evident, then, that ima- 
 gination can neither be any one, nor be derived from 
 any one of those faculties. 
 
 Since one object having been set in motion can 
 communicate motion to another, and since imagination 
 seems to be a kind of motion, and never to be produced 
 without sensation, or in other than sentient creatures, 
 or without the objects of sentient perception, and since, 
 on the other hand, motion can be produced by the act 
 of sensation, and this motion must of necessity be 
 equal to the impression, it may be admitted that the 
 motion of imagination can neither be produced with- 
 out sensation, nor in other than sentient beings ; that 
 beings endowed with it act and are acted upon in 
 many ways, and that its manifestations are both true 
 and false. This latter alternative happens thus: the 
 sensation which is derived from the objects peculiar
 
 CH. III.] VITAL PRINCIPLE. 147 
 
 to each sense is true, or it involves the smallest 
 amount of error ; but when, in the second place, such 
 objects are perceived in their accidents, there is room 
 for fallacy; when for instance, something is said to 
 be white, there is no fallacy, but when that object is 
 particularised and said to be this or that, the percep- 
 tion may be fallacious. There is, in the third place, 
 liability to error in our perception of common proper- 
 ties, and sequences in the accidents referrible to parti- 
 cular bodies accidents, I mean, such as motion and 
 magnitude, which are referrible to all bodies, and 
 from which there is peculiar liability to error through 
 the senses. But the motion produced by the act of sen- 
 sation will differ from the sensation derived from these 
 three modes of sensation the first, while sensation is 
 yet present, must be true; but the others, whether sen- 
 sation be present or not, may be fallacious, and more 
 especially, when the objects causative of sensation may 
 have been withdrawn. If, then, imagination alone 
 fulfil all the conditions indicated, and if it be all that 
 has been said, it may be defined as motion produced 
 by sensation in action. And since vision is a sense 
 above all others, imagination has derived its appella- 
 tion from light, because without light there is no 
 vision; and owing to its being an abiding faculty 
 and like sensations, animals perform many of their 
 actions through it. Some animals are so influenced from 
 being irrational; and others, as man, from having 
 
 102
 
 148 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 their understanding eclipsed, at times, by passion, 
 disorder, or sleep. 
 
 Let this much, however, suffice for the inquiry 
 into imagination, for shewing what it is, and for what 
 purposes it has been imparted.
 
 PRELUDE TO CHAPTER IV. 
 
 THIS chapter is upon the mind (o uous) and Aristotle's 
 inquiry is, whether it is part of that principle which 
 gives life to the body, or altogether distinct from 
 corporeal relations. It seems to be at once deter- 
 mined that there is no affinity between the mind 
 and sensibility, the ministrations of which trench so 
 closely upon cogitation ; and that the mind, there- 
 fore, existing independently of the body, is related to 
 subjects of thought, abstractions that is, as is sensi- 
 bility to sensism and sensation. Anaxagoras re- 
 garded all things as combinations save mind, which 
 alone he held to be homogeneous and pure. Aris- 
 totle 1 makes the mind to be receptive of the subject, 
 and the essence of the subject of thought ; to be 
 something divine, and to confer upon us contempla- 
 tion, which is our sweetest, best enjoyment. " If this 
 faculty, in its occasional exercise, as by ourselves, is 
 happiness, it is, as the eternal attribute of the Deity, 
 
 1 Metaphys. I. 8, 13 ; XI. 7, 8 ; I. 3, 10 ; m. 5, 12.
 
 150 PRELUDE TO CHAP. IV. 
 
 wonderful, and more wonderful in proportion as 
 more enduring." But yet Aristotle quotes, without 
 objection, that the mind is innate in animals., and 
 the cause, in nature, of the world and its order ; and 
 he cites the verses of Parmenides, which seem to 
 imply that the mind is present in the limbs of man 
 as if it were a corporeal agent. To judge, however, 
 from observations in the course of this treatise, he 
 may be said, although, perhaps, not always consist- 
 ently, to have considered this great principle as 
 impassive, indiscerptible, and freed from all corporeal 
 ties ; and as being itself, only when withdrawn from 
 matter and its influences. Thus, as matter must 
 tend to preclude its offices, its existence, while asso- 
 ciated with mortal beings, can be only that of poten- 
 tiality.
 
 CHAPTEK IV. 
 
 WITH respect to the part of Vital Principle by which 
 it both knows and reflects, whether that part be sepa- 
 rate, or separate, not substantively but, in an abstract 
 sense only, let us now consider in what it is distin- 
 guished from other parts, and how thinking is at any 
 time exercised. If thinking be such as is feeling, 
 then it may be some kind of impression by the subject 
 of thought, or other analogous agency. But then 
 that which thinks must be impassive, receptive of the 
 form of objects, and, in potentiality, the same as the 
 object, without actually being so. The mind, in fine, 
 must be related to subjects of thought as the sensi- 
 bility is to objects of perception. It is, then, necessary 
 since the mind thinks upon all subjects, that it should 
 be homogeneous, in order, as Anaxagoras expresses 
 himself, that it should domine, that is, recognise 
 things ; and as whatever is foreign to it precludes 
 and eclipses its inward light, so it can have no other 
 nature than that of potentiality. Thus, the so-called 
 mind of Vital Principle (and by mind I mean that part 
 by which Vital Principle judges and compares), is 
 not actually any one of the subjects of thought before
 
 152 ARISTOTLE ON THE [BK. III. 
 
 thinking upon it. It is very improbable, therefore, 
 that the mind should have been commingled with the 
 body; for were this the case, it would be a quality of 
 some kind, as hot or cold, or it would have some kind 
 of organ as there is for the sensibility, but no such 
 organ is to be found. It is well said by some that 
 Vital Principle is the place of forms, only this is to 
 be understood of Vital Principle, not as a whole but 
 as a cogitative faculty, and of forms, not in reality 
 but, in potentiality. 
 
 It is manifest, from the nature of the sentient 
 organs and sensation, that the quiescent state of the 
 sentient is not the same as that of the cogitative part. 
 For the sensibility is unable to distinguish impressions 
 in excess, as a sound amid loud sounds, or a colour or 
 odour among brilliant colours or pungent odours, but 
 the mind, on the contrary, when thinking intensely 
 upon any subject, can still think and with increased 
 rather than diminished intensity upon the subordinate 
 details ; the sensibility, besides, cannot be without a 
 body, but the mind is separable. When thus situated, 
 the mind can become each of the subjects of thought, 
 as an individual is said to be learned actually (and 
 this may be said when he is able at will to employ 
 his learning,) because he is at the same time equally 
 learned in potentiality, although not as he was before 
 he had learned or invented something ; for when so 
 learned he is able to reflect upon his learning.
 
 CH. IV.] VITAL PRINCIPLE. 153 
 
 There is a distinction between positive magnitude 
 and ideal magnitude, water and ideal water, and so 
 between many but yet not all substances, as with 
 some the two states are identical, but the mind judges 
 of flesh and ideal flesh either by some different faculty 
 or by being itself differently disposed ; for flesh cannot 
 be without matter, but, as is a snub nose, it is some- 
 thing in something. Now, it is by the sensibility 
 that we judge of hot and cold and other properties of 
 which flesh is the standard ; but it is either by some 
 distinct faculty or as a curved is to an extended line, 
 that we judge of ideal flesh. Straightness, on the 
 other hand, as well as the snub nose we place among 
 abstractions, for each is associated with continuity; 
 but the difference, if there be a difference, between 
 positive straightness and ideal straightness, the mind 
 judges of by some other, perhaps a dual faculty ; 
 by some other faculty, at least, or by being itself 
 differently disposed. To use a general expression, 
 as are things abstracted from matter so are subjects 
 of thought with respect to the mind. 
 
 It is difficult to determine how the mind, if it be 
 as Anaxagoras supposes, homogeneous, impassive 
 and without any thing in common with aught else, 
 is to think, if thinking be some kind of impression ; 
 for it is only in so far as there is something in com- 
 mon between two substances, that the one seems to 
 act and the other to be acted upon. And there is
 
 154 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 the same difficulty if the mind itself is intelligible ; 
 for it will be present in other things, unless it is 
 itself, intelligible in some other way than they are, 
 and unless the subject of thought is some one 
 specific subject ; or else the mind will be some 
 kind of combination, and this reduces thought to the 
 nature of other things. But to suffer impression 
 according to some common relation implies, as has 
 been just explained, that the mind, in potentiality, is 
 as the subjects thought upon, and yet that, in reality, 
 it is no one of them before thinking upon it; and 
 thus the mind is to be regarded as a tablet on which 
 nothing may have been actually inscribed. The mind 
 is a subject of thought to itself as is any other topic, 
 since that which thinks and the subject of thought 
 are among immaterialities ; for speculative knowledge 
 is the same as the subject which is so known. But 
 we have to consider why the mind is not always 
 thinking, as each subject of thought, in potentiality, 
 is among materialities ; so that the mind will not be 
 present in any one of them (for the mind is the 
 immaterial faculty which judges of them), although 
 each of them will be subject to the mind.
 
 PRELUDE TO CHAPTER V. 
 
 THIS chapter assumes the existence of a generic matter, 
 as well as something which is to give to it reality, 
 and thus it seems to admit of formative conditions 
 other than those assigned to Vital Principle ; the 
 mind too, although said to be immaterial, is likened 
 to a material agent. Aristotle 1 elsewhere, somewhat 
 in conformity with this, says, "even granting that 
 all things may be from one, or more than one primal 
 element, and that the self-same matter may be the 
 source of all beings, yet there is a peculiar matter 
 for each genus, as pituita is the primal matter for 
 sweet and oily, as the matter of bile is for bitter and 
 analogous qualities." An early commentator observes, 
 "matter is the receptacle and subject of forms, 
 without having in itself either figure, quality, mag- 
 nitude, or place ; nevertheless, it is not a mere name, 
 but truly exists as the basis of qualities. Matter 
 
 1 Metaphys. vu. 4. i.
 
 156 PRELUDE TO CHAP. V. [BK. III. 
 
 exists potentially, bodies actually, with their peculiar 
 character ; and matter cannot be separated from 
 form and real existence." 
 
 CHAPTER V. 
 
 SINCE, throughout all nature, there is a matter for 
 each genus of entities (that which all belonging to 
 that genus are in potentiality), and a something which 
 is causative and constitutive from its making things 
 what they are, as art impresses its forms upon matter, 
 so those same distinctions must, of necessity, co-exist 
 in the vital principle. Such also is the mind, from 
 its faculty, on the one hand, of becoming all things, 
 and, on the other, of creating all things, as if it were 
 a virtuality like light ; for light, in a certain sense, 
 makes colours, being in potentiality, to become colours 
 in reality ; and the mind here meant is separate, im- 
 passive and homogeneous, being essentially an ener- 
 gizing influence. 
 
 That which acts is ever, in fact, more influential 
 than that which is acted upon, as the causative prin- 
 ciple is than the matter. Now, knowledge in activity 
 is identical with the subject ; but knowledge in poten- 
 tiality pre-exists in the individual ; and yet, strictly
 
 CH. V.] ARISTOTLE ON THE VITAL PRINCIPLE. 157 
 
 speaking, it does not pre-exist, as that cannot be said 
 to pre-exist which sometimes is, and sometimes is not 
 reflected on. But that alone, whatever it be, which 
 thinks, is separate from all else, immortal and eternal ; 
 and, because it is impassive, we derive from it no 
 memory. But the impressionable mind, on the con- 
 trary, is perishable ; and without it there can be no 
 cogitation.
 
 PRELUDE TO CHAPTER VI. 
 
 THIS chapter does but repeat what has already been 
 insisted upon, that the mind or the sensibility, when 
 engaged upon indivisibles, that is, single ideas or 
 simple sensations, is not subject to error ; and that 
 the liability to error commences when ideas or sensa- 
 tions are either generalized, or judged of in their 
 relations. It may be added, that the want of a 
 sensorium or faculty for the generalization of par- 
 ticular sensations, and for affording to the mind, 
 thereby, terms for comparison, is felt so much 
 throughout, that the brain alone can, for some 
 passages, fully explain all that the words may seem 
 to imply.
 
 CHAPTER VI. 
 
 WHENEVER cogitation is employed upon what may 
 be indivisible it is not subject to error, but when 
 engaged upon topics which involve both error and 
 truth, there is a simultaneous combination of thoughts, 
 whereby they are, so to say, individualized ; in the 
 way that Empedocles expressed himself, "Now the 
 heads of many creatures budded forth without necks, 
 and then, heads and necks were by affinity made one." 
 It is thus that thoughts, however disconnected, as 
 the incommensurable and the diameter, are by the 
 intelligence joined together. If the question relate 
 to things past or future, the mind, thinking upon 
 time besides, adds it to the other conditions; for 
 error lies ever in the combination, as when the white 
 is said not to be white, the error is in the addition of 
 the negative. Now, it is always in our power to 
 speak of things individually ; but then, it is not only 
 true or false that Clem is fair, but equally so that he 
 ever was or ever will be fair. It is the mind which 
 individualizes each subject. But since the indivisi- 
 ble is in the twofold state either of potentiality or
 
 160 ARISTOTLE ON THE [BK. III. 
 
 actuality, there is nothing to preclude the mind when 
 thinking upon extension, from thinking upon it as 
 indivisible, for it is indivisible, actually, and in time 
 which is indivisible ; as time, like extension, is both 
 divisible and indivisible. It may not then be said 
 that the mind thinks upon any subject in each half; 
 for extension exists only in potentiality, unless it have 
 been divided. But the mind, when thinking upon 
 each of the halves separately, divides the time simul- 
 taneously, and then time becomes such as the two 
 extensions ; and if the mind make a whole of the two 
 halves, it does the same with time in its relation to 
 them. The mind, however, thinks upon the indivisible 
 as species and not as quantity, in an indivisible portion 
 of time and by an indivisible part of Vital Principle ; 
 and this neither by accident, nor in so far as the sub- 
 jects thought upon, or the part by which, or the time 
 in which, it thinks, are divisible, but as they are indi- 
 visible. There is, in fact, in such cases a something 
 indivisible, although it may not be separate, which 
 makes time and extension to be one; and which holds 
 good for all continuity, whether of time or extension. 
 Now, the point and every analogous division, and 
 whatever is as the point indivisible, are made known 
 as being privation of something. The reasoning upon 
 other subjects is like this, for were it asked how the 
 mind is to recognise bad or black, it may be answered, 
 that it recognises them in some way by their contraries;
 
 CH. VI.] VITAL PRINCIPLE. 161 
 
 but that which recognises them must, in potentiality, 
 be the thing recognised, and be present also in it. If 
 to any one of the senses there is no contrary, then that 
 sense recognises itself, is in activity and separate from 
 all else. An affirmation, like a negation, is something 
 in relation to something, and is always either true or 
 false ; but not so with the mind, as it is true when it 
 judges of any thing after its essence, and may not be 
 true when it judges of something in its relation to 
 something else. Thus, the visual perception of any 
 particular object is true, but whether a something 
 white which is seen be or be not a man is not in- 
 variably true ; and this holds good for abstractions. 
 
 11
 
 PRELUDE TO CHAPTER VII. 
 
 COMMENTATORS are generally agreed in regarding this 
 chapter as a series of ill-connected repetitions of 
 former statements and doctrines ; but, although 
 repetitions, they will be found to illustrate or tend 
 to the completion of some preceding opinions. It 
 maintains, in fact, the same dogmata, adopts the 
 same illustrations, and assumes a faculty, the repre- 
 sentative of a sensorium, which physiology could not 
 then supply ; and thus, although the wording may 
 differ, the purport is the same. The term evepyfia 
 (which was before alluded to) is employed, in a more 
 especial manner in this chapter, and as neither its 
 meaning is obvious nor its equivalent easily selected, 
 it may be well to offer a few words in explanation of 
 it. Although it is opposed, like the e'i/xeA.e'^;eia, to 
 8i/i/a/ji<?, still the two terms are not synonymous ; for 
 the former (the evepyeia) seems to relate to action 
 in some form, and the latter to completion or deve- 
 lopment of something out of an imperfect or nascent
 
 PRELUDE TO CHAP. VII. 163 
 
 condition. Action must be implied, it is true, in 
 completion or development, and, therefore, the evep- 
 yeta may be contained in the evreXe-^eia, although this 
 may not hold good reciprocally. But the first para- 
 graph may be cited as an example of what apparently 
 needs elucidation "knowledge, is, it is said, w/ten 
 active, (latine, in actu,) (tj KOT' evepjeiav tTrumjpti), 
 identical with," &c. "la science en acte est iden- 
 tique," &c. " scientia autem, ea quae* est actu, est 
 idem quod res" and knowledge or science here, by 
 metonymy, may, probably, mean the faculty by which 
 knowledge is acquired or exercised ; but what means this 
 peculiar state which identifies the knowledge with the 
 reason? All function presupposes activity and inertia ; 
 but the last as much implies identification as the first, 
 so that the distinction between activity and complete- 
 ness, although present, probably, to Aristotle, is not 
 obvious to a modern student. The definition 1 of the 
 term, although dwelt upon at length, fails, it may be 
 from the difficulty inseparable from abstract specula- 
 tions, to shew either what is strictly implied by it, 
 or how it differs from the eWeAc'^eja; it is evident 
 that motion, in some modified sense, in the process 
 of completion, is to be understood ; but beyond this, 
 
 1 Metaphytica, vni. 6. I. 
 
 11-2
 
 164 PRELUDE TO CHAP. VII. [BK. III. 
 
 vague as it may be, explanation cannot be carried. 
 Potentiality is related to it as to the evTe\i%eia, but 
 the relation is too dependent upon verbal distinc- 
 tions, which cannot be transferred, to admit of being 
 made evident even to the student of the original ; 
 and thus it may be asked, what is meant by know- 
 ledge is, "when active" identical &c. or the same 
 words where they recur ? 
 
 CHAPTER VII. 
 
 KNOWLEDGE is, when active, identical with that which 
 is known; but knowledge, in potentiality, pre-exists in 
 the individual, and yet, strictly speaking, it does not 
 pre-exist, as all products are from a being in reality. 
 Now, it is the object of perception, which appears, by 
 its agency, to create sensation from the sensibility 
 which is in potentiality ; for it suffers neither impres- 
 sion nor change. So that this is a different kind of 
 motion ; for motion was said to be the act of something 
 incomplete ; but an act in an absolute sense is different, 
 as it is the act of something complete. Thus, a simple 
 sensation is like to a simple affirmation or a single 
 idea ; and as the impression may be grateful or pain- 
 ful, it is, as it were, affirmative or negative, and it bids
 
 CH. VII.] ARISTOTLE ON THE VITAL PRINCIPLE. 165 
 
 to flee from or pursue -after something; and percep- 
 tions of pain and pleasure emanate from the sentient 
 medium in its relation to good or evil, in so far as 
 things may be one or other. So actual flight from 
 something is identical with actual appetite, as the 
 fugitive impulse does not differ from the appetitive 
 stimulus, for they differ neither from one another nor 
 from the sentient medium ; and yet they do differ in 
 mode of being. Images belong, naturally, to the 
 thinking, as sensations do to the sentient principle ; 
 and as it may affirm or deny that anything is good 
 or bad, it bids to flee from or pursue after it. The 
 Vital Principle, therefore, never thinks without an 
 image; as the air has made the pupil what it is, the 
 pupil something else, and so with the hearing ; but 
 the last term is one, as the mean, to which belong 
 several modes of being, is one. 
 
 It has already been said by what faculty the mind 
 discerns that sweet differs from hot, but yet it may be 
 spoken of again here. It is then an unit of some kind ; 
 and an unit in the sense of a limit, for it is as an unit 
 and a limit in the relation, considered analogically and 
 numerically, which the unit bears to the limit. What 
 matters it, besides, whether our doubt is as to how 
 the faculty judges of things, generically, the same, or 
 opposite, as white and black ? 
 
 Let A = white be in relation to B = black, and let 
 C be to D as A is to B, and so reciprocally; if C, D be
 
 166 ARISTOTLE ON THE [BK. III. 
 
 properties of some one body they will be as the pro- 
 perties A, B, and the body will be one and the same 
 with the other, although not the same in the mode of 
 being; and the same reasoning will hold good, of 
 course, though A be = sweet and B = white. Thus, 
 the cogitative faculty dwells upon ideas in images, 
 and by images, independently of sensation, it in some 
 way determines what ought to be pursued after or fled 
 from ; but, when acted upon by images, it is moved 
 to think, and, perceiving the beacon to be on fire 
 and moving, it comprehends, by that common property 
 (motion), that an enemy is at hand. Sometimes, too, 
 by images or thoughts present in Vital Principle, that 
 faculty, as if seeing, calculates and orders things future 
 in their relation to things present ; and when it sug- 
 gests that something is grateful or hurtful, it bids to 
 pursue after or flee from it, as its biddings always tend 
 to action. And with respect to all which pertains to 
 inaction, the true and the false are in the same genus 
 with the good and bad; but with this difference, 
 that the former have an absolute, and the latter only 
 a relative signification. The mind dwells upon abs- 
 tractions, so termed, as it thinks upon a snub nose: 
 in so far as it is a nose of that character it cannot be 
 thought upon abstractedly, but in so far as it is con- 
 cave the mind can, by thinking intensely upon the 
 form, realise to itself the nose without the flesh in 
 which the form is embodied. Thus, too, the mind
 
 CH. VII.] VITAL PRINCIPLE. 167 
 
 thinks upon mathematical questions as abstractions, 
 although they are not really so, when they are thought 
 upon. 
 
 In fine, the mind when thinking, is, in act, the 
 thing thought upon. It shall hereafter be considered 
 whether or not it can be admitted that the mind, 
 without being itself apart from magnitude, can com- 
 prehend abstractions.
 
 PRELUDE TO CHAPTER VIII. 
 
 THIS chapter is a brief summary of the principal theories 
 and arguments which have been alluded to, and it 
 adds but little for comment. The opening para- 
 graphs are rendered less definite than might be 
 wished for, by the recurring particle irto<; and by 
 the substitution of ovra for irpdynara, although the 
 distinction between them is not very apparent. It 
 had just been said that "knowledge, in act, is 
 identical with what is known," and here the same 
 is predicated of Vital Principle, although with a 
 qualifying addition; and the meaning, in either 
 case, is dependent upon Aristotle's two sovereign 
 conditions. It may be understood how the intellect 
 as well as the sentient faculty can be regarded as 
 identical with their subjects, in the way that a 
 sentient organ, by reception of the form without 
 the matter, may be said to be identified with the 
 coloured or sonorous object; but it is not obvious 
 how this can apply to faculty or sense in poten-
 
 PRELUDE TO CHAP. VIII. 169 
 
 tiality, unless, indeed, as they are in abeyance, 
 without perception that is, so objects, not being 
 perceived, are without properties. 
 
 CHAPTER VIII. 
 
 HAVING thus summarily recounted whatever has been 
 said upon the Vital Principle, let us repeat that it is, 
 in some sense, all things which are; for things are the 
 subjects either of sentient perception or of thought, 
 and knowledge is, in some sense, things known, as 
 sensation is things sensually perceived. But let us 
 inquire how this is to be understood Knowledge, 
 then, like sensation is divided, when in potentiality, 
 into things in potentiality, when in reality, into things 
 in reality ; and the sentient and the cogitative faculties 
 of Vital Principle are, when in potentiality, identical 
 with thoughts and objects of perception, in potentiality. 
 But the question here must necessarily refer either to 
 things or the forms of things ; but the things them- 
 selves they cannot be, as it is not a stone but the 
 form of a stone which is in the Vital Principle. Thus, 
 the Vital Principle is, as it were, a hand, for as a hand 
 is the instrument of instruments, so the mind is the 
 form of forms, and sensation the form of things sensu- 
 ally perceived. Since there is, seemingly, nothing
 
 170 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 separate from perceptible magnitude, it must be ad- 
 mitted that all subjects of cogitation are in per- 
 ceptible forms, as well those termed abstractions as 
 those which relate to the conditions and changes of 
 the objects of perception. And, therefore, if a being 
 were without sentient perception, he could neither 
 learn nor understand ; as for reflexion the individual 
 must be able to call up an image of some sort, and 
 images are kinds of sensations, excepting that they 
 are immaterial. Imagination, on the other hand, is 
 something different from affirmation and negation, 
 for the true or the false is but a complication of 
 thoughts. But by what are primal thoughts to be 
 distinguished from such as are derived from images ? 
 Other thoughts, however, are not images, and yet 
 without images they could not be produced.
 
 PRELUDE TO CHAPTER IX. 
 
 THIS and the two following chapters are upon the parts 
 or powers rather, which give to animals locomotion ; 
 but, as the nervous even the muscular system had 
 not then been made out, the text is encumbered, 
 occasionally, as might be expected, with specula- 
 tions which may now seem idle, and distinctions 
 which are almost futile. Aristotle 1 makes " animals 
 to move and be moved for the sake of something, 
 which is the limit of all their movements; and the 
 moving powers of an animal are, perceptibly, he 
 adds, thought and imagination, election, will and 
 desire, which are all referrible to mind and appetite, 
 els vovv Ka\ 5petv. Thus, as imagination and per- 
 ception are alike able to direct an animal, they are 
 in one and the same relation to the mind. The 
 argument, in fact, dwells upon the motive as well as 
 the object for progression, without a word concerning 
 the agency by which it is to be effected, as if the 
 muscular power of the body were unknown, or 
 
 1 De Gen. Animalm. v. 16 ; n. 6. 46.
 
 172 PRELUDE TO CHAP. IX. [BK. III. 
 
 regarded only as the seat or source of the touch; 
 and yet the flesh was said to be tJie origin ' and very 
 body of an animal. The strength 2 of all animals is, 
 he adds, in the tendons (ij <<r^Js ci/ TO?? vevpoi^), and, 
 therefore, strength is greatest when they are full 
 grown; for the young have weak joints and deficient 
 sinews. 
 
 CHAPTER IX. 
 
 SINCE the Vital Principle of animals lias been 
 defined by the two faculties of judgment (which is 
 the office of thought with sentient perception), and of 
 locomotion, let us now, having dwelt sufficiently 
 upon sensation and mind, proceed to consider, with 
 respect to the motor power, what part of the Vital 
 Principle it may be. Let us consider, that is, whether 
 it is a part of Vital Principle and separate from it, 
 substantively or abstractedly, or whether it is Vital 
 Principle as a whole ; and if it be a part, whether it 
 is something peculiar and exclusive of those usually 
 attributed to Vital Principle, and which have been 
 alluded to, or whether it is to be considered as one 
 of them. 
 
 But a difficulty at once presents itself, both in 
 
 1 De Part. Animalm. ir. 8. i. a De Gen. Animalm. v. 7. 16.
 
 CH. IX.] ARISTOTLE ON THE VITAL PINCIPLE. 173 
 
 determining the sense in which we are to speak of 
 the parts of Vital Principle, and in settling how many 
 of them there may be. In one point of view, in fact, 
 the parts appear to be infinite in number and to com- 
 prise, not only those which some speak of as the 
 reasoning, passionate and appetitive, and others as the 
 rational and the irrational, but other parts also, which 
 by the distinctions employed in those classifications, 
 are brought into notice, and are more broadly distin- 
 guished from one another than are any of those to 
 which we have alluded. Those other parts are the 
 nutritive, which belongs to all plants and animals, 
 and the sentient, which cannot readily be placed 
 among either rational or irrational parts ; there is 
 the imaginative, besides, which differs in mode of 
 being from all the others, and yet it would be diffi- 
 cult to determine, amid the several parts of Vital 
 Principle, with which of them it is identical, or from 
 which it differs. Besides these, there is the appeti- 
 tive part, which, whether considered abstractedly or 
 functionally, would seem to differ from all others, 
 and yet it would be absurd to separate it from them ; 
 for volition is present in the rational, as decire and 
 passion are in the irrational part, and if the Vital 
 Principle be made up of these three, appetite must be 
 present in each of them. 
 
 But, to resume the more especial topic of this 
 chapter, what is that, let us ask, which confers upon
 
 174 ARISTOTLE ON THE [fiK. III. 
 
 an animal locomotive power ? Now, it may be sup- 
 posed that the generative and the nutritive functions, 
 which are innate in all living beings, originate the 
 motion concerned in the processes of growth and 
 decay, which equally belong to them all ; and with 
 respect to breathing and expiration, sleep and watch- 
 ing, which are subjects of much difficulty, we shall 
 enter upon the consideration of them hereafter. Let 
 us, however, consider what confers upon an animal 
 the power of progression. 
 
 Now, it clearly is not the nutritive faculty for 
 the movement of progression is ever for some end, 
 and is associated either with imagination or appetite ; 
 and then no being moves unless urged to it by desire 
 or fear, excepting, indeed, there be impulse from with- 
 out ; plants, besides, were nutrition the cause, should 
 be locomotive, and possess some organ to fit them for 
 that kind of movement. 
 
 Neither can it be the sentient faculty for there 
 are many creatures which are sentient, and yet sta- 
 tionary throughout their existence ; and if nature do 
 nothing in vain, and never, except in the case of 
 beings dwarfed or deformed, omits anything neces- 
 sary to existence, the creatures alluded to are perfect 
 creatures ; and as proof of this they are reproductive, 
 are capable of development and subject to decay, so 
 that they also ought to have organs to fit them for 
 progression.
 
 CH. IX.] VITAL PEINCIPLE. 175 
 
 Neither can the rational faculty or the so-called 
 mind be the motor power, for the speculative intel- 
 lect never thinks upon what is to be done, or suggests 
 aught concerning what should be fled from or pursued 
 after ; but this motion is the act of one fleeing from 
 or pursuing after something. Nor does that faculty, 
 even when reflecting upon any such object, at once 
 bid to flee from or to follow after it, as it often dwells 
 upon something terrible, or agreeable, without sug- 
 gesting alarm, although the heart may be set in 
 motion or some other part of the impression be agree- 
 able. Add to this, that although the mind may bid, 
 and the reason suggest that something should be fled 
 from or pursued after, the individual does not neces- 
 sarily move, but acts as does an intemperate person, 
 according to the dictates of passion. It is thus, occa- 
 sionally, we see that a physician, although versed in 
 medical science, does not cure, as if there were some- 
 thing other than the science which had the power of 
 acting according to the precepts of the science. 
 
 It may be affirmed that the appetite cannot be 
 the positive cause of this motion ; for the temperate, 
 even while desiring and yearning after something, do 
 not act in order to secure that for which they feel 
 appetite, but follow their understanding.
 
 PRELUDE TO CHAPTER X. 
 
 THE subject of locomotion is continued, and the motor 
 principles are said to be appetite and mind; but 
 mind in the sense rather of a perceptive or sentient 
 than a purely intellectual faculty; and yet it is 
 neither the centre of sensibility nor imagination, 
 although it partakes of the nature of each of them. 
 The imagination, which many are said to follow 
 against judgment, is evidently the voluntary species 
 of which man alone partakes; and the other, which 
 is allotted to the lower animals, may be regarded as 
 instinct. The mind, as a practical faculty, is to be 
 distinguished from the theoretical or speculative 
 intellect, which has for its object the discovery of 
 truth, as the other has the preservation of the body. 
 The argument is complicated, and made less appre- 
 hensible by the technicality and great precision 
 of its wording : thus, TO opf^rov, or object desired, 
 is food, and appetite is the stimulus or feeling 
 of hunger which compels to move; the practical
 
 PRELUDE TO CHAP. X. 177 
 
 mind (Sidvota irpaKTiKrj) is the sentient faculty, and 
 the beginning of the action, which is the satisfaction 
 of the appetite, completes or is the last of the 
 series. Thus, these two, the appetite and practical 
 thought (which is sentient perception) are motors, as 
 being both stimulus and desire, and the object 
 desired (food, that is), acting upon the sentient 
 perception, urges to locomotion for the attainment 
 of it; the imagination, as an instinctive power, is 
 said never to impel to move, save for the satisfaction 
 of necessary wants. 
 
 CHAPTER X. 
 
 THOSE two faculties, the appetite and the mind, appear 
 to be the motor principles in animals the mind, if 
 the imagination might be set down as being a kind 
 of thought ; for many against knowledge follow their 
 imaginings, and other animals are moved neither by 
 thought nor calculation, but by imagination. Thus, 
 those two faculties, mind and appetite, are locomotive 
 powers ; but, then, it is mind in the sense of a calcu- 
 lating and a practical faculty, and which differs from 
 the speculative mind by the object to which it tends. 
 
 12
 
 178 ARISTOTLE ON THE [BK. III. 
 
 Now, every appetite tends to some object, for the 
 appetite, which is the beginning of the practical mind, 
 has ever some object in view, and that object is the 
 beginning of the action. So that these two, appetite 
 and practical thought, may reasonably be regarded as 
 motor powers for the object longed for impels to 
 move, and then, through it, the practical intelligence 
 impels, because its origin is the object longed for ; 
 and when imagination may incite to move, it never 
 does set in motion without appetite. Thus, it is the 
 object longed for alone which produces motion ; for if 
 there were two motives, mind and appetite, they 
 would produce motion according to some common 
 formula. But as the case is, the mind does not 
 appear to produce motion without appetite, for voli- 
 tion is appetite ; and even when a creature may move 
 by calculation, it still moves by volition ; the appe- 
 tite, on the contrary, impels to move against calcula- 
 tion, for desire is a kind of appetite. 
 
 The mind then is always right; but appetite as 
 well as imagination may be right and may be wrong. 
 It is, therefore, the object desired which always ex- 
 cites to move, but then that object is a good or an 
 apparent good ; not however, a good in every sense, 
 but a practical good, and a practical good admits of 
 being otherwise than good. 
 
 It is manifest then, that it is that faculty of Vital 
 Principle, the so-called appetite which excites to
 
 CH. X.] VITAL PRINCIPLE. 179 
 
 move. But when Vital Principle is divided into 
 parts, and parts are distinguished by their faculties, 
 very many are made apparent, as the nutritive, the 
 sentient, the cogitative, the deliberative, and the ap- 
 petitive, and these differ from one another more than 
 do the desiring and the passionate. 
 
 The appetites admit of being opposed to one 
 another, and this occurs when reason may be opposed 
 to desire, but the opposition can be manifested only 
 in beings with a sense of time; for the mind com- 
 mands to resist on account of the future, while desire 
 urges to immediate compliance, as that which is good 
 appears, as the future is unseen, to be absolutely good 
 and absolutely grateful. Thus, the appetitive faculty, 
 in so far as appetitive, may, in a specific sense, be the 
 motor, but it is the object desired by appetite which 
 is the first to set in motion ; for without having been 
 itself moved, it incites to move from having been 
 thought upon or imagined; and there are several 
 such motors. There are three terms here : the motor; 
 then that by which it moves ; and thirdly, that which 
 is moved. But the motor is in the two-fold sense of 
 unmoved, and both motor, and moved the unmoved is 
 the practical good ; the motor and moved is the appe- 
 titive stimulus or appetition (for that which is moved 
 moves only in so far as it desires, and appetite is a 
 motion or an act of some kind) ; and the moved is 
 the animal. As the organism by which appetite 
 
 122
 
 180 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 effects motion is obviously corporeal, its nature must 
 be studied together with those functions which are 
 common to the body and the Vital Principle. But to 
 speak summarily, the organism whereby motion is 
 effected, is as a hinge in which coexist the beginning 
 and the end of motion for herein are the convex and 
 the concave, of which that is the beginning, and this 
 the end of motion; and therefore the one is at rest 
 while the other is in motion, as although, rationally 
 considered, the two pieces are distinct, yet, substan- 
 tively, they are inseperable. 
 
 In fine, then, as has been said, an animal is en- 
 dowed with self-motion to the extent of its appetition ; 
 but it cannot be susceptible of appetite without ima- 
 gination, and all imagination is either rational or 
 sentient, and of this latter kind other animals partake 
 also.
 
 PRELUDE TO CHAPTER XL 
 
 IT is by no means obvious what may have been meant by 
 " imperfect creatures," or in what sense desire, 
 unless it be as instinct, can be assigned to them; 
 for there is no trace throughout the zoology of 
 Aristotle, extensive as it is, of any such species of 
 being. One commentator has suggested polypi and 
 mollusca; but the former, in their present accepta- 
 tion, (improperly termed zoophytes), had not then 
 been observed, and the latter 1 could not, from the 
 description, have been regarded as " imperfect 
 animals." The "polypus" was the generic term for 
 the highest forms of the Cephalopoda, or " cuttle 
 fish." 
 
 1 De Part. Animalm, iv. 7. 4.
 
 CHAPTER XI. 
 
 LET us now consider the motor power in such im- 
 perfect creatures as have only the sense of Touch ; 
 and learn whether or not it is admissible that imagi- 
 nation and desire can be present with them. Now, 
 they do appear to be sensible of pain and pleasure, 
 and if so far sensible, they must of necessity have 
 desire. But how can imagination be present in 
 them ? It may, perhaps, be answered that, as their 
 movements are indeterminate, so those sensations are 
 present, but present in some indeterminate manner. 
 
 The sentient imagination belongs, as has been 
 said, to other animals, but that which is voluntary 
 is found only in such as are rational ; for it is matter 
 of calculation whether this or that shall be done, and 
 as the individual is to pursue what is larger and 
 better, he must be guided by a rule of some kind, 
 and thereby be enabled to individualize several diffe- 
 rent images. The reason why these creatures do not 
 seem to be capable of forming opinions is, that they 
 are without the faculty for drawing inferences, and 
 this includes opinion. But the appetite has no deli-
 
 CH. XI.] ARISTOTLE ON THE VITAL PRINCIPLE. 183 
 
 berative will, as appetite sometimes overcomes and 
 impels tlie will, and sometimes the will overcomes 
 and impels the appetite, as a ball is bandied to and 
 fro ; or appetite rules and impels appetite, when in- 
 temperance has the ascendancy. But that which is 
 superior is ever naturally more dominant, and pro- 
 ductive of motion in three different directions ; but 
 the intelligent faculty has no motion it remains 
 at rest. Although the conception of the universal 
 is to be distinguished from the conception of the 
 particular, (for while the former says that such an 
 one ought to perform such an act, the latter says 
 that such an one, and that / am he, ought now to 
 perform this particular act,) yet it is this latter 
 opinion rather than the former which impels to 
 move ; and although both may be motive, the one, at 
 least, is rather at rest, and the other is rather in 
 motion.
 
 PRELUDE TO CHAPTER XII. 
 
 As the treatise is drawing to a close, this chapter again 
 alludes to the distinction between the life in plants 
 and animals from the presence or absence of sensi- 
 bility thus, animals are distinguished from plants 
 by being sentient, as plants are from inanimate 
 bodies by nutrition and growth. Aristotle 1 placed 
 plants immediately after inanimate substances, and 
 says that they are distinguished, generically, by 
 degrees of vitality; that compared with other 
 bodies they appear to be almost alive (<r^e8ov iXa-nfp 
 ev\^v^ov) ; compared with animals, to be inanimate ; 
 and that the transition from the one to the other 
 is in an unbroken series. Thus, there are " marine 
 creatures," he says, "which cannot with certainty be 
 ranged among either animals or plants ; and sponge 
 has altogether the appearance of a plant." La- 
 marck 8 has substantively adopted this, as he, too, 
 
 1 Hist. Animedm, vni. i. 6. 
 3 Introduction, 77. 96.
 
 PRELUDE TO CHAP. XII. 185 
 
 commences with inanimate things (which, what- 
 ever their character, he distinguishes broadly from 
 whatever has life) and then passes to plants, which 
 he distinguishes from animal bodies, by being non- 
 irritable incapable, that is, of contracting any of 
 their solids, suddenly and repeatedly, while animal 
 bodies are, on the contrary, endowed with contrac- 
 tile power. Cuvier 1 observes, that "living and 
 organised beings have, from the earliest times, been 
 subdivided into animated beings beings, that is, 
 which are sentient and moveable, and beings which 
 are inanimate ; and as these are neither sentient nor 
 moveable, they are reduced to the common faculty 
 of vegetation or nutrition." It is not necessary, 
 then, as Aristotle remarks, that all living beings 
 should be sentient. 
 
 1 R&gne Animal, C. I. 18.
 
 CHAPTER XII. 
 
 IT is necessary to every living creature that it should 
 have a nutritive principle in order that it may live 
 and continue to live, from birth to death ; for it is 
 necessary to every thing generated that it should be 
 capable of growth, development and decay, and as these 
 cannot be carried on without nourishment, it is neces- 
 sary to all reproductive and perishing beings that 
 they should have a congenital nutritive function. But 
 it is not necessary to all living beings that they should 
 be sentient, nor can it be admitted that such as have 
 simple or homogeneous bodies can have Touch, or 
 that there can be an animal without Touch ; neither 
 can any beings be sentient but such as are receptive 
 of form without the matter. It is necessary to an 
 animal, however, that it should be sentient, if nature 
 do nothing in vain for all things in nature are for 
 some end, or else they are accidents of things for 
 some end ; so that if there were any animal body fitted 
 for progression without being sentient, it would perish, 
 and could not attain to the end which is nature's 
 design. How, in fact, is such a body to be nourished?
 
 CH. XII.] ARISTOTLE ON THE VITAL PRINCIPLE. 187 
 
 As to creatures which are fixed, they obtain their 
 nourishment on the spot where they have been pro- 
 duced. It is not possible then, that a body which is 
 not fixed to one spot and which has been generated, 
 should have living principle and judging faculties 
 without being sentient. Nor can a creature sponta- 
 neously generated be sentient ; Why, let us ask, 
 should it be so ? The sensibility is for the greater 
 good either of the Vital Principle or the body ; but 
 neither of these can, in the case supposed, be effected 
 by it, as the one will not through it think the better, 
 nor the other be better fitted for its offices. Thus, 
 there is no living body free to move which is not 
 sentient. But if a body be sentient, it must necessarily 
 be either homogeneous or compound Now, homoge- 
 neous it cannot be, as in that case it would be with- 
 out Touch, and Touch it must of necessity have. All 
 which is proved thus Since an animal is a living 
 body, and all bodies are tangible, and tangible im- 
 plies whatever is perceptible to Touch, it follows that 
 the body of an animal must be sensible to Touch, if 
 the animal is to preserve its existence. The other 
 senses, as the sight, smell, hearing, perceive through 
 other media; but if an animal when touching were 
 without sensation, it could have no guide for avoiding 
 some things or seizing others, and so circumstanced, 
 it would not be possible for it to preserve its existence. 
 The taste, therefore, is a kind of Touch, for taste is the
 
 188 ARISTOTLE ON THE [BK. III. 
 
 sense for food and food is a tangible body; but sound, 
 colour and odour neither nourish nor contribute to 
 growth or decay. Thus, taste must of necessity be a 
 kind of Touch from its being the sense which is per- 
 ceptive both of what is tangible and nutritive ; and, 
 as these two senses are necessary tD animals, it is 
 manifest that there can be no animal without Touch. 
 
 The other senses, being for the higher good of 
 animals, are allotted, not to all but, only to particular 
 genera, as they are necessary to none but such as 
 have the power of progression. If, indeed, such a 
 creature is to preserve its existence, it must not only 
 be sensible of objects when touching them, but be able 
 also to perceive them when at a distance; and this 
 can be effected if it be sensible through a medium, 
 which, having been impressed and set in motion by 
 the objects of perception reacts upon the percipient. 
 And it is thus that the locomotive impulse acts until 
 it cease in rest that which impels something else 
 communicates along with impulsion impelling power, 
 and the motion is in a midspace ; and as the first 
 motor impels without having been impelled, so the 
 last is impelled without impelling, and the inter- 
 mediate links, of which there are several, both impel 
 and are impelled. So is it too with respect to changes 
 wrought in bodies, excepting that they are effected 
 without change of locality as if any one were to 
 tinge a portion of wax, it would be in motion until
 
 CH. XII.] VITAL PRINCIPLE. 189 
 
 it should be saturated; nothing like this, however, 
 can happen to a stone, but it can to water, and that 
 to a distance. The air is mobile in the highest 
 degree, and, provided it be still and in one mass, it 
 both acts and is acted upon. It is better, therefore, 
 in the case of refraction, to assume that the air, in so 
 far as it is one mass, (and it is so over every smooth 
 surface,) is impressed by form and colour, rather than 
 that visual rays issuing from the eye are refracted. 
 Thus, the air, in the case of vision, gives motion 
 to the sense, as if the impress upon wax had been 
 transmitted to its extremity.
 
 PKELUDE TO CHAPTER XIII. 
 
 THERE were four admitted elements, fire and air, earth 
 and water, from which all things were supposed 
 to be formed; and the object here is to shew that 
 an animal cannot be homogeneous, connot be formed, 
 that is, of only one element. Now, earth was 
 supposed to give solidity, fire to be diffused through 
 all living bodies, and thus there remained only air 
 and water from which to constitute sentient organs ; 
 the earth was assigned, however, more particularly 
 to the Touch, but, as Touch is perceptive of other 
 qualities (as hot and cold) besides those of mere 
 Touch, it could not be constituted of that element 
 alone. The organs of relation, sight and hearing, 
 were formed, principally, of water and air, which 
 are the media for the transmission of visual and 
 sonorous impressions; and the smell partook more of 
 fire, as the Touch did of earth, yet not exclusively. 
 The theory is superseded by the increase of our 
 knowledge of external nature, but, in assuming
 
 PRELUDE TO CHAP. XIII. 191 
 
 elements, combination and proportion, it seems to 
 typify, as it were, an atomic theory. Hippocrates 1 , 
 also, taught that the human body cannot be exclu- 
 sively, either of air or fire, water or earth, or any 
 single element; although, he adds, "I do not quarrel 
 with such as think otherwise." Plato 2 , likewise, 
 " derived all things, so to say, from these four 
 elements, in due proportion and relation to one 
 another ; so that what fire is to air, that air is to 
 water, and water to earth, and each is, by affinity, 
 united with others, to form whatever is visible and 
 tangible." 
 
 1 De Natura Hominis. 
 
 2 Timceus, y., B.
 
 CHAPTER XIII. 
 
 IT is manifest that an animal body cannot be simple, 
 cannot, I mean, be only fire or air; for an animal 
 cannot have any other sense without having Touch, 
 and every living body is sensible to Touch, as has 
 been said. But all the elements, except earth, may 
 constitute sentient organs, as these all receive impres- 
 sions through something foreign to themselves and 
 through media ; but the Touch is made sensible by 
 touching bodies, and hence its name. And yet the 
 other sentient organs do perceive by Touch, but then 
 it is through something foreign to themselves ; while 
 Touch alone seems to perceive directly, through itself. 
 So that an animal body cannot be constituted of any 
 one of the other elements exclusively, nor can it be 
 formed only of earth; for the Touch is the medium, as 
 it were, for tangible impressions, and the organ is 
 perceptive not only of the distinctions which pertain 
 to earth, but of hot, cold, and all other tangible 
 qualities. Hence it is that we have no feeling in 
 bones, hair, or other analogous parts because they are 
 of earth; and plants for the same reason, being of
 
 CH. XIII.] ARISTOTLE ON THE VITAL PRINCIPLE. 193 
 
 earth have no feeling. It is impossible then that 
 there should be any other sense without that of 
 Touch ; and its organ is neither of earth nor any other 
 element exclusively. Thus, it is manifest that the 
 Touch is the only sense of which animals cannot be 
 deprived without dying ; that animals only can pos- 
 sess it ; and that it alone of the senses is necessary to 
 animal existence. On which account, other sentient 
 impressions in excess (as those of colour, sound and 
 odour) may injure the organs but do not destroy 
 the animal, excepting it be by chance, as when with 
 sound there is an impulse and a blow, or as when, by 
 visual or odorous impressions, other influences are set 
 in motion, which destroy the animal through the 
 Touch ; and when savour destroys life it does so by 
 communicating simultaneously a tangible impression. 
 But the excess of tangible impression, whether hot, 
 cold or hard, destroys the animal, because as every 
 impression in excess destroys the sentient organ, so 
 the tangible destroys that of Touch, and it is by the 
 Touch that animal life has been denned ; and it has 
 been shewn that an animal cannot possibly exist 
 without the Touch. Thus, the excess of tangible 
 impressions destroys not the organ only but the 
 animal, as that sense alone is necessary to its exist- 
 ence. Animals, in fact, possess, as has been said, the 
 other senses, not merely for existence but, for higher 
 enjoyment: they have sight, in order that, as they live 
 
 13
 
 194 ARISTOTLE ON THE VITAL PRINCIPLE. [BK. III. 
 
 in air and water, in a transparent medium in short, 
 they may see ; taste, that by discerning what is grate- 
 ful or nauseous in food they may have desire for and 
 move to obtain it ; hearing, that others may signify 
 something to them, and a tongue that they may 
 signify something to others.
 
 NOTES. 
 
 132
 
 NOTES. 
 
 BOOK THE FIKST. 
 
 CHAPTER I. 
 
 Note 1, p. 1 1. Truth in relation to nature, &c.] Aristotle 1 
 says that some beings exist by nature, and some by other 
 causes ; those by nature include animals and their parts, 
 plants and elementary bodies, as fire and air, earth and 
 water, for all such, evidently, exist, and exist by nature. 
 The objects, in fact, of nature's constitution are broadly 
 distinguished from whatever does not emanate from her 
 "for all her productions appear to have within them a 
 principle of motion, and of rest ; some for locomotion, 
 and some for the motions of growth, decay, and change. 
 But neither a bed, a garment, nor any other similar ob- 
 ject, whether formed of stone, earth, or composition, has 
 any such innate tendency to change ; and thus nature is 
 to be regarded as the source and first cause of motion and 
 rest in something which has, not casually but, innately, in 
 itself, from its origin, the capability of being so acted 
 upon." The term nature 2 , besides, is applied to any sub- 
 stance which, however rude and unchangeable, admits, by 
 its own properties, of being converted into something, as 
 1 Nat. AuscuU. n. i. 3 Metaphys. iv. 4. 3. 5.
 
 198 NOTES. [BK. i. 
 
 bronze is said to be the nature of a statue or of bronze 
 utensils, wood of wooden, articles, and so of other materials 
 and products. There were some who spoke of the essence 
 of natural bodies as nature, and as they made the primal 
 combination of particles, that is affinity, to be essence, 
 Empedocles maintained that "the nature spoken of by 
 men is only the combination of and change among par- 
 ticles." So that Aristotle confined the term nature to 
 existing beings and the processes by which they are sup- 
 ported and perpetuated, to living and organised matter 
 that is, while others widened its acceptation, and made it 
 applicable to the changes continually going on through 
 and by elementary substances. With him, in fact, it was 
 a living principle ; with others, a property or force, 
 whereby change is a law. 
 
 "The term nature," says Cuvier 1 , "in our own and most 
 other tongues, signifies, sometimes the properties which a 
 being derives from its birth (hereditarily) in contradis- 
 tinction to those which it may derive from adventitious 
 circumstances ; sometimes the whole of the beings which 
 compose the universe, and sometimes, again, the laws to 
 which those beings are subjected. It is in this last sense 
 that we are accustomed to personify nature, and out of 
 respect to employ its name for that of its author." 
 
 Note 2, p. 11. Its essence as well as its accidents] 
 Aristotle* observes that essence seems, most manifestly, 
 
 1 R^yne Animal, Introduction. 
 1 Metaphys. VI. 2. i.
 
 CH. I.] NOTES. 199 
 
 to be an innate property in bodies ; and, therefore, animals 
 and plants, and parts of animals and plants, as well as 
 natural bodies, as fire and water, air and earth, the ele- 
 ments, in fact, are essences ; to which may be added the 
 bodies which are derived from the elements, as the 
 heavens, stars, sun, and moon. Some, however, regarded 
 the boundaries of bodies, as surface, line, point, and unit, 
 as essences, rather than bodies or solids themselves. Thus, 
 essence, according to the first definition, seems to be 
 scarcely distinguishable from nature. Aristotle 1 , how- 
 ever, in another passage, considers it under four heads : as 
 mode of being, as universal, genus, and subject ; and sub- 
 ject he held to be essence in a fuller sense than the 
 others. Plato admitted of essence in forms, mathematical 
 abstractions, as also in sentient bodies ; and the Pythago- 
 reans first, and Plato later, adopted unity as essence. 
 Aristotle, in fact, seems to confine his definitions of these 
 abstract powers or entities to the outer world ; and others 
 to comprehend, under the term, the abstractions of pure 
 science, and the immediate operations of general laws. 
 
 The term " accident" was with Aristotle 2 , as it is with 
 us, significant of chance or possibility, as well as what is 
 necessary and constant. The former is exemplified by an 
 individual, when digging, finding a treasure, as this is an 
 occurrence neither necessary nor constant ; and thus there 
 can be no assignable cause, save chance, which itself is 
 undefinable, he adds, for an incident so purely casual. 
 1 Metaphys. VI. 3. i ; ix. 2. * Ibid. IV. 30.
 
 200 NOTES. [BK. i. 
 
 But it also implies properties which, although not essen- 
 tial, are, still, inherent, inalienable from, and distinctive 
 of particular bodies, as it is a property of the triangle to 
 contain two right angles ; these properties only are re- 
 garded as accidents in modern science, and such are 
 implied in the passage alluded to. 
 
 Note 3, p. 12. Concerning tlie thing itself, &c.] This 
 stands first in the enumeration of the categories 1 , which 
 comprize the ten following thing itself; (ri eV-ri) ; quan- 
 tity ; quality ; relation ; when ; where ; position ; reci- 
 piency ; action ; and impression. They are so designated, 
 Aristotle says, because there must ever be, in some one 
 of them, accident and genus, individual, and definition ; 
 for it is through them that premisses signify either indi- 
 vidual, or quantity, or quality, or other one of those 
 enumerated. It is made evident, thus when it is said 
 of a man lying down that it is a man or an animal, the 
 party both says what it is, and points' out its essence; 
 when it is something white which is lying down, then 
 the party designates its quality, as well. But these two 
 exemplifications seem to shew that the terms essence, ac- 
 cidents, category, like the abstractions of which they are 
 the representatives, cannot be clearly distinguished from 
 one another ; so that they may almost be regarded as 
 derivatives from one comprehensive idea. Essence is, in 
 the first of those instances, almost confounded with the 
 categories, although it is the object 8 of a special inquiry; 
 1 Topica, I. 9. i. * Catey. 5. i.
 
 CH. I.] NOTES. 201 
 
 and this seeming incongruity may have led some scholars 
 to set it down among them. 
 
 Note 4, p. 12. Some kind of demonstration or division, 
 &c.] Demonstration is, according to Aristotle 1 , a sci- 
 entific syllogism, and by scientific is meant, he says, the 
 method, through which we learn, with certainty, what a 
 subject may be ; and, 11 the knowledge be such, it follows 
 that demonstrative knowledge must be derived from con- 
 ditions which are original, immediate, and more appre- 
 hensible and causative, than the conclusion sought for. 
 Those conditions are, in fact, the suitable principles for 
 ascertaining that which is to be demonstrated ; as, without 
 them, the result will be, not demonstration but, a syllogism, 
 which cannot, with certainty, eliminate truth. Thus, 
 while demonstration* is a kind of syllogism, every syllo- 
 gism is not demonstration. Division is said by Aristotle 8 
 to be an imperfect syllogism, for it assumes what ought to 
 be demonstrated, and draws conclusions from a priori 
 reasonings. In this allusion to division, Aristotle may 
 be supposed to have had Plato in view, " as it was by 
 a process of dividing and subdividing that that emi- 
 nent man conducted his inquiries after truth ;" as, how- 
 ever, this method was considered by him to be a faulty or 
 imperfect syllogism, it may be that he alluded to it as 
 one which might be adopted, without altogether approving 
 of it as a mental process. 
 
 1 Analytic, b. I. i. 2. B Ibid. a. I. 4. i. 
 
 3 Ibid. a. i. 31.
 
 202 NOTES. [BK. i. 
 
 Note 5, p. 12. As those of number are not those of 
 plane surfaces, &c.] That is, the science of number dif- 
 fers, generically, from that of Geometry. The nature, so 
 to say, of numbers had been a subject of deep and curious 
 speculation long before and during the age of Aristotle, 
 and there lie scattered through his works notices of 
 writers and systems which, although in themselves inter- 
 esting to scholars, would, even were it possible to give a 
 clear summary of them, be foreign to the present inquiry. 
 Aristotle 1 , before entering upon number, denned "quan- 
 tity" as being, partly definite, and partly continuous 
 and the former. he constituted of parts which have no 
 mutual local relation to each other; the latter of parts 
 which have that relation. The "definite" quantity is 
 represented " by number and by a word ; the continuous 
 by line, surface, solid, and time and place, besides." In 
 order to shew that number is definite or discontinuous, he 
 observes, " there is no common boundary whereon the 
 parts of any number conjoin ; as if, for instance, five or 
 three be parts of ten, there is no common boundary 
 whereon five or seven can conjoin to make the whole 
 number, but each part is, for ever, a distinct number, 
 and thus number is among definite quantities." " Words 
 are, in like manner, among definite quantities ; and it is 
 manifest that words, uttered by the voice, are quantity, 
 in that they are measurable by long and short syllables, 
 and manifest too that there is no common boundary 
 1 Categ. 6. i.
 
 CH. I.] NOTES. 203 
 
 whereon the parts of a word, that is syllables, conjoin to 
 make the whole sound, and thus that each is for ever a 
 distinct sound. But a line, on the contrary, is continuous, 
 as there is no common boundary whereon its parts, that is 
 points, conjoin, as lines, to make a superficies, whereon 
 all parts of the solid conjoin ; so too time is con- 
 tinuous, for that which is present is conjoined with that 
 which is past, as it is with that which is future." Aris- 
 totle 1 , having shewn that there are these opposite con- 
 ditions of quantity, in a positive as in an abstract sense, 
 defines an unit (tj /xoVac) as being, in direct opposition to a 
 point, without position or place ; a line as being divisible 
 only in one way; a superficies as divisible in two, and a 
 solid, quantitatively considered, as divisible in three, and, 
 indeed, in all ways. Number is still regarded, of course, 
 as a collection of units ; the superficies as that which has 
 only length and breadth ; and the solid as that which has 
 length, breadth, and depth. 
 
 Note 6, p. 12. Among entities in potentiality or whether, 
 &c.] These terms run, like a golden thread, through all 
 the physiological works of Aristotle, and were adopted by 
 him in order to distinguish virtual from actual condition 
 or existence, the capability, that is, of becoming, by in- 
 nate force or power, an entelechy or reality, which is the 
 purport of the last term. They may be briefly exempli- 
 fied thus: an egg, e.g. is alive in potentiality it has 
 within it, that is, a principle, whereby, under genial 
 1 Metaphys. IV. 5. 24.
 
 204 NOTES. [BK. i. 
 
 circumstances, it can develope into a living being ; and 
 so a seed, while alive, is capable of becoming a perfect 
 living plant, as the egg or the caterpillar or the chrysalis 
 is, in potentiality, the future perfect insect or butterfly. 
 The terms comprehend, in fact, all the metamorphic con- 
 ditions of the animal and vegetable kingdoms, and have 
 a range of application wide enough to include life under 
 all degrees and forms. This was the first great idea in 
 their adoption, and although Aristotle made them to sig- 
 nify an analogous transition in moral or mental faculties, 
 (as when he speaks of a boy as a general, in potentiality,) 
 yet their real purport is to distinguish those two universal 
 conditions of living and sentient beings. Cicero 1 has al- 
 luded to these terms or rather to the entelechy, (as was 
 noted in the preface,) but, from not having contrasted it 
 with the potentiality, he seems to have mistaken its gene- 
 ral import ; and he may thus have been led to suppose 
 that Aristotle's intention, in this novel term, was to desig- 
 nate a special fifth nature, to be the source of motion and 
 the originating cause of mental faculties and natural 
 emotions. Montaigne*, also, in modern times, following 
 Cicero, speaks of the entelechy only, which he regards, 
 erroneously, as the motor power of the body "ce qui 
 naturellement fait mouvoir le corps." A hot dispute 
 prevailed among scholars, it may be added, before and 
 during the age of Rabelais 8 , (and which he has alluded to 
 
 1 Tusc. Disp. I. 10. a Essai, Lib. n. ch. xii. 
 
 3 La, Vie de Gargantua, Lib. v. ch. xix.
 
 CH. I.] NOTES. 205 
 
 with all his wonted wit and learning,) whether the term 
 should be eWeAe'^eia or eVSeAe'^eia ', he was, evidently 
 himself, one of the entelechists, as he says that the Lady 
 Quint-essence, who had had Aristotle, "that paragon of 
 all philosophy," for god-father, had been truly and cor- 
 rectly named Entelechy by him. 
 
 Note 7, p. 13. Wliether t/te difference is generic or 
 specific.] " The term Genus 1 implies a continuous series 
 of individuals having a like species or form, so that genus 
 may be predicated of man, so long as there may be a 
 continuous generation of human beings ; the term again 
 may be applied to the source whence individuals may 
 have descended, and thus some Greeks are of the Hellenic, 
 others of the Ionic genus, on account of their direct de- 
 scent from Hellenus or from Ion. And this applies so 
 much more to the progenitor than to external conditions, 
 that the descendants from a female constitute a genus. 
 Species 8 implies the mode of being of the individual, to- 
 gether with the primal essence ; and as the matter con- 
 stitutive of the genus is in the species, so species may be 
 regarded as parts of the genus. In modern classification, 
 genus signifies " a distinct but subordinate group, which 
 gives its name as a prefix to that of all the species of 
 which it is composed." The physical sciences have been 
 so widely developed, however, that, as those terms no 
 longer suffice for grouping the myriads of beings which 
 have been observed since Aristotle's time, naturalists 
 1 Metaphys. iv. 25. 28, * Ibid. vi. 75.
 
 206 NOTES. [BK. i. 
 
 have, in addition, adopted kingdom or class, order, sub- 
 genus, individual, and variety. 
 
 Note 8, p. 13. T/ie term animal, however, in an uni- 
 versal sense, &c.] This passage, which, in the original, is 
 even more elliptical than its version, has engaged much of 
 the attention of commentators without having been satis- 
 factorily elucidated some have explained it as a criticism 
 of the ideas or archetypes of Plato ; and others as an 
 objection to every universal term, which, although an 
 abstraction, is to typify actual beings; and this is, pro- 
 bably, the purport of the criticism. Thus 1 , "the origin 
 of the controversy, during the middle ages, between the 
 nominalists and realists, may be traced down to Aristotle 
 and his followers." Wording so elliptical must, of course, 
 be subject, according to the bias of opinions, to different 
 interpretations ; but if it imply objection to every abstract 
 term which is to embody, so to say, realities, this version 
 may be accepted as its interpretation. The Latin version*, 
 however, is, "Animal autem universale aut nihil est aut 
 posterius est, et quicquid itidem aliud communiter prasdi- 
 catur;" and the French 3 , "C'est que 1'animal pris en un 
 sens universel ou n'est rien, ou bien n'est que quelque 
 chose de tres ulterieur." 
 
 Note 9, p. 13. The mind before thought, <fcc.] Aris- 
 totle* says that among the philosophers who were engaged 
 
 1 Trendel. Comment. * Ed. Acad. Borriaica. 
 
 3 J. P. Saint Hilaire. 
 
 4 Metaphys. I. 3. 16 ; xin. 3. 5 ; xi. 7. 7.
 
 CH. I.] NOTES. 207 
 
 upon first causes, Anaxagoras and his predecessor Her- 
 moticus had maintained that, as in animals there is a 
 motor principle, so in nature there is mind, and that it is 
 the cause as well of the universe as of universal order ; 
 and thus " they assumed at once that mind is the cause of 
 the beautiful, the origin of being, and the source whence 
 motion is derived for every thing living." Anaxagoras, 
 in fact, regarded mind as the first cause of things (which 
 Ernpedocles was rather disposed to assign to the principle 
 of attraction, which he designated 0iAa, and held to be an 
 universal element), and maintained that, while all else is 
 but a combination of particles, it is homogeneous, impas- 
 sive, isolated, and pure. We are incapable, Aristotle 
 observes, in his comment upon these opinions, of continu- 
 ous thought and reflexion, because these are recreations too 
 lofty to be continuously maintained ; but, on this account, 
 watching (not being asleep, that is), feeling and thinking 
 are our most genial conditions, because from and through 
 them, we derive our hopes and recollections. Notwith- 
 standing, however, this acknowledgement, so to say, of 
 mind, as a sovereign principle, and its attributes, there is 
 no attempt to define its nature and its relations, or to 
 shew in what it was identified with or different from the 
 vital principle ; and this want of critical distinction be- 
 tween them is the more apparent as several epithets 
 (trpoyevea-TaTo^ 0eu)prjTino<: irpanTtKos 7ra0/TiKo?) are 
 introduced in the course of these physiological treatises, 
 which cannot but have modified the parent term.
 
 208 NOTES. [BK. i. 
 
 Note 10, p. 15. Whetfier all tJie emotions of Vital Prin- 
 ciple, &c.] These passages shew clearly the suggestive power 
 and perspicacity of Aristotle's intellect, and they point so 
 clearly to doctrines which had yet to be developed, that they 
 cannot be studied without feelings of surprise as well as 
 admiration. The brain 1 was, in that age, supposed to be 
 merely a supplementary organ to respiration ; and, from 
 its not giving out sensation when touched, and from im- 
 perfect anatomy, it was supposed to have no relation 
 whatever with the sentient organs or spinal cord. The 
 nerves, as cords of sensation, were unknown ; the very 
 term (yevpov), which has been transferred to them as nerve, 
 meant then tendon or sinew. Hence it is that, in modern 
 languages, a man is said to be nervous in the one sense, 
 and a delicate female to be nervous in the other. It was 
 thus, from intuition and study, that Aristotle drew this 
 train of suggestive reasoning upon the influences exercised 
 over our passions and emotions by the organs of the body ; 
 that he discerned, that is, the seat and source of the tem- 
 peraments. Bichat*, having a far wider range of anato- 
 mical knowledge, was able, by assigning to the brain and 
 ganglionic system their proper offices, to distinguish in- 
 tellectual faculties from passions and emotions, which 
 although human, still are temperamental and functional 
 to distinguish, that is, the animal from the organic life. 
 
 Note 11, p. 15. In tlie same, way all the emotions, &c.] 
 These passages are quite in accordance with all that phy- 
 1 De Part. Animcdm, n. 7. 4. 2 Recherches physiologiqnes.
 
 CH. i.] NOTES. 209 
 
 siology now teaches ; for although but repetition, it may 
 be said that Aristotle places the passions and emotions in 
 the organic life, and shews " that every individual must be 
 influenced by his particular temperament." Thus, as organs 
 predominate, or may be more or less active, individuals 
 are affected and modified, so to say, in temper as in cha- 
 racter. The temperaments ought to be subordinated, of 
 course, to the higher faculties ; but those organs are abiding 
 powers, and they are ever exercising an influence which 
 it is for reason to control or subdue. Plato, in the Timceus, 
 has discerned this great truth a 'mortal principle (ore TO 
 6injTov eVeo-rcAAe yevoi) is there assigned to the body, as 
 the seat of the passions and coarser appetites, while the 
 brain is represented as a soil fit for the divine seed of 
 wisdom ; and this will suffice to shew that this most gifted 
 man, although but imperfectly acquainted with physiology, 
 had perceived the co-existence in the human being of an 
 intellectual and, so to say, a functional existence. Des- 
 cartes 1 seems to have adopted opinions concerning the 
 " passions of the soul," which have much in common with 
 those of Aristotle ; but although so well acquainted with 
 his writings, he does not appear to have studied this 
 treatise. 
 
 Note 12, p. 16. But the physiologist and t/te metaphy- 
 sician would, &c.] The difference here dwelt ^ upon in 
 the mode of accounting for the same phenomena, accord- 
 ing to the bias given by studies or pursuits, will, it may 
 1 Les Passions de Fame. 
 
 14
 
 210 NOTES. [Ex. i. 
 
 be assumed, be of constant recurrence ; foi", as physical 
 science advances, it will become more and more difficult 
 for the same party to attain to a large and solid acquaint- 
 ance with the attributes of mind (abstractions, that is), 
 and the knowledge of " external nature." The self-same 
 differences, in fact, which were delineated so graphically 
 by Aristotle, are still to be traced in our almost exclusive 
 attention to the physical sciences, and our disinclination 
 to admit, in our inquiries, of any proof but such as can be 
 tested through and by the senses and observation. The 
 terms here rendered physiologist and metaphysician (terms 
 unknown, by the way, to Aristotle) in the Latin version 
 are naturalis, and disserendi artifex ; that of artisan is 
 faber ; builder, artifex ; and transcendental philosopher is 
 primus philosophus. 
 
 CHAPTER II. 
 
 Note 1, p. 19. Hence Democritus, &c.] None of the 
 works of this eminent man have come down to us ; but 
 notices of his opinions lie scattered through the writings 
 of Aristotle, and these may suffice for the elucidation of 
 this and other allusions to him. Following his master 
 Leucippus, Democritus 1 , abandoning metaphysical subtle- 
 ties, looked into the constitution of the external world for 
 1 Metaphys. I. 4. 9.
 
 CH. ii.] NOTES. 211 
 
 the knowledge of natural causes ; and he was thus led to 
 adopt the hypothesis of indivisible and moving corpuscles, 
 in order to account for the universal law of motion. 
 " Several other philosophers l had, before their time, con- 
 sidered matter as divisible into indefinitely small particles, 
 but as they were the first who taught that these particles 
 were originally destitute of all qualities except figure and 
 motion, they may well be regarded as the founders of the 
 atomic system of philosophy." Democritus 8 maintained 
 that nothing can ever be produced from nothing, and that 
 " indivisible atoms (elementary corpuscles, that is) consti- 
 tute the essence of bodies." He adopted, as elements, the 
 plenum and vacuum, making the former, in contradistinc- 
 tion to the latter, to be entity, and the two to be, as 
 matter, the causes of things ; he maintained too, that they 
 are equally distributed through all bodies. He agreed 
 with Anaxagoras in believing that throughout all nature 
 there is a principle of combination ; and with his master 
 Leucippus, in regarding form arrangement and position of 
 particles, as causes of elementary distinctions among bodies. 
 But in some of this reasoning he was mistaken, Aristotle 
 observes, from not distinguishing the condition of poten- 
 tiality from reality, since the same object may simultane- 
 ously, when in potentiality, be and not be, although this 
 cannot hold good of the same when in reality. Democritus 
 also thought that, owing to the difference of sensation 
 
 1 Enfield's Hist, of PhOos. Vol. I. 4 . 
 3 Mctaphys.Vl. 13. 9 ; m. 5. 5 ; I. 4. 9. 
 
 142
 
 212 NOTES. [Ex. i. 
 
 produced by the same object upon the same individual, 
 truth either has no existence, or else it can hardly ever be 
 attained to by mortal beings. To return, however, to the 
 doctrine of atoms, Leucippus and Democritus maintained 
 that, as bodies are distinguished by forms, and forms are 
 infinite, elementary bodies must be infinite also ; but then, 
 with the exception of fire, which was said to be spherical, 
 they forgot to specify what the forms are ; and they denned 
 elementary bodies by greatness and smallness as well as 
 form. Thus, form motion and size are, according to 
 them, the constituents of these formative atoms, and, 
 accordingly, the larger atoms which are said to go to the 
 formation of bodies, are distinguished from the smaller 
 ones or motes (held to be visible only in the sun-beams), 
 which, as being endowed with vital properties, are alluded 
 to, in a succeeding passage, as supporting, through respi- 
 ration, the life of the animal. In fine, this doctrine of 
 atoms varying in form and size, constantly moving, and, 
 through attraction and repulsion, combining with and 
 separating from one another, prevailed in all the schools 
 of antiquity; and there may perhaps be traced in it a 
 faint outline of the present matured theory of atomic 
 proportion. 
 
 Note 2, p. 19. Hence, too, they make breathing, 
 &c.] This description conveys, under a rude exterior, so 
 to say, a description of the process of breathing or respi- 
 ration, as well as the purposes which it has to fulfil in the 
 animal economy " the contraction of the chest (expiration)
 
 CH. ii.] NOTES. 213 
 
 expels particles rendered effete, and these are supplied by 
 others from without, during inspiration ; and this alter- 
 nation continues so long as life endures." It emanates 
 from an early stage of physiology, no doubt, but yet it 
 does clearly intimate that without such an alternation life 
 could not be maintained that a renewing power from 
 without, and an expulsion of something prejudicial from 
 within, are necessary to animal existence. Democritus 
 (of Abdera), Anaxagoras and Diogenes are cited by Aris- 
 totle 1 as believing respiration to be necessary for all crea- 
 tures (in opposition to himself, who limited the process to 
 air-breathing animals), and he has given their account of 
 the process in fishes and oysters (molluscs). " Anaxagoras 
 says that fishes, during respiration, discharge the water 
 through the branchise, and that then, as there may not be 
 a vacuum, they draw in air which is in the mouth ; and 
 Diogenes maintains that, when fishes discharge the water 
 through the branchise, they draw in, by means of the void 
 created in the mouth, the air which is ever present in 
 water and encircling the mouth." Democritus advanced 
 a step nearer to modern teaching, in accounting for fishes 
 dying when out of the water by their then taking in too 
 much air ; as, when in the water, they can take in only 
 a moderate quantity." But all this was objected to, abso- 
 lutely, by Aristotle, both because of his own more restricted 
 views of respiration, and of the apparent discrepance of 
 the theories with common sense, and thus was he led, in 
 1 De Eespirat. i. i.
 
 214 NOTES. [BK. i. 
 
 this instance, to oppose theories pregnant with suggestion, 
 and advantageous to the progress of science. 
 
 Jfoie 3, p. 20. To the same point do they aho come, <fcc.] 
 The writers here alluded to are said by Philoponus to be 
 Plato, Xenophanes and Alcmaeon. Aristotle 1 observes 
 that, as nature is the origin of motion and change, it is 
 necessary, in order to comprehend motion, to understand 
 what nature is. Motion seems to be the property only of 
 continuity, and the infinite is displayed, first of all, in 
 what is continuous ; and, therefore, in definitions of con- 
 tinuity, there is frequent reference to the infinite, as if all 
 continuity were infinitely divisibla Besides these reasons, 
 without place void and time, there cannot be motion. 
 But whatever is in motion, must have been moved by its 
 own or by some other power, and this motor may be the 
 second or third of a series, as the staff, for instance, which 
 moves the stone is moved itself by the hand, which is 
 moved by the man ; and although the last of these may 
 be spoken of as the motor, yet the term is applicable rather 
 to the man, as being the first link in the chain. Thus, 
 the man who communicates motion by bis will is, himself 
 at rest ; and, therefore, it by no means follows, Aristotle 
 contends, that the motor should itself be in motion. 
 
 Note 4, p. 21. Homer has icell represented, <kc.] The 
 
 term a\Xo<ppoveu>v, rendered " changing his mind," occurs 
 
 but once in the Iliad, and there it refers, not to Hector, 
 
 but to Euryalus vanquished in the funeral games; and 
 
 1 Nat. Auscutt. m. i. vm. 5.
 
 CH. ii.] NOTES. 215 
 
 signifies stupefaction of the faculties rather than what is 
 here attributed to it. Thus, either Democritus must 
 hare misquoted, or the Iliad, since Aristotle's time, have 
 suffered, as is commonly believed, more than one mutila- 
 tion. The purport of the passage, however, is sufficiently 
 obvious. 
 
 Note 5, p. 21. Thus Democritus does not employ tfa 
 term mind, &c.] He made mind, that is, to be a sentient 
 principle and identified with those filings and emotions, 
 which Aristotle held, as has been shewn, to be but 
 emanations from the corporeal organs and functions, 
 to be manifestations, that is, of the temperament. An 
 apology has been offered for this attribution of mind 
 to all creatures, in that such a principle may seem to be 
 represented by the consummate order which prevails 
 in their constitution j and thus that Anaxagoras mav 
 have meant that, while it may be present, objectively, 
 in all beings, it can be present, subjectively, (as mind, 
 that is) only, in a few. Plato 1 seems to imply something 
 like this when adopting one essence or faculty which is 
 eternal and unbegotten, and another which has no 
 abiding and is perishable the one capable, by intellect 
 with cogitation, of comprehending unchangeable natures : 
 and the latter capable, by opinion with sensual percep- 
 tions, of comprehending whatever is casual and ephemeral. 
 
 Note 6, p. 21. Have said that the Vital Principle 
 comprises alljirst causes, <fca] Aristotle* observes that, a<? 
 1 Timceus, 27. D. 8 Nat. Avscult. n. 3.
 
 216 NOTES. [Bx. i. 
 
 every investigation is for the purpose of knowing some- 
 thing, and as we cannot be said to know before we can 
 comprehend wherefore a thing is what it is, (comprehend, 
 that is, its first cause,) so it is evident that we must thus 
 study the laws of reproduction destruction and change, 
 throughout nature, in order to be enabled to refer, for 
 each subject of investigation, to the first causes of the 
 phsenomena. This argument seems to confine causation 
 to natural operations in particular, that is, living bodies ; 
 but cause had then, as it has now, a far wider significa- 
 tion besides essence, individual being, elements, and 
 other admitted first causes, that of which anything is 
 made, was said to be its cause, as bronze of a statue, 
 silver of a goblet, and, in a general sense the maker is 
 the cause of the production, and he who alters, of the 
 change, &c. Thus, there was great latitude in the 
 enumeration of first causes. Thales 1 , the founder of 
 this branch of philosophy, maintains that water is a 
 first cause, because the earth rose from water. Anaxi- 
 meues and Democritus contend that, as air was before 
 water, so it is rather to be regarded as the first cause of 
 everything. 
 
 Hippasus and Heraclitus set it down as being fire ; 
 and Empedocles, adding earth, adopted four elementary 
 causes ; for he maintained, that these elements are un- 
 changeable and unproduceable, although capable of com- 
 bining with and separating from one another. He first 
 1 Metaphysica, i. 3. 5. 8.
 
 CH. ii.] NOTES. 217 
 
 adopted the four elements, in fact, as the first causes of 
 all things, although, as he makes fire to be the antagonism 
 of the other three, which he held to be of one nature, he 
 can hardly be said to have regarded them as more than 
 two. This doctrine of elements prevailed, in fact, down 
 to the time of Descartes 1 , who admitted, however, only 
 of three, fire, air, and earth ; and he maintained that all 
 the forms of inanimate bodies may be accounted for by 
 the motion form size and arrangement of particles, 
 without the aid of any agent, such as heat or cold, 
 moisture or dryness. Thus all elementary particles are, 
 according to him, first causes. 
 
 Note 7, p. 21. By earth we perceive, &c.] The 
 doctrine of elements prevailed even to the constitution of 
 the sentient organs, for, as sensibility could have no part 
 in the theory of that age, philosophers had adopted the 
 dogma, that like recognises and perceives by like, that air, 
 that is, perceives by air, water by water, and so for the 
 other elements ; and thus the organ of vision was supposed 
 to be of water, that of hearing to be of air, and that of 
 smell to be of fire. As illustration of which, Aristotle 2 
 describes " odour as being a vaporous exhalation, and, 
 as such, necessarily derived from fire (heat) ; and the 
 special organ of smell is said, on this account, to be 
 located about the brain, for the matter of cold (the brain) 
 is, in potentiality, hot" and, therefore, able to perceive 
 
 1 Du nombre des Elements. 
 
 2 De Sensu et Sen. n. 1 1 . 20.
 
 218 NOTES. [BK. i. 
 
 what is derived from heat. The visual organ is said to 
 be of water, and to see objects, not as being water but, as 
 being diaplianous, as this quality belongs to air as well as 
 water, but then water is more protective and condensed 
 than air, and, therefore, the pupil and the eye are con- 
 stituted of water. These are rude theories, no doubt, 
 and sorry substitutes for the knowledge of the brain and 
 its system ; but philosophy cannot rest upon a confession 
 of ignorance, and this hypothesis, unsatisfactory as it 
 may now seem, was for ages the admitted theory of 
 sentient perception. But this theory of Empedocles, 
 however otherwise faulty, may well be supposed, without 
 violence to the text, to convey in the terms a-Topytj and 
 i/e?^o, a knowledge, or perception rather, of attraction 
 and repulsion; and an assumption of these principles 
 may be traced in most of the systems of that time con- 
 cerning elementary combinations. This must be main- 
 tained with some reserve, however, as some have given a 
 more literal version of the terms in amor and discordia, 
 or lis, which, as moral or sentient qualities, seem to be 
 without any relation to elementary combinations. The 
 latin version of the phrase is, Terrain nam terra, lympha 
 cognoscimus undam, setheraque sethere; sane ignis 
 dignoscitur igne ; sic et amore amor, ac tristi discordia 
 lite ; and the French is, " Par la terre nous voyons la 
 terre ; 1'eau par 1'eau ; par 1'air, 1'air divin ; par le feu, le 
 feu qui consume; par I 'amour, T amour; et la discorde 
 par la discorde funeste."
 
 CH. ii.] NOTES. 219 
 
 Note 8, p. 22. In the treatises " upon philosophy," &c.] 
 These books are said to have been expositions of the 
 teaching of Plato and the Pythagoreans upon ideas and 
 the nature of the sovereign good, or philosophy, and to 
 have been gathered by Aristotle from the oral teaching of 
 his great preceptor. It is generally believed that they have 
 not come down to us ; but a more modern commentator 
 seems to have been persuaded that they are still pre- 
 served in the Metaphysics, (that store-house, where lie 
 scattered the fragments of every system of philosophy 
 that ever had any authority, ) and yet there is no passage * 
 in that work, in which Aristotle alludes directly to the 
 topics here cited by him. If a digest of Plato's* doctrine 
 of the elements may be offered, he makes fire and earth 
 to have been the first of created elements, because what- 
 ever is produced must be visible and tangible and corpo- 
 real, and nothing can be visible without fire, or tangible 
 without solidity, whence the body of the universe was, in 
 the beginning, constituted out of fire and earth; but 
 since it is scarcely possible for two elements so to coalesce 
 as to form bodies without the intervention of other 
 combining elements, the Creator placed water and air 
 between fire and earth, and made them to be in the same 
 relation to the first elements which they are to each 
 other and thus fire is to air as ai/r is to water, and air 
 is to water as water is to earth. The Pythagoreans* were 
 
 1 Vide Trendelen. Comment. * Timasus. 31. B. ct seq, 
 
 3 Metaphysica, I. 5. 6
 
 220 NOTES. [Bx. i. 
 
 the first who devoted themselves to mathematics, and, by 
 exclusive attention to that study, they were led, at first, 
 to consider their principles as the principles of entities ; 
 but as numbers must be before mathematics, they were 
 brought to perceive many resemblances to beings and 
 conditions in numbers, rather than in fire or earth, water 
 or air. Thus, they assumed that a particular combination 
 of numbers is justice, that another is Vital Principle and 
 mind, another proportion or fitness ; and further, perceiving 
 the proportions and impressions of harmonic sounds to be 
 numbers, and other things appearing to bear a resem- 
 blance to numbers, and numbers to be the first of created 
 entities, they assumed that the elements of numbers must 
 be the elements of entities ; and that the heavens and 
 every kind of harmony must be numbers. But some? 
 while they held that numbers are elements, believed odd 
 and even to be the origin of numbers, and, therefore, 
 elements in a stricter sense ; and, as the unit is derived 
 from odd and even, they regarded it as the origin of all 
 numbers. Enough, however, has been said for rendering 
 apprehensible to the general reader, the import of the terms 
 and the tenour of the argument ; and it would be idle, even 
 were the doctrine fully known, to attempt any such dis- 
 quisition as would be required for a full elucidation of this 
 the most abstruse, perhaps, of all the topics of antiquity. 
 
 Note 9, p. 22. There are writers who have combined, 
 &c.] Simplicius 1 and Philoponus attribute this opinion to 
 1 Vide Trendel. Comment.
 
 CH. ii.] NOTES. 221 
 
 Xenocrates, whom they praise as the ablest expositor of 
 the doctrine of ideal numbers. He maintained that 
 Vital Principle has in it an abiding source of ideas 
 congenial with a mobile, ever-changing nature, such as 
 pertains to the external world, and that hence it is a 
 number which, while unable to free itself from the nature 
 of things, approximates to ideas ; and in order to prevent 
 faculties so ungenial from being severed, he derived from 
 Vital Principle the faculty and origin of motion, by 
 which, as by a link, they are to be retained together. 
 Thus, he thought to reconcile the apparent discrepance of 
 the co-existence of ideas and things in the same being. 
 Plato 1 has well criticised, in one of his writings, the 
 varying theories of philosophers upon the number, nature 
 and relations of elementary principles. 
 
 Note 10, p. 23. Anaxagoras seems, as we have, &c.j 
 The writing of Anaxagoras, the Clazomenian, here 
 alluded to, appeared, according to Aristotle 2 , after those 
 of Empedocles, although, in age he was his senior ; and 
 Anaxagoras maintained, he says, that first causes are 
 infinite in number. Thus, that almost all homogeneous 
 bodies, such as water or air, can be produced or destroyed 
 only by combination and separation ; and that, admitting 
 of no other origin or destruction than these, they must 
 endure for ever. From all which it might be inferred, 
 that he admitted of but one cause, and that in the form 
 of matter. He made mind, to which he attributed 
 1 Sophista. 8 Afetaphys. i. 3. 9. B. xm. 4. 5.
 
 222 NOTES. [Ex. i. 
 
 intelligence, to be a first cause, (as Empedocles made 
 affinity to be an element,) to be innate in and the source 
 of motion in animals, as well as the cause, in nature, of 
 the universe and its order. 
 
 Note 11, p. 24. Tholes, too, from what, &c.] In this 
 allusion to the influence of the magnet, Thales may have 
 been criticising the opinions which made motion de- 
 pendent upon life. He was the founder of the school 
 which derived all things from one or more material and 
 indestructible elements; he believed water to be the 
 sole element, (whence he demonstrated that the earth is 
 from water), and was probably led, Aristotle observes, to 
 this conception, from perceiving that the nutrition of all 
 creatures is fluid ; that heat is produced from water, and 
 that by heat animals live ; and, then, that all seminal 
 particles are naturally fluid. 
 
 Note 12, p. 24. Diogenes, togetJier with some oilier 
 writers, &c.] It is probable that this opinion was 
 suggested to Diogenes by the respiration, which he knew 
 to be essential to animal existence and dependent upon 
 the air ; although the process itself, and the changes 
 effected by it, were of course then unknown. Air, how- 
 ever, was believed to be necessary for the maintenance of 
 life, and so it might well be regarded as the originating 
 cause of all things ; and more especially by one who saw 
 so far, as was shewn in a former note, into its mode of 
 agency. It is shewn by Aristotle 1 that he had well 
 1 De Part. ni. 2. 6.
 
 CH. ii.] NOTES. 223 
 
 studied the vascular system ; and he seems to have 
 perceived that the brain is the seat of sensation. In fine, 
 philosophers, generally, in adopting four causes, have 
 been divided between fire, water, and, as with Diogenes, 
 air; which he held to be the origin of all secondary 
 operations. 
 
 Note 13, p. 25. Others, as Critias.] The opinion that 
 blood differs from the other fluids and has an independent 
 vitality, has prevailed, no doubt, in all ages ; but Aristotle 1 
 placed it, as well as its analogue, the ichor, which circu- 
 lates in molluscs, insects, <fec., among insentient and excre- 
 mentitious parts, such as bone, nails, cartilage, and other 
 like parts. It may be added, too, that the brain was so 
 considered. "To conceive," Hunter * observes, "that the 
 blood when circulating is endowed with life, is perhaps 
 carrying the imagination as far as it can go, but the 
 difficulty arises from its being fluid, as the mind is 
 not accustomed to the idea of a living fluid. But when 
 all the circumstances of this fluid are considered, the idea 
 that it has life within it, may not appear so difficult to 
 comprehend, for every part is formed, as we grow, out of 
 the blood, and if it has not life previous to this operation, 
 it must acquire it in the act of formation." One of the 
 great proofs of the blood's vitality is to be found in 
 coagulation, as the blood, when circulating, is not subject 
 to certain laws to which it is subject when removed from 
 the vessels. 
 
 1 De Part. AnimdTii. i. 4. 8. a Hunter's Works, T. in.
 
 224 NOTES. [BK. i. 
 
 Note 14, p. 26. So many ivriters as admit.] Heat is 
 the antagonism to cold, for it is fixed 1 , and with a down- 
 ward tendency, while heat is mobile, and has an inclina- 
 tion upwards ; heat, again, tends to dilate bodies, while 
 cold acts by contracting them. Thus, as heat 2 separates, 
 and cold consolidates, they came to be looked upon as the 
 elements or causes of destruction, (as he^b appears to be 
 self-motive and a cause of change?) and restoration. But 
 as heat (eo> to boil or be hot) is derived from, or is the 
 synonym of life or living, (aw contr. w, aei/ cqntr. 
 tyjv,) so some made life, from this supposed identity, to be 
 heat ; and others, from the resemblance between cold 
 (\l/vxpos or >^u^o<:) and the Vital Principle, (v/^^*?) as 
 breathing was supposed, by all the physiologists, to be a 
 process for cooling the blood, made it to be cold. It is 
 hardly possible to transfer to another, and that not a 
 cognate tongue, the full sense of a passage which depends 
 upon etymology ; but the general import of these two 
 opinions may, perhaps, be gathered from what is here 
 said. Thus, Cervantes 3 makes his knight fix upon the 
 name Rocinante, because Rocin is a horse, or nag of the 
 ordinary character; but, as his charger is to have wide- 
 spread renown, and to be distinguished from all other 
 nags, it ought to have a sonorous and suitable appellation, 
 and this is realised, in his own opinion, by the suffix 
 ante, and hence, Rocinante. 
 
 1 Metaphys. xin. 5. 2 De Gen. et Corr. ix. n. 
 
 3 T. I. Cap. i.
 
 CH. III.] NOTES. 225 
 
 CHAPTER III. 
 
 Note 1, p. 29. It is not easy, hoioever, <fec.] That is, 
 if the Vital Principle be a first cause and an element or 
 combination of the elements, it cannot be determined, if 
 subject to external impulse, what its movements will 
 be if it be of fire, it must move upwards, if of earth, 
 downwards, and so for intermediate movements. Plato 
 maintains, as was said, that, as there can be nothing 
 visible or tangible without Jire or solid without earth, 
 tJiese were the first of created elements ; and that, as 
 there can be no enduring combination out of two elements, 
 avr and water were next created and placed between the 
 first two. 
 
 Note 2, p. 30. Now, the body is moved by translation.'] 
 This passage has been the subject of much and serious 
 controversy, both as to its meaning and its genuineness ; 
 and yet, although an argumentum ad absurdum, it is a 
 fair conclusion from those premises. Thus, if the Vital 
 Principle be an entity distinct from the body which it 
 animates, and if the body be moved, by translation, from 
 it, the Vital Principle, having also that movement, may 
 set itself free, and if able to do this, it may re-enter and 
 
 15
 
 226 NOTES. [BK. i. 
 
 resuscitate the body which it had left. The assumption, 
 in fact, is an evident objection to the opinion that Vital 
 Principle moves itself as it moves the body ; and seems to 
 be necessary to the completion of the argument. 
 
 The passage, however, has been regarded as an inter- 
 polation introduced by some Christian writer, (adeo verba 
 Christianum seculum referunt,) in order to support the 
 doctrine of the resurrection : and Trendelenberg, while 
 unwilling to suppress the passage, seems to question its 
 authenticity. The subsequent paragraphs are in support 
 of Aristotle's opinion that the Vital Principle, if self- 
 motive, cannot be subject to motion by other impulse 
 than its own, (just as that which is good in itself, cannot 
 be so by or for the sake of something else,) and that, if 
 it were so subject, its motion would be due to sentient 
 impressions. 
 
 Note 3, p. 31. Some philosopJwrs maintain.] This 
 passage is a covert satire of the doctrine of Democritus 
 that motion is transmitted through all nature by atoms 
 in constant motion ; and these are said to have been 
 likened by Philippus, the reputed son, according to 
 Meineke, of Aristophanes, to globules of quicksilver, 
 which, when poured in, made a wooden figure to become 
 moveable. It is uncertain, by the way, when this metal 
 was first employed ; it is here alluded to as a well-known 
 substance, and is so spoken of by Theophrastus. ' Pliny 
 
 1 Hist. Nat. 33. 32.
 
 CH. III.] NOTES. 227 
 
 says that " it was brought from the silver mines of Spain, 
 in the form of cinnabar, and, when freed from its ore, 
 used in metallurgy;" further, "that it is always fluid, 
 and an universal poison." 
 
 Note 4, p. 31. It is in this same manner, &c.j If the 
 Vital Principle be to the body what Plato, in the Timceus, 
 made the great animating principle to be to the Universe, 
 a source of intelligence and ordered motion, there must be 
 an accordance between terrene and celestial bodies and 
 movements ; but as earthly bodies are moved by objects 
 of sense and perception, and as their movements are not, 
 like those of the heavenly, in a circle, their natures must 
 be different. It would be idle to attempt to make a 
 digest of the opinions entertained in the Timceus, the 
 most abstruse and laboured of all Plato's works, or to 
 trace the analogy between the constitution and motions 
 of the supernal orbs, and the constitutions and conditions 
 of earthly bodies. But four points seem to be evident 
 that the universe moves by motions communicated by 
 the anima; that the anima is from the elements; that 
 it has so been divided, as to have an innate sense of 
 harmonic numbers ; and that it has been made to move 
 in the same circles as the sky. This summary is adduced 
 by Aristotle to shew how scarcely possible it could be to 
 adjust this speculation to his own subject of inquiry, and 
 he may have been led to criticise it the rather, as the 
 great principle of the universe is synonymous with his 
 own treatise; each is, in fact, -^v^tj. But to quote the 
 
 152
 
 228 NOTES. [BK. i. 
 
 learned ' commentator, " Platonem in Timceo quam 
 maxime obscurum illustrare, hujus loci non est." 
 
 Note 5, p. 32. But, in the first place.] These critical 
 objections cannot be fully realised without reference to 
 the leading opinions and arguments of the Timceus, which, 
 although, perhaps, at the time, regarded only as specula- 
 tions and now stand self-confuted as physics, are enshrined 
 in words which shall endure, until mankind cease to 
 find delight and instruction in pure and abstract studies. 
 The first objection raised by Aristotle is to the ascription 
 of magnitude to that anima (which is to be necessarily 
 inferred from its being divisible,) as well as to the 
 intelligence or mind, which Ls identified with it ; for 
 magnitude would imply a material entity, and matter 
 conjoined with form and essence implies parts, and what- 
 ever has parts cannot either be self-existent, or indefinite 
 in duration. Another objection, much insisted upon, is 
 the movement in a circle, which cannot, it is said, be the 
 motion produced by the passions or appetites ; but the 
 chief topic is resumed, and the mind is shewn to be, 
 like the thoughts which emanate from it, immaterial. 
 Aristotle's subject, however, unlike that of the Timceus, 
 was confined to the agent or principle, whatever it be, 
 which imparts motion and other vital properties to organ- 
 ised matter. 
 
 Note 6, p. 33. Now, there are limits to practical 
 thoughts] The origin 2 of whatever is original is in the 
 1 Trendel. Comment. * Metaphys. V. i. 5.
 
 CH. III.] NOTES. 229 
 
 maker or creator, whether it be mind, or art, or a special 
 faculty it is an abstraction that is; but, whatever 
 is practical is dependent only on an agent, or his choice, 
 for the act is identical with what is chosen. Thus, prac- 
 tical thoughts are confined to the particular faculties and 
 organs which are required for securing what may have 
 been chosen. 
 
 Note 7, p. 33. Terminated by a syllogism.] The 
 syllogism 1 is an argument, in which, from given premises, 
 something different from the terms laid down results, 
 necessarily, from their admission. Modern definition is 
 much like this the syllogism is said to be an argument 
 of three propositions, having the property, that the con- 
 clusion necessarily follows from the two premises ; so that 
 if the premises be true, the conclusion must be true ; and 
 a conclusion is the proposition which is inferred from 
 certain former propositions, termed the premises of the 
 argument. 
 
 Note 8, p. 34. The same incongruity] This is an 
 objection by Aristotle to the doctrine of metempsychosis, 
 adopted by the Pythagoreans, and, being placed upon 
 obvious physical relations, it may be considered as irre- 
 fragable. Thus, philosophers held numbers to be elements, 
 and perceived in them and their combinations resem- 
 blances to, or types of faculties and sentient properties, as 
 has been observed. Their doctrine* was, " that man 
 consists of an elementary nature, and a rational or divine 
 1 Analytic, a. I. i. 6. * Hist, of Philos. Vol. i. 397.
 
 230 NOTES. [BK. i. 
 
 principle, and that of this last, the divine is seated in the 
 brain, the passions and appetites in the liver and heart ; 
 that the rational part is immortal, the sentient principle 
 perishable." They further taught, that the imperishable 
 part, freed from the chains of the body, assumes a new 
 form, passes to the centre of the earth for judgment, 
 and, if not deemed worthy of associating with perfect 
 spirits, is returned to earth to inhabit another body, of 
 higher or lower nature, according to its former deserts. 
 This doctrine has been so developed and exemplified in 
 the final teaching of Socrates, before his death, that that 
 dialogue 1 may be regarded as a faithful exposition of the 
 argument and its merits. Aristotle, overlooking eveiy 
 supernal cause or agency, objects to the doctrine, not on 
 its own grounds but, by reasonings, which are purely 
 deductive ; and the doctrine is, no doubt, when tested by 
 physical science, incongruous. 
 
 Note 9, p. 35. Such opinions are, in fact, &c.] This 
 passage is apparently abstruse and ambiguous, owing to the 
 terms being applicable to more than one art or implement ; 
 and yet, " * as it involves a kind of antithesis between 
 the art and the implements, the Vital Principle and the 
 body," the general sense can be made sufficiently obvious. 
 The purport of the phrase is well given in the Latin 
 version : Perinde igitur dicunt atqui si quispiam artem 
 fabrilem fistulas ingredi dicat ; etenim ars quidam instru- 
 mentis, anima vero corpore utatur oportet. The French 
 1 Ffuedo. * Trendel. Comment.
 
 CH. IV.] NOTES. 231 
 
 version is less definite : " C'est absolument comme si Ton 
 pretendoit que 1'architecture peut se meler de fabriquer 
 des instruments de musique." 
 
 CHAPTER IV. 
 
 Note 1, p. 38. It is equally absurd to think, &c.] 
 This is an unanswerable objection to Empedocles and bis 
 followers who made all bodies to be combinations, in 
 differing proportions, of the elements for whether the 
 Vital Principle be harmony or a combination of particles, 
 there must, as combinations are various, (since that which 
 forms bone is not that which forms flesh,) be several prin- 
 ciples in each member of the body; and if it be not pro- 
 portion, there must then be a second Vital Principle to 
 maintain that relation. The succeeding passages are, 
 necessarily, from the absence of precise knowledge con- 
 cerning atomic proportion and relation, obscure ; but they 
 point to opinions which, although not based on experi- 
 mental science, anticipate, when closely looked into, much 
 that is now admitted. 
 
 Note 2, p. 40. Now, to maintain that Vital Principle, 
 &c.] The argument reverts to the question whether the 
 Vital Principle can be subjected to motion casually pro- 
 duced be subject, that is, to motion through the body 
 which is moved by it, and thus partake of locomotion ; but
 
 232 NOTES. [BK. i. 
 
 the Vital Principle, being an essence, cannot be subject 
 to casual motion ; and then it has been) shewn that a 
 motor is not, necessarily, itself in motion. There seems, 
 however, to have been some difficulty in refusing all 
 motion to the Vital Principle, since the emotions and 
 passions which emanate from it seem to be motions, or 
 combined with motions, as passion excites and fear de- 
 presses the motions of the heart, and deep thought furrows 
 the brow ; but Aristotle, in order to reconcile these with 
 his own opinion, has recourse to an hypothesis which is 
 left for future inquiry. It is well said, however, that the 
 man rather than the Vital Principle is moved by passions 
 and emotions ; and thus motion may descend from it, as 
 the first motor, and at rest, to the several organs, (act, that 
 is, upon the temperament,) or ascend to it, by perception 
 of the external world, for memoiy. Philoponus, comment- 
 ing upon this passage, observes, as proof that recollection 
 originates in the Vital Principle and thence permeates to 
 the body, that, "when reminded of any fearful incident 
 we turn pale, and when recalling a voyage we become 
 qualmish." 
 
 Note 3, p. 40. The mind seems to be a peculiar innate 
 essence, &c.] Aristotle has nowhere denned this great 
 faculty, to which he attributed so high a destiny and such 
 lofty privileges "intellectus nihil patitur ; est atque 
 manet ;" but the opinion was not exclusively his, nor did 
 it originate with him, for Anaxagoras 1 , and before him, 
 1 Metapkys. I. 3. 10.
 
 CH. IV.] NOTES. 233 
 
 Hermoticus made the " mind to be the cause as well of 
 existence in animals as of the universe and universal order." 
 There is, evidently, here a want of distinction between 
 mind and Vital Priuciple ; and it may be that, in order 
 to avoid the obvious objection of two bodies in one, 
 Aristotle has always delineated this faculty as homoge- 
 neous and pure ; that is, as immaterial. 
 
 Note 4, p. 40. For if an aged person.] This allusion 
 to diminished perception, by changes, from the influence 
 of time, in the sentient organs, implies all that can now 
 be said ; for could the organ be restored to its pristine 
 form, and its energies be, so to say, revived, the aged 
 person would see or hear as he did when young. The 
 body is modified, in fact, by age, just as it is, to use 
 Aristotle's apposite reflexion, by maladies and rioting, 
 which anticipate the otherwise slower processes of time ; 
 " Senectus non eo existat, quod anima sed quod id patitur 
 in quo inest, i. e. corpus, sicut in ebrietate et morbis." 
 
 Note 5, p. 41. Thus, too, thought and reflexion lan- 
 guish] Quid sit, quod intus perire dicatur, commenta- 
 tores quaerunt ; sed nihil definiendum, nisi quod oculi 
 similitudini respondeat l ; but Philoponus, who is here 
 cited, clearly perceived that the passage pointed to the 
 destruction of a corporeal organ, and not to a mere change 
 of form. Whenever, in fact, there is destruction, however 
 brought about, of a corporeal organ, there is almost 
 universally mental disturbance and delirium. 
 1 Trendel. Comment.
 
 234 NOTES. [BK. i. 
 
 Note 6, p. 41. The most unreasonable by far of all tJie 
 opinions, &c.] These passages are so associated with the 
 peculiar doctrines of the Pythagoreans ', that they can 
 hardly, within the compass of a note, be made intelligible 
 to the general reader. These held the unit, it may be 
 said, to be the origin of number, and the point to be the 
 origin of the line ; and so they made unit and point to 
 belong to one common genus. But the unit was said to 
 be a point without position, and, therefore, an abstract 
 entity, which, being without parts or distinctions, cannot 
 be either motor or moved, and, therefore, cannot represent 
 the principle of all motion. Thus, the opinion is objected 
 to as making the Yital Principle a number, which deprives 
 it of locality or position, and then as attributing motion 
 to it which, as a number, it is not susceptible of. The 
 following passages, which treat of the division of plants 
 and insects, further prove, by analogy, that the Vital 
 Principle cannot be a number, as, unlike a number, each 
 part seems to have, after division, all the properties which 
 it had while yet conjoined with the whole. The argument 
 is then turned against the doctrine of Democritus, if the 
 corpuscles be regarded as points, there must still be in 
 each point, as quantity, a motor and a moved ; and the 
 theory depended for support upon quantity, rather than 
 relations of size. Unless, then, the Yital Principle be 
 both motor and moved, which it evidently cannot be, 
 there must be a motor power for those corpuscles. 
 1 Topica, I. 1 8, 8.
 
 CH. IV.] NOTES. 235 
 
 Note 7, p. 41. How, indeed, is it possible.] This pas- 
 sage is very elliptical and obscure, but its purport seems 
 to be an objection to the doctrine of Xenocrates, a follower 
 of Plato, who maintained that the Vital Principle might 
 be separate from the body. The argument runs thus : if 
 the Vital Principle be a number, and if each unit be a 
 point, how, as the point is not separable from the line, 
 can the Vital Principle be separate from the body? 
 Although the point may be, abstractedly, apart from the 
 line, yet as the line is not divisible into points, (since 
 points are but the termination of the line) it follows that 
 the Vital Principle, when regarded as a point, cannot be, 
 actually, separate from the body. The Latin paraphrase is, 
 " Insuper qui fieri potest ut separentur et absolvantur a 
 corporibus, ipsa puncta ? siquidem lineae non dividuntur in 
 puncta 1 ; " the French is, " Comment est-il possible que les 
 ames se separent et se delivrent des corps, puisque les 
 lignes ne se divisent pas en points 1 " 
 
 1 Acad. Reg. Sorussica.
 
 236 NOTES. [BK. i. 
 
 CHAPTER V. 
 
 Note 1, p. 47. Now, three modes of defining Vital 
 Principle, &c.] There is here a want of conformity with 
 other definitions of the Vital Principle, which points 
 either to neglect on the part of copyists, or to want of 
 early revision; for, in one place, Aristotle has distin- 
 guished the animate from the inanimate by " motion and 
 sensibility," while in another he has conjoined with them 
 immateriality ; and here, also, he has three terms, but 
 incorporeity, as if to approach nearer to the doctrines of 
 his great preceptor, is substitued for sensibility. 
 
 Note 2, p. 47. This opinion has been adopted, &c.] 
 The elements, and the parts assigned to them in the 
 constitution of bodies, by the schools of antiquity, have 
 been noticed in a former note ; but the notion that, as 
 like perceives like, the Vital Principle, being derived 
 from the elements, must perceive each like, cannot account 
 for the perception of compound bodies, unless, (which is 
 an absurdity) it contain, essentially, all compounds what- 
 ever. This is all very hypothetical, no doubt, but then 
 it assumes that there are elements, and that elements 
 combine, by affinity, in different proportions, to form 
 different bodies ; and, thus, the doctrine may be regarded 
 as a faint outline of the matured theory of modern times.
 
 CH. V.] NOTES. 237 
 
 This is further shewn in the formation of bone, as given 
 in the verse quoted from Empedocles, and which, besides 
 proportion, admits heat as an agent in combination. The 
 epithets employed by that eminent writer are not so pre- 
 cise as might be desired, and it cannot now be determined 
 what was meant by the words "liquid light," or fire, 
 (i^'o-Tt? a 17X17) (was it phosphorus, in some form T) ; but yet 
 proportion and combination, under high temperature, are 
 quite apparent the Latin version of the quotation is : 
 
 " Cceperat ante duas tellus justissima vasis 
 Aeris ac fontis partes : Vulcanus et ipse 
 Quatuor ex octo adjunxit, quis Candida magna 
 Vis fcecundaque naturae confecerat ossa." 
 
 Note 3, p. 49. It is absurd to maintain, &c.] We have 
 had handed down, by the earliest writers, differences of 
 opinion, Aristotle l says, upon " action and impression ; " 
 but most of them agree in making like unimpressionable 
 by like, (since the one is not more active or passive than 
 the other,) and the unlike and different alone to have 
 been so constituted as to act and re-act upon one another. 
 Democritus stood alone in maintaining that the selfsame 
 like can be, at once, active and passive ; for he would not 
 grant that things which are, essentially, different, can 
 mutually act and re-act upon one another. And even 
 though things should seem to be different, there is ever 
 something like, he maintains, by which the impression is 
 made. The difference between these opinions, however, 
 1 De Gen. et Corr. i. 7. r.
 
 238 NOTES. [BK. i. 
 
 when followed out, is, after all, formal rather than sub- 
 stantive ; for, in either case, the Vital Principle, whether 
 like or unlike, must be material, as the opinion still 
 implies some kind of impression, and impression implies 
 material properties. 
 
 Note 4, p. 49. But to shew how many doubts, <kc.] 
 The earlier philosophers differed widely, as has been said, 
 upon the elements, both as to their nature and number ; 
 but those writers are evidently wrong, Aristotle 1 observes, 
 who admit of only one element and one nature, as they 
 take no account of incorporeal entities. Empedocles 
 adopted the four elements as constitutive of tlie matter of 
 bodies, and hence the objection to his opinion, that " sen- 
 sation is produced by corporeal elements in the relation 
 of like ; " for those parts which are formed of earth (hair, 
 bones, <fec.) are insensible ; and, therefore, this element 
 cannot be perceptive of like. This assumption of insen- 
 sibility is, of course, too absolute, but such parts are no 
 doubt withdrawn, more or less, from the general sensi- 
 bility and sympathy of the living body. The term vevpa, 
 it may be observed, by the way, which here signifies 
 tendon or sinew, has now the meaning of nerves, the 
 conductors, that is, of sentient impressions ; and Galen, 
 who lived so many ages after Aristotle, and was well 
 acquainted with the brain, optic nerves, and office of the 
 nerves, still employed vevpov as a muscular chord. 
 
 1 Metaphyt. I. 8. i ; xin. 4, 5.
 
 CH. V.] NOTES. 239 
 
 Note 5, p. 50. It follows, too, from this theory, <tc.] 
 Empedocles regarded affinity (jtf>i\lav) as an element, but 
 what the deity to which he refused, so to say, repulsion 
 (TO velicos) is uncertain ; " whether Sphaerus ' or not, it 
 implies, at all events a being, to which ' repulsion ' (in 
 quern pugna non admittitur) had not been imparted." If 
 this, like affinity, were an element, then, as each sentient 
 being was supposed to be constituted of all the elements, 
 that deity must have been less favoured than other beings, 
 since he was unconscious of antagonistic properties, and 
 therefore, relatively, less intelligent than they. 
 
 Note 6, p. 50. But we are at a loss to know, &c.] 
 Aristotle here inquires what the particular faculty or 
 force may be which individualises, makes one, that is, of 
 objects ; and, thereby, gives to the sentient being the 
 consciousness of identity. It cannot be a sense, as the 
 senses are derived from the elements, and the elements 
 are akin to matter, while that, whatever it be, which 
 combines the faculties and powers of the body must, of 
 all, be the most influential ; and it may be inferred rather 
 than gathered from what is said, that it cannot be either 
 the Vital Principle or the mind. But do not all these 
 doubts and suggestions point to a central organ where 
 the sentient impressions, so to say, meet, and where con- 
 sciousness has its seat ? Does not the brain, which, as 
 the source of sensibility was then it may be said un- 
 known, fulfil all that is required by this suggestion 1 The 
 1 Trendel. Comment.
 
 240 NOTES. [BK. i. 
 
 brain is the organ which individualises different impres- 
 sions, and so enables the mind to compare and judge ; it 
 is the organ, too, which, retaining impressions, is the seat 
 of memory, and the source whence imagination draws its 
 images. The mind is again spoken of as higher in nature 
 than aught else, and thus Aristotle agrees with Anaxa- 
 goras who held that the " mind was the first of all 
 created entities and powers." 
 
 Note 7, p. 51. Thus, the reasoning in the so-called 
 Orphic verses, &c.] The epithet, " so-called," seems to imply 
 that there were doubts as to the author of these verses ; 
 be this as it may, they shew that animal life was known 
 to be especially dependent upon respiration. Aristotle's 
 criticism seems to imply that he was not acquainted with 
 respiration in any other form than that of air-breathing 
 animals, and therefore, not aware that the influence of 
 the air upon the system is necessary for the maintenance 
 of life in all creatures. Cicero * maintains that " Aristotle 
 denied the existence of the poet Orpheus ; " and that the 
 verses under that name were attributed, by the Pythago- 
 reans, to one Cecrops. 
 
 Note 8, p. 51. If it be well to form tlie Vital Prin- 
 ciple, <fec.] The wording as well as the meaning of 
 this objection to the opinion that " Vital Principle must 
 be formed from all the elements" is embarrassed and 
 obscure ; and, owing to the brevity of the argument, it 
 cannot be expounded with certainty ; but it seems to 
 1 De Nat. Dew. I. 38.
 
 CH. V.] NOTES. 241 
 
 imply that as one part of a contrary can judge itself and 
 the other, so all the elements cannot be necessary, since 
 nature never employs means in vain. ' " TJnum sufficit 
 ex contrariis, ut et hoc et alterum judicetur ; ad recti 
 nonnam etiam curvum exigitur; veruin sui index et falsi, 
 ut Spinoza loquitur." 
 
 Note 9, p. 52. There are writers who maintain, &c.] 
 Aristotle seems to have interpreted this opinion differently 
 from others, and, differently, it may be, (by regarding the 
 beings alluded to as the representatives of Yital Proper- 
 ties,) from its original import. Cicero 2 , for instance, attri- 
 butes to Thales, one of the wisest among the seven, the 
 opinion, that " it is expedient for men to suppose that 
 whatever can be perceived is full of gods, for, thereby, 
 all, as if placed in consecrated shrines, would become 
 purer." Whatever may be the value of that version, 
 the opinion could not be maintained when applied to 
 the cause of living actions, the origin, that is, of living 
 beings ; for, as bodies were supposed to be formed of 
 elements, and elements to be everywhere, the elements 
 themselves should be transformed into animals, which 
 involves an absurdity. 
 
 Note 10, p. 53. Since the faculties oj knowing, feeling, 
 &c.] Aristotle, quitting the question of life in its sim- 
 plest form, here reverts, after enumerating the properties 
 which characterise the highest forms of created beings, to 
 the question, whether or not all the properties may be 
 1 Trendel. Comment. * De Leyibut, II. 1 1. 
 
 16
 
 242 NOTES. [BK. i. 
 
 derived from one and the same principle ; and if not from 
 one and the same, what that is which combines the parts, 
 and makes them to be one. The passage which follows 
 is an evident allusion to the Timceus, according to which, 
 as has been said, reason is placed, as in a soil fit for 
 the heavenly seed, in the brain, the appetite and passions 
 in the heart, liver, or spleen ; and then comes the ques- 
 tion, what so connects those organs as to make them 
 mutually subsidiary to one another? not the body, cer- 
 tainly, it may be answered, as the body itself is but the 
 instrument of the Vital Principle. 
 
 Note 11, p. 55. But the living principle in plants, <kc.] 
 This passage is, to appearance, obscure, owing to its construc- 
 tion and scientific wording, but yet its meaning is obvious : 
 the living principle in plants, that which constitutes their 
 vitality, is assimilation, (growth, through nutrition, that 
 is,) and it exists in plants without sentient properties; 
 but sentient properties cannot, of course, exist without 
 nutrition, as nutrition is essential to life, and present, 
 therefore, in every thing which lives.
 
 BOOK THE SECOND. 
 
 CHAPTER I. 
 
 Note 1, p. 58. Now matter is potentiality, species 
 reality.] A few words may suffice for a further attempt 
 to elucidate these terms. Matter, then, per se, has no 
 definite existence, but with essence it becomes a some- 
 thing in potentiality, and then capable, under genial 
 conditions, of becoming a reality, the specific and indi- 
 vidual character of which depends upon form. Matter is 
 said to be comprised in essence, and therefore the distinc- 
 tion between them is hardly discernible, but Aristotle 1 , 
 under the term essence, comprises elements (earth, fire, 
 water and air) as well as derivatives from the elements, 
 and that because, while all other bodies are to be con- 
 sidered as dependent upon them, they pre-existed to, and 
 were the origin of all others. In another passage* he 
 assumes one universal, primordial, material essence, as 
 the source whence all things which are have proceeded ; 
 yet still he admits of a peculiar essence for each genus, as 
 the primal matter of pituita is whatever is sweet or oily, 
 1 Metaphys. ry. 8. i. a Ibid. VII. 42. 
 
 162
 
 244 NOTES. [BK. n. 
 
 and as whatever is bitter is the primal matter of bile. 
 Although essence may be an abstraction, yet a generic 
 character is clearly assigned to it in the text, and even in 
 recent times recourse has been had to such an assumption 
 in order to explain the difference between the secretions 
 of organs supplied with the same fluids and animated by 
 the same nerves. Thus, it was assumed that there must 
 be for each organ a peculiar essence, a substantia propria 
 (v\i%tj ova-ia), for the fulfilment of its functions as well as 
 the maintenance of its relations and sympathies with the 
 other parts of the system. The text seems to admit of 
 only one essence and one matter to be as the matrix for 
 all things, which is, of course, opposed to the doctrine of 
 elements and the formation of bodies by them ; but the 
 hypothesis could treat of them only as primordial 
 entities, however diversified by form their manifestations 
 may be. Aristotle was the first, however, who made form 
 to be the realising principle, to be that which confers 
 upon matter specific character, and constitutes the series 
 of being ; and this has been adopted by modern physio- 
 logists, as Reil makes form ' together with variety in t/te 
 combination of the elements " to be the cause of existing 
 differences in organic bodies and their faculties." 
 
 Note 2, p. 58. But bodies, and above all natural 
 
 bodies.] Living bodies, that is, are broadly distinguished 
 
 from all others by the innate power of reproducing 
 
 similar bodies, (similar in a specific sense, that is,) and 
 
 1 Miiller Handbuch der Phys. i. 27.
 
 CH. I.] NOTES. 245 
 
 which are the material for most of the works of man's 
 hand; as the human intellect can confer upon its 
 creations nothing save newness of form. Without assert- 
 ing that all which is has emanated from living bodies, 
 modern science has shewn that vast masses of matter, 
 now inorganic, were the product of what once had life. 
 
 Note 3, p. 59. Thus every natural body partaking of 
 life, <fec.] The text seems to be in accordance with what 
 had preceded, but it has been objected to by some on 
 account of its supposed obscurity ; it seems, however, to 
 imply that the three primordial conditions, matter, essence 
 and form, are necessary to, and concur in the formation of 
 every specific body. 
 
 Note 4, p. 59. And since the body is such a com- 
 bination, &c.] This passage is obscure both in word- 
 ing and purport, but it seems to imply that the living 
 body, being what it has been said to be, is indepen- 
 dent and self-existent, and, as such, cannot be Vital 
 Principle, because it cannot be among the subordinates 
 of a subject, which is the part seemingly ascribed to 
 Vital Principle, as merely realising what already had 
 existence in potentiality. 
 
 Note 5, p. 59. Now reality is, in the twofold significa- 
 tion, <kc.] These two terms, which, as has been said, per- 
 vade and illustrate Aristotle's philosophical writings, are, 
 themselves illustrated, as it were, here, \inder the forms of 
 sleep and watching the one, being the analogue of poten- 
 tiality, and the latter, of reality and thus knowledge,
 
 246 NOTES. [BK. n. 
 
 although possessed, yet, if not exercised, is only in 
 potentiality ; but when actually exercised, it is raised 
 up and converted into reality. It is not easy, without 
 periphrasis, to fix upon an apposite term for the cVf"/- 
 yopa-i^, which signifies, of course, a state the opposite to 
 sleep watching, adopted here, and the French reveil seem 
 to imply a forced condition ; and " being awake" is hardly 
 definite enough. 
 
 Note 6, p. 59. Only this is to be understood of a body 
 which may be organised, &c.] Organs are instruments 
 subservient to the purposes of the living body, as the 
 living body is subservient to the Vital Principle, and 
 Vital Principle, in its turn, subservient to nature's design 
 in creation. So that even plants, although insentient, 
 have organs, but organs which, in contradistinction to 
 those of animals, are homogeneous ; as the leaf is said to 
 be formative of all the parts of the fruit. Aristotle 1 
 distinguished the parts of animals, as is known, as homo- 
 geneous (da-vvde-ra), that is simple or of one nature, 
 as flesh, bone and sinew, and compound (a-vv6era) } as hand, 
 foot, &c., which are made up of different or unlike parts. 
 Thus, all the parts which are heterogeneous or unlike, are 
 made up of parts which are homogeneous or like, as a hand, 
 for example, is made up of Jlesh, tendons and bones ; 
 while the parts of plants, on the contrary, are but 
 developments of one simple part, that is the leaf. It is 
 manifest that Aristotle here points, suggestively, to the 
 1 Hist. Animalm, I. r. 3.
 
 CH. I.] NOTES. 247 
 
 development of organs by their own innate powers, and 
 thus he may be said to have originated a doctrine which 
 has been adopted, and, perhaps, realised as homologous 
 physiology, by modern science. Goethe 1 , before the 
 present century, had observed that " whoever looks even 
 casually at the growth of plants, cannot but perceive 
 that certain outward parts often change, and sometimes 
 assume wholly, at other times, partially, the form of parts 
 lying next to them. The secret affinity between the 
 different outward parts of plants, as leaves, calix, corolla, 
 stamen, which are naturally developed out of one another, 
 has been long known ; and this process, whereby one and 
 the same organ is seen to undergo manifold changes, 
 has been designated Metamorphosis of Plants" The 
 pericarp is, of course, the seed-vessel, the covering, that 
 is, of the seed, (as the pod of leguminosa, the hairy 
 covering of the chestnut, or the pulpy coat of fruit,) and 
 the germinal part of seeds is by Aristotle 2 compared to 
 the prolific end of the egg which is attached to the 
 oviduct, (rrj vff-rfpa,) as the seed is to pods, husks, or other 
 forms. The seed and fruit are well said to be analogous 
 to an animal body in its state of potentiality, (which may 
 be likened to a state of hybernation,) as ages may pass 
 away without extinguishing that latent existence which, 
 under favourable conditions, being resuscitated, can re- 
 sume the actions of life. 
 
 1 Goethe, Einleitung zur Metamvrph. der Pflangen. 
 8 De General, n. i.
 
 248 NOTES. [BK. n. 
 
 Note 7, p. 59. And the roots are analogous to tJie 
 mouth, &c.] This is one of those suggestive allusions 
 which characterise Aristotle's writings, and seem to have 
 anticipated knowledge that was yet to be realised ; for 
 had it been worked out, science might long since have 
 been in possession of the doctrine of homology. The 
 passage shews that Aristotle had perceived that parts 
 might be designated after their functions rather than 
 their forms, for it is the same process in plants, he 
 observes 1 , only they take in food by their roots, out of 
 the earth, already concocted, and hence they have no 
 excrementitious matter ; as for them, the soil and its 
 warmth are as a stomach, while animals have within 
 them a soil, that is a stomach, from which they draw 
 nutrition, as plants do from the earth, until digestion 
 have been completed." 
 
 Note 8, p. 60. It is, therefore, to no purpose.] An 
 exemplification of matter and form, as body and Vital 
 Principle, by the analogy of wax and the impress or form 
 given to it by the seal ; for these may typify a reality, as 
 a statue may typify a reality in the form given to the 
 marble. 
 
 Note 9, p. 60. It has thus then been explained] This 
 is a wider and closer exemplification than had been given, 
 both of the nature and influence of Vital Principle as 
 the essence in living bodies for it is to the living body, 
 
 according to this analogy, what the special property is to 
 t 
 
 1 De Part. Animalm. n. 3.
 
 CH. I.] NOTES. 249 
 
 the instrument. Thus, vision is the essence of an eye, as 
 cutting is that of an axe, for, could the organ or instru- 
 ment be deprived of those faculties, they would no longer, 
 save in name, be eye or axe ; and this holds good of the 
 living body, which, if deprived of its essence, its Vital 
 Principle that is, being no longer able to fulfil its 
 purposes in creation, is not to be regarded, save in name, 
 as an organised body. 
 
 Note 10, p 61. It is then obvious that neither Vital 
 Principle, <fec.] There is an apparent contradiction in this 
 passage, owing to the want of completeness in the argu- 
 ment the Vital Principle, as the essence, cannot be 
 distinct from the organs of the body, since they depend 
 upon it for their functions ; but the mind, being im- 
 passive, (dira6tj<: o i/oiJ<;,) and the cause of all the higher 
 faculties, may exist apart from all which is corporeal and 
 even sentient, and thus survive the body's death and 
 decay. Thus, Aristotle has elsewhere observed that it is 
 scarcely possible for anything to be of higher value or 
 more influential than the Vital Principle, and quite 
 impossible that anything should be more so than the 
 mind. 
 
 Note 11, p. 61. It is doubtful, however, whether, <fec.] 
 Whether, that is, the Vital Principle is separable from 
 the body, as the mariner is from his vessel whether, 
 as he is not necessarily involved in its- wreck, so it 
 may survive the death of the body. But the question 
 evidently pertains to psychology, and can scarcely be
 
 250 NOTES. [BK. n. 
 
 entertained amid inquiries into corporeal functions and 
 sympathies ; and the chief object of this treatise, is to 
 ascertain what that principle is which, for a stated time, 
 animates and presides over the functions of reproduction, 
 nutrition, growth and decay. It is evident, besides, that 
 Aristotle has annexed, so to say, this high privilege to the 
 mind, as the seat and source of all moral and intellectual 
 qualities and faculties. 
 
 CHAPTER II. 
 
 Note 1, p. 64. It is not only correct that the ivord- 
 ing, &c.] Aristotle 1 makes a definition to be a term 
 significant of what a thing essentially is, and, thus a defi- 
 nition may be employed in place of nouns, or one defini- 
 tion for another; but a noun cannot be accepted as an 
 adequate definition, since every definition ought to involve 
 some kind of cause. It is an expression 2 , in fact, which so 
 explains any term as to distinguish it from all else, as a 
 boundary line separates fields. Aristotle, again, makes it 
 to be something laid down (dea-is fnev eV-n) as the arithme- 
 tician lays down the unit as indivisible, quantitatively 
 considered; and yet this is no hypothesis, since the unit, 
 
 1 Topica, I. 5. i. Analyt. 6. 1.2. 7. 
 a Trendel. Comment.
 
 CH. II.] NOTES. 251 
 
 in itself, is not the same as the unit in relation that is 
 in combination. The conclusion is the close of a syllogism, 
 and to be distinguished from description which proceeds 
 from particulars, and from definition which is a summary 
 derived from universals. The distinction between these 
 terms is exemplified in the text by a geometrical figure 
 if we say that the " quadrature is that by which a rect- 
 angle with unequal sides is reduced to a square, this is a 
 definition but a definition bordering on description, as it 
 gives no account of how the operation is to be performed, 
 or whether it can be performed at all;" and if we say that 
 " the quadrature is the finding of a mean proportional, 
 the definition partakes of the character of an explanation 
 rather than a description ;" for if there be found " a mean 
 proportional between any two lines which make a rect- 
 angular figure, that proportional is the side of the required 
 square." 
 
 Note 2, p. 64. We say . . . that the animate, &c.] Nu- 
 trition, or the faculty by which matter can identify other 
 matter with itself and thereby develop and grow is the 
 rudimental principle of life, and the distinction between 
 living and inert matter; for inert unlike living matter, 
 increases in bulk, not through its own agency but, only 
 by the casual agglomeration of external particles. This 
 was assumed to be the sole faculty of plants, as Touch was 
 supposed to be the first and the only sense necessary to 
 animal existence ; but it may be questioned whether 
 nutrition and Touch are ever thus found as isolated and
 
 252 NOTES. [BK. n. 
 
 independent faculties. Cuvier * also looked upon nutrition 
 as the characteristic property of living matter; for life 
 consists, he observes, in the faculty possessed by certain 
 corporeal combinations of enduring for a time under some 
 determinate form, of drawing incessantly into their com- 
 position portions of surrounding substances, and of giving 
 back to the elements portions of their own substance." 
 
 Note 3, p. 66. With respect to some oftJwse faculties, 
 &c.] It is the purport of this passage to shew that, by 
 experiment and observation, we may obtain an insight 
 into the organs and functions of the body; but that, as 
 the mental faculties do not admit of being so scrutinized, 
 the investigation of them is, necessarily, obscure and com- 
 plicated. The distinction between sentient properties and 
 mental faculties is further exemplified by the lower forms 
 of animal existence, which continue to live, after having 
 been divided, in each of the parts; and as each part has 
 locomotion and manifests feeling, it is assumed that it 
 must also have imagination (instinct T) and desire. But 
 nothing at all resembling this can be predicated of the 
 mind, since, being indiscerptible, it is without parts, and, 
 so constituted, it cannot be subject to the change or disso- 
 lution of the body. 
 
 Note 4, p. 67. But something very like this has taken 
 place, &c.] Aristotle 2 is everywhere consistent with what 
 is advanced here for an animal is defined by him as a 
 
 1 Rdgne A nimal, T. i. 1 1 . 
 * De Part. n. 8. i.
 
 CH. II.] NOTES. 253 
 
 being furnished with senses, and, above all, with that 
 which first is manifested the Touch ; and, elsewhere ', he 
 says, that every animal, as such, must have some one sense, 
 since it is by sensibility that we distinguish what is from 
 what is not an animal. "It is further suggested that 
 animals may be distinguished, grouped that is, after 
 sentient and reasoning faculties, and that Zoology may 
 thus be founded on universal and demonstrable principles. 
 
 Note 5, p. 67. As that by which we live and feel.} As 
 life, that is, implies a body and living principle, so know- 
 ledge implies faculties and mind; and health the liability 
 to sickness ; but as Vital Principle is said to be the cause 
 of life and feeling, it is, as such, a creative energy, and 
 cannot, therefore, be matter and subject. It cannot, that 
 is, be a mere faculty or function, or be subject to what is 
 termed sickness. 
 
 Note 6, p. 68. On which account it is happily assumed, 
 &c.] This is a summary of what had been said concerning 
 that something, whatever it be, which constitutes a living 
 body and distinguishes it from inert or inanimate matter ; 
 and, although very indefinite, it still is all which can be 
 said concerning it. Aristotle guards against the assump- 
 tion, as Vital Principle requires for its manifestation 
 peculiar matter and exact relation, that it may animate 
 any kind of body, and thus the argument reverts to living 
 matter and its capability of organism, as the germ, so to 
 say, of animal existence. This necessary relation between 
 1 De Senxu ct Sens. I. 6. 7.
 
 254 NOTES. [BK. n. 
 
 the matter and principle is then advanced to refute the 
 doctrine of metempsychosis maintained by the followers 
 of Pythagoras ; as the active and passive, the agent and 
 subject, cannot possibly be mere casual associations. The 
 subject is further exemplified, in the closing paragraphs, 
 by those two conditions which pervade all Aristotle's 
 writings the body while yet in potentiality is, by the 
 Vital Principle, realised, converted, that is into reality ; 
 for Vital Principle can act only upon what is in poten- 
 tiality, and capable, under its influence, with form, of 
 becoming a specific creature. 
 
 CHAPTER III. 
 
 Note 1, p. 71. And all animals, without exception, 
 have the sense of Touch, &c.] Aristotle, having observed 
 that plants have only the function of nutrition, that is, 
 are not sentient, proceeds to the first and, therefore, most 
 universal of the senses that which may, as he assumed, 
 be present without any other, although there can be no 
 other without it. Thus, the Touch, as perceptive of food, 
 was supposed to be subservient to the appetite, and the 
 Taste, as discriminating, by tangible qualities, what in 
 food may be genial or otherwise, was held to be a modi- 
 fication of the Touch ; but the Touch alone was by 
 Aristotle regarded as distinctive of animal in contrast
 
 CH. III.] NOTES. 255 
 
 with vegetable existence. " According to the argument 1 , 
 he adds, by which appetite is said to be the mediate cause 
 of motion, there must, in living animal bodies, be some 
 such medium ; and the being, therefore, which by its 
 nature is incapable of motion, is impressionable by 
 appetite, through some other faculty." Plants, that is, 
 are not affected by the appetitive stimulus as are 
 animals. 
 
 Note 2, p. 72. As, however, we shall be more explicit, 
 <fcc.] The Touch being the earliest, so to say, of the 
 senses and distinctive of animal existence, is here held to 
 be the cause of appetite, as appetite is of motion ; and 
 as has been observed, the Touch was supposed to exist 
 independently of the other senses. This sense is said to 
 be especially discriminative of food, as animals are 
 nourished by substances which are hot and cold, dry 
 and moist, and these qualities are subject to it ; but it 
 can distinguish only by chance such other properties 
 (odour, colour, sound, for instance) as do not contribute to 
 nutrition. It is not easy to attach a definite notion to 
 the imagination here alluded to, but as Aristotle has 
 elsewhere distinguished the rational from the sentient 
 imagination, and as instinct only can be assigned to 
 creatures with one sense, it may be assumed that this is 
 its meaning. 
 
 Note 3, p. 72. It is clear, then, that there can be but 
 one, &c.] The triangle 8 forms all rectilineal figures, 
 1 De Matu An. 10. i. * Saint ffilaire.
 
 256 NOTES. [BK. n. 
 
 which have more than three sides, that is, " all such 
 figures may be divided into triangles, as the square into 
 two, the pentagon into three, the hexagon into four, &c. ; 
 and geometry has, since that age, reduced this to a special 
 theorem." 
 
 Note 4, p. 73. Thus, tJte inquiry must, <fec.] The 
 conclusion here arrived at enforces the necessity of 
 attention to individual existences, in order to ascertain 
 what may be the distinction, if such there be, between 
 Vital Principles ; so that the question reverts to former 
 speculations, whether or not there is but one Principle 
 variously imparted, or whether rather, each genus of being 
 has its own special cause of vitality and motion. It belongs, 
 also, perhaps, to the same speculation, to ascertain why 
 beings have been ranged in a series why, that is, such 
 manifold gradations of existence from man down to the 
 zoophyte ; unless, indeed, with other conditions of similar 
 character, it is beyond the pale of human inquiry. 
 
 Note 5, p. 73. But to such as possess some one only of 
 tJie faculties, &c.] It is far from easy to fix upon the exact 
 equivalents of the original terms (XoyMr/tov, 3a'i/oia, ^ai/ra- 
 <r('a,) which have been here rendered by calculation, judg- 
 ment and imagination; but the speculative intellect, (0e- 
 ptlTiKo*: vovs,') implies it may "be assumed" the human 
 mind or understanding, which was said to be impassive, 
 homogeneous, and distinct from all else. It might well, 
 therefore, be regarded as foreign to an inquiry, the 
 purport of which is to detect the animating principle
 
 CH. IV.] NOTES. 257 
 
 of bodies fitted for receiving its influences. It is some- 
 what strange that Aristotle, whose teaching was so 
 didactic, should nowhere have given a definition of that 
 principle or being, to which he has assigned so exalted a 
 destiny. 
 
 CHAPTER IV. 
 
 Note 1, p. 77. But since such beings cannot, <fec.] 
 The purport of this passage is almost too obvious for 
 comment, embodying the great fact of the perpetuation 
 of the species, and compensation, by reproduction, for the 
 death of the individuals ; and number refers, of course, to 
 individuals, species to the aggregate. 
 
 Note 2, p. 78. The term final cause, &c.] This is a 
 kind of parenthetical clause, intended merely to guard 
 against the supposition that the fact of some animals 
 having a fixed habitat, not being locomotive that is, was 
 unknown, or had escaped notice. 
 
 Note 3, p. 78. And this applies equally to growth and 
 decay.] Aristotle 1 perceived, although it may be in- 
 distinctly, that the source of nutrition is through the 
 blood he perceived, that is, that " the blood is replenished 
 by vessels, which arise on and are spread over the mesen- 
 tery, and which empty themselves into the cava and the 
 1 De Part. Animalm, IV. 3. 4. 
 
 17
 
 258 NOTES. [UK. n. 
 
 aorta;" the anatomy is, no doubt, imperfect, but it still 
 is an outline of the knowledge of the lacteals. It seems 
 to shew that veins gather fluid from the intestines, and 
 convey it to the large blood vessels ; but there was no 
 analogous knowledge, in that age, whereby the process of 
 decay that is absorption could be accounted for. The 
 term decay, therefore, was the mere expression for a 
 general fact. 
 
 The objection to the terms " upwards and downwards," 
 used by Empedocles to delineate the growth of plants, 
 suggests the advantage that would accrue to science, if its 
 terms were made sufficiently precise to fix, beyond doubt, 
 the several relations and positions of the same body, or 
 all bodies. And in the analogy between the heads of 
 animals and roots of trees, we cannot but perceive the 
 outline of a doctrine which has been developed, by modern 
 science, into homologous physiology. 
 
 Note 4, p. 79. The nature of fire seems to some 
 philosophers, &c.] This is an argument, drawn from the 
 agency of fire, to dispi-ove the then prevailing opinion, 
 that, as it alone of the elements appears to be nourished 
 and to grow, it may be the source of life and the origin 
 of living actions ; as they are shewn, by the contrast 
 between living and igneous properties, to be essentially 
 distinct from one another. The opinion may have 
 originated from the fact that heat accompanies digestion, 
 and as fire was by some held to be the first element, it 
 was readily supposed to be the agent in that process. As
 
 CH. IV.] NOTES. 259 
 
 an illustration of this opinion, it was maintained, even by 
 Aristotle l , that " food, taken into its appointed receptacles, 
 is vaporised and transmitted to the veins, in which, 
 undergoing change, it is converted into blood, and car- 
 ried onward to the heart." 
 
 Note 5, p. 81. T/tere are here three things, <fec.] The 
 meaning of this passage, apart from its scientific wording, 
 is sufficiently obvious that which nourishes is food when 
 digested; for food both acts and is acted upon by the 
 body, and, when so acted upon, it is assimilated to and 
 incorporated with its substance, through the blood. But 
 food, being dead, is contrary to the living matter, which 
 has, however, power to convert it into like, to assimilate 
 it, that is, to the living system. Thus, food, in its first 
 state, is contrary to or unlike, and in its last, or concocted 
 state, it is like the body ; and, therefore, the same element 
 is in one sense contrary, and in another sense like, acting 
 upon a contrary or like. So too the rudder, which directs 
 the vessel, represents the stomach, which converts the 
 food into nourishment for the body; and the sensibility, 
 which gives power to the stomach, represents the hand 
 which, through the rudder, directs the motion of the 
 vessel ; and the vessel is analogous to the body which 
 is nourished. 
 
 1 De Somno, 3. 3. 
 
 17-
 
 260 NOTES. [BK. ir. 
 
 CHAPTER V. 
 
 Note 1, p. 84. In our treatises upon action and im- 
 pression, &c.] Some commentators have, in the treatises 
 here alluded to, seen only a reference to other disquisitions, 
 as those upon " ' reproduction and destruction,' or decay," 
 7rfp\ yei/co-coK KU\ <j)0opd<: ; but as the passages which are 
 cited do not meet the whole question, it has been suggested 
 by Trendelenberg that the allusion may be to some other 
 work which has not come down to us. 
 
 Note 2, p. 84. It is difficult to understand, &c.] In 
 another chapter of this treatise, Aristotle has alluded to 
 the power possessed by the senses of recalling former 
 impressions ; of realizing images at will, that is, without 
 external objects. But the question here is to learn why 
 the senses, which were supposed to be derived from the 
 elements, from which or the accidents of which sensation 
 itself was derived, are not in constant activity. The 
 answer is, that the normal state, so to say, of the sensi- 
 bility is potentiality, and that it is insusceptible, there- 
 fore, of perception, without impression by something 
 from without to call it into action ; just as the combustible 
 material requires, in order to burn, the agency of fire. 
 But the comparison contains a converse proposition, as 
 while the material is required for the sensibility, it \sfire,
 
 CH. V.] NOTES. 261 
 
 which may be regarded as the sensibility, which is required 
 for the material. 
 
 Note 3, p. 84. Since we speak of sentient perception, 
 &c.] These passages upon perception aud sensation, which, 
 in themselves, when deeply inquired into, are sufficiently 
 obscure, are still less, if possible, apprehensible, on account 
 of the wording and the attempted illustration by the 
 leading terms, potentiality and reality. It is obvious, 
 however, that we may and do speak of an individual as 
 one who hears and sees, whether or not, at the moment, 
 conscious of sound or colour ; whether that is, awake or 
 asleep, active or quiescent, in potentiality or reality. 
 But an individual is, strictly speaking, only then seeing 
 and hearing when he is actually sensible of colours and 
 sounds ; just as an individual, to use Aristotle's analogy, 
 is only then to be accounted really learned, when actually 
 reflecting upon and exercising some one special subject of 
 knowledge. All attempts, however, to scrutinize the in- 
 timate operations, so to speak, of the sensibility under 
 impression from without or excitation from within soon 
 lose, even with the advanced knowledge of this age, the 
 character of inductive science, and are lost, as in the 
 text, in the maze of metaphysical abstractions. It seems 
 to be the object of the argument to prove, that the sensi- 
 bility, before being acted upon by external objects, such as 
 light, sound, colour, <fec., exists in potentiality and is unlike; 
 when acted upon, it is raised to the state of reality, and 
 thus made like to that by which the impression is made.
 
 262 NOTES. [BK. n. 
 
 Note 4, p. 85. Before proceeding further let us, &c.] 
 Tliis and the following passages are but repetitions of 
 what had been said, and further attempts at elucidation ; 
 they all too depend for a meaning upon the two great 
 leading terms. For motion is in a two-fold state when 
 generated by impulse from without it is passive, when 
 self-generated it is active ; and that may be regarded 
 as potential, this as real. Thus, if a body be at rest, 
 l>efore being impelled, the agent, by which it is im- 
 pelled, is unlike and active; but, when so moved, it is, 
 by the very act of motion, made active, and like to the 
 agent. 
 
 Note 5, p. 85. But we must draw a distinction, &c.] 
 These passages embody, in examples, the two terms so 
 often alluded to, and exhibit the opposite conditions of 
 human beings every man is learned, potentially, because 
 man is naturally so constituted as to be able to become 
 learned, or, being learned, is subject to an eclipse of his 
 learning by sleep, or disease, or inattention; and every 
 man, endowed with the faculties of his nature, may 
 acquire some one branch of learning, and, when there is 
 no impediment to his doing so, by the exercise of that 
 knowledge, become learned in reality. 
 
 The individual who is learned in the first sense cannot, 
 without a succession of changes, (while passing, that is, 
 from ignorance to knowledge), become, at will, learned, in 
 reality ; and he can, therefore, be accounted learned, only 
 in potentiality.
 
 CH. V.] NOTES. 263 
 
 Note 6, p. 86. The term impression, <fec.] The same 
 mode of illustration, through those two terms, is still 
 continued impression may be to an extent to destroy 
 sensibility, and obliterate, of course, sensation, or it may 
 be to that genial extent which raises, so to say, potentiality 
 to reality, and renders the being conscious of external 
 objects. So an individual, with knowledge yet potential, 
 that is, possessed but not exercised, can, by reflecting 
 upon it, without any change being wrought, render it 
 a reality ; for the possession of knowledge, like the endow- 
 ment of sensibility, implies the self-same two-fold condi- 
 tion. Thus, the state of reflection is to acquired 
 knowledge what external impressions are to sensibility ; 
 for, in either case, the agencies, when genial, occasion the 
 transition from potentiality to reality ; and so eliminate 
 practical knowledge or perfect consciousness. 
 
 Note 7, p. 87. Thefrrst change, however, of this kind, 
 &c.] It is not easy to perceive how this nascent condition 
 can be a change, unless the first germ of being may be 
 so regarded ; and, indeed, it may be supposed, from the 
 first moment, to have already, in potentiality, the powers 
 which are yet to be developed. It may be, too, that this 
 mysterious entity, along with the faculties and powers of 
 its own nature, may involve the idiosyncrasy of the 
 parent, for good or for ill ; which was indeed exemplified 
 in the life and death of the philosophical Montaigne 1 . 
 
 1 T. n. chap. 37.
 
 264 NOTES. [BK. n. 
 
 This capacity of the system for retaining dormant within 
 it a something to be developed, by iinknown causes, in 
 time, is exemplified in the atom of virus, which, after an 
 indefinite period, may, by mysterious agency, become a 
 reality in the form of Hydrophobia. Well might the 
 philosopher, when reflecting upon these incidents, exclaim, 
 " Qui m'eclaircera de ce progres, je le croirai d'autant 
 d'autres miracles qu'il voudra." 
 
 Note 8, p. 86. So tliat the process by which an indi- 
 vidual, &c.] This very obscure passage seems to intimate 
 that, as instruction is only the development of faculties 
 pre-existing and in potentiality, it is not to be regarded as 
 an impression; for such an opinion would imply, instead 
 of nature's ordinary process (development), a change 
 from a privative state (ignorance), as well as change in 
 habits of thought. This cannot, however, be insisted 
 xipon with much confidence ; the French version is, " Done, 
 ce qui fait passer 1'etre qui est en puissance a la realite 
 parfaite, & 1'entelechie, en fait d'intelligence et de pensee, 
 doit s'appeller, non du nom d'apprentissage, mais d'un 
 tout autre nom." 
 
 Note 9, p. 87. There is an analogy between, &c.] 
 Sensation, that is, is to the body what reflection is to the 
 mind, save that the one is produced by impression from 
 without, and, therefore, not subject to the will, while the 
 latter is the operation of will upon internal faculties. 
 Thus, sensation admits a series of individual impressions 
 which are to be analyzed and compared by the mental
 
 CH. VI.] NOTES. 265 
 
 operation ; and as the former becomes the parent of 
 inductive, the latter is the source of deductive science. 
 
 Note 10, p. 88. Let it for the present suffice, &a] An 
 obvious distinction of potentiality a boy is, potentially, 
 qualified to be a general ; that is, he has, by nature, 
 faculties and powers which, when developed, will fit him 
 for the office ; and so is one who, although of suitable age, 
 and whose faculties and powers are developed, may not 
 yet have acquired the necessary military knowledge. An 
 analogous distinction may be traced in sentient properties, 
 but it is too evanescent for precise description; and the 
 closing paragraph is a kind of summary of the conversion 
 of the potential and unlike into the real and like. 
 
 CHAPTER VL 
 
 Note 1, p. 90. The Touch indeed, &c.] This sense 
 has a wider range of perception than any other that is, 
 it is not restricted, like the Sight, Hearing, and Smell, to a 
 definite organism and one mode of impression ; and, besides 
 being extended over the body, it is essential to animal 
 existence. The text makes no allusion to the Taste, be- 
 cause this sense was regarded 1 as subsidiary to or a modi- 
 fication of the Touch. The special senses are Sight, Hearing, 
 and Smell ; Taste is less definite, as the tongue is sensible 
 1 De Semu et Sent. iv. i.
 
 266 NOTES. [BK. n. 
 
 of tangible as well as sapid qualities ; and Touch is ex- 
 tended over the body. Some properties, however, wliich 
 are enumerated, are subject to all the senses, and, hence, 
 termed common; but the attempted illustration of them 
 by "a kind of motion" (K/W/O-K TJS) does not, owing to its 
 vagueness, assist in explaining them. 
 
 Note 2, p. 91. An object is said to be perceived, <fec.] 
 An example in illustration of casual or accidental percep- 
 tion; but it is by its wording so obscure as to stand itself 
 in need of elucidation. The purport, however, seems to be, 
 that the percipient does not, by sight, (as sight distinguishes 
 only colour and form) discern what the white object really 
 is ; but the other senses, by some accidental perception, 
 coming in aid of the special sense, may determine that 
 the white object is a certain individual. There may 
 besides, perhaps, be a covert allusion to the two-fold 
 acceptation of the term accident, which signified then 
 as it does now both casual incidents and the real, or 
 inalienable properties of bodies ; and if so, the passage 
 may imply that the individual is perceived by chance; 
 detected, that is, by a mere guess. It is of little moment, 
 but the individual alluded to is said, by Philoponus, to 
 have been a friend of Aristotle's ; and that letters which 
 had passed between them were extant in his time.
 
 CH. VII.] NOTES. 267 
 
 CHAPTER VII. 
 
 Note 1, p. 93. TJie visible is colour, &c.] Aristotle 1 
 says that the faculty of Sight announces to us, dis- 
 tinguishes, that is, the manifold and various shades of 
 colours, on account of all bodies partaking of colour, and 
 thus by Sight, especially, we are able to perceive common 
 properties, such as form, magnitude, motion and number ; 
 but the Hearing, on the contrary, is perceptive only 
 of distinctions of sounds from sonorous bodies and the 
 variations of voice from such as have speech 2 . The sense 
 of " Hearing, however, contributes more than any other, 
 since speech is the channel for instruction, to the cultiva- 
 tion of the understanding." 
 
 Note 2, p. 93. All colour is motive of the diaphanous, 
 &c.] These passages seem almost to indicate a presenti- 
 ment of the modern or undulatory theory of light, for 
 they assume the existence of a diaphanous, that is, a 
 subtle medium which, by its motion, is creative of vision. 
 So too, the modern theory assumes a subtle elastic ethei*, 
 which has inertia without gravity, which fills space, per- 
 meates all bodies, and admits of being set in motion by 
 the agitation of the particles of ponderable matter, and 
 which particles, when set in motion, communicating a like 
 1 De Sensu et Sen*. \. 10. 2 I. n.
 
 268 NOTES." [BK. u. 
 
 motion to the molecules adjacent, act upon others, and 
 thus motion is propagated further and further in all 
 directions. The theory of Aristotle is much the same 
 there is a diaphanous medium which may well represent 
 the subtle ether, and which, when potential, that is 
 quiescent, is darkness, and when set in motion by colour, 
 (the property of which is to render it motive), is light, 
 renders objects visible, that is. Thus, the same diaphaneity 
 when passive, that is, potential, is darkness, when active, 
 that is, in reality, is light, and the cause of objects being 
 visible. The value of the hypothesis is diminished by 
 the identification of the " diaphaneity" with air and water 
 and solid bodies, because of their affinity with the 
 supernal region or firmament above, which, together with 
 all the heavenly bodies, was supposed to be of igneous 1 
 nature ; and to be corporeal, circular, and in constant 
 motion. 
 
 Note 3, p. 94. LigJit is the active state, &c.] The 
 diaphaneity which, when passive, is darkness, when set in 
 motion and made active, is light, is made visible, that is ; 
 and thus light, being a mere condition of the diaphaneity, 
 "is not a body, for, were it so, there would be two bodies 
 in one, which is an impossibility." It may now seem 
 strange that Aristotle should have paid so little attention 
 to the opinion of Empedocles*, " that light arrives midway 
 from the sun, before it reaches the sight, or the earth ;" 
 for although it differed from his own, in regarding the sun 
 1 Meteoroloffica, 3. i. 2 De Ccdo, ?. 3.
 
 CH. VII.] NOTES. 269 
 
 as the source of light and the distinction of day from 
 night, yet, in transmitted light, it supplied a motor, 
 which was required for the completion of his own theory 
 of sensation through the agency of a medium acted upon 
 by impulsion. 
 
 Note 4, p. 95. Now that which is without colour, &c.] 
 The diaphaneity, that is, when passive, is receptive of 
 colour and made active, just as the air, when quite still, 
 is more readily set in motion and made sonorous by per- 
 cussion ; and this leads, amid some confusion of thought, 
 to the consideration of those luminous appearances (ignes 
 fatui) which are visible only in the dark, by their colour. 
 'The precise nature of these appearances is still only 
 conjectural, notwithstanding the advance of chymistry ; 
 but they are supposed to be due to phosphyretted 
 hydrogen eliminated, under favouring circumstances, from 
 decaying animal and vegetable matter, and ignited by 
 contact with the atmosphere." 
 
 Note 5, p. 95. Therefore, witliout light colour is not 
 visible.] Colour, that is, by imparting motion to the 
 diaphaneity, renders it, from being potential and dark, 
 actual and visible, that is, light ; and thus, as without 
 light there is no colour, so without colour there is no 
 light ; and this lends support to the opinion, that the air, 
 as being a diaphanous medium, is essential to sight. 
 Aristotle had indeed maintained, in opposition to 
 Empedocles 1 and others, that vision is not caused by the 
 1 De Sensu et Sens. II. 15, 16.
 
 NOTES. [BK. n. 
 
 emanation of luminous rays from the eye as light proceeds 
 from a torch or lamp ; and he ridiculed the notion that 
 vision is precluded in the dark owing to the extinction of 
 those rays therein. It is probable that this theory first 
 led him to adopt a medium and its successive motion, as 
 the immediate cause of vision ; as he had accounted for 
 hearing by the propagation of the impulse given to the 
 air by the sonorous body. Aristotle was unacquainted 
 with the structure of the eye ; but he was aware, of 
 course, that it contains humours, and these he held to be 
 necessary, not as being aqueous that is elementary but, 
 as being diaphanous, for this property seemed to be as 
 requisite for vision within the eye, as it is for the trans- 
 mission of light to the eye. It was this assumed succes- 
 sion of action, after impression upon a diaphanous medium, 
 which led to the conclusion that the eye itself must be 
 diaphanous, and, therefore, that the visual power must be 
 somewhere on the inside of the eye ; and this is the only 
 approximation to a right knowledge of the retina and its 
 relations. 
 
 Note 6, p. 96. It has thus then been said, <fcc.] The 
 cause of colour being visible is sufficiently obvious from 
 what has been said ; but fire was said to be visible both 
 in darkness and in light, owing to its being, as fire, of 
 the nature of the firmament above, which was believed 
 to be fire, or something identical with fire. It may be 
 presumed that the subject was here introduced, in order 
 to notice and account for those luminous appearances,
 
 CH. VII.] NOTES. 271 
 
 which have been alluded to, and which, in that age, could 
 not but have been topics of wonder and speculation ; 
 they were irreconcilable besides, with the prevailing 
 notions of colour and light. 
 
 Note 7, p. 96. The air is the medium for sounds, &c.] 
 The air was by Aristotle held to be essential to sound ; 
 but it is not apparent why odour was supposed to be 
 transmitted by some modified condition of air or water, 
 unless, indeed, it was required in order to account for the 
 perception of odours by fishes and aquatic animals. 
 There was a difficulty, in fact, in accounting for the 
 transmission of odour through air and water, because 
 odour 1 was held to be a vaporous exhalation eliminated 
 by fire ; and the " special organ of smell was said to be 
 located about the brain*" the coldest of all parts of the 
 body, in order that the exhalation might there be con- 
 densed and made productive of smell. Thus, it might 
 seem to be irreconcilable with odour, that it should be 
 transmissible in air or water, and this may have led to 
 the hypothesis of a modified condition of the elements 
 for smell. 
 
 Note 8, p. 97. But neitfter man nor animals which 
 breatJte, &c.] The term in the text (avairvet), like our 
 own term breathing, is expressive both of inspiration 
 and expiration, whereas it is evident that the sense of 
 the passage requires the former process only. And yet 
 
 1 De Sensu et Sens. II. 19, 20. 
 
 2 De Part. Animalm, u. 7.
 
 272 NOTES. [BK. n. 
 
 elsewhere l , Aristotle, in his criticism of the theory adopted 
 by Diogenes and Anaxagoras to account for the respira- 
 tion of fishes, has clearly distinguished the one from the 
 other. He objected also to Timseus and some others who 
 had maintained that expiration must precede the other. 
 Enough, however, that he perceived, although unac- 
 quainted with the parts on which odours impinge, or the 
 organ by which they are made sensible, that they could 
 gain access to the sense only through inspiration. 
 
 CHAPTER VIII. 
 
 Note 1, p. 100. Sound of the actual kind is tJie, &c.] 
 As sound is the result of percussion, the passage implies 
 something to be percussed, as well as something in which 
 that which percusses is to move ; but what that some- 
 thing is in which percussion is to be made is not explained. 
 Some commentators, as Simplicius, have considered the 
 words ev TIVI to imply, " the air which is interposed 
 between the sonorous body and the sense," and which, 
 but for the contradictory opinions of that age with 
 respect to the air, might be at once accepted as its 
 meaning ; and even taken as some special medium, as has 
 been suggested, it still may signify a, body of air. We 
 1 De Respiraticme, 2. 3.
 
 CH. VIII.] NOTES. 273 
 
 may consider the voice, Plato 1 observes, as percussion 
 (sound, that is,) transmitted, by the air, through the ears, 
 brain and blood, to the sentient principle. But as the 
 nature and properties of the air were then, from the 
 want of experimental science, unknown, they were avail- 
 able for any hypothesis ; and yet there is evidence that 
 Aristotle, not to add Plato, did regard the air as essential 
 to sound and voice. Aristotle 2 , while agreeing with most 
 philosophers in ranking air among the four elements, "sees 
 a difficulty in determining what its nature may be in the 
 universe around the earth, or what its order in relation to 
 the other elements of bodies." He was aware of the air 
 holding water in solution, and observes that, whether 
 water be or be not produced, equally, from the whole air, 
 that which is around the earth must be not air only but 
 vapour, which is again to be condensed and become 
 water. Thus, " we maintain," he adds, " that fire and air, 
 water and earth are producible out of one another, and 
 that each of them is present, in potentiality, in each of 
 the others ; as is the case with all bodies, which have 
 a base into which each of them is ultimately reducible." 
 He has distinguished the air we inspire from that which 
 we send forth (eWe'jUTeii/) and to which he has given a 
 specific appellation (TO irvev^a) ; but owing to the diffi- 
 culty of determining either its nature or its office, 
 (although it is the subject of a special 3 treatise,) no 
 
 1 Timceus, 67 B. a Meteorologica, I. 3. 3. i. 
 
 3 irepl Trvev/j.a.Tos. 
 
 IS
 
 274 NOTES. [BK. n. 
 
 unexceptionable equivalent for it can be offered. These 
 quotations shew, amid many suggestive observations, that 
 knowledge concerning the air was then very unsettled ; 
 and yet they prove, it may be assumed, that air was 
 implied in the passage referred to. 
 
 Note 2, p. 101. An eclw is produced w/tenever, &c."j 
 This passage is obscure, both from its elliptical wording 
 and the want of adequate exemplification ; but, in 
 attributing to the air elasticity and capability of being 
 reflected, it seems to suggest that the atmosphere only is 
 the cause of sound and, therefore, of echoes. So, accord- 
 ing to modern science 1 , "an echo is sound reflected from 
 a distant surface and repeated to the ear ; although 
 several other conditions are required for its production." 
 In another treatise 2 , it is assumed that reflexion of the air 
 (/' araicA.atrtt) is the immediate cause of an echo; and 
 since an echo is reflexion, "must there not be, for its 
 production, air confined, impacted and communicating, as 
 one mass, with that which is to be reflected?" But an 
 echo, whether or not audible, ought, as the text states, 
 looking at the properties of the air, to be a constant 
 occurrence ; for as light is continually reflected from 
 bodies, and thereby casting shadows by which light 
 is distinguished, so sound, owing to the air's elasticity, 
 must be often reflected and, therefore, repeated, in varying 
 degrees of intensity, according to the nature of the surface 
 on which it may have impinged. That age, in fine, wa.s 
 1 Brande's Hist, of Science. a Problemota, XI. 8.
 
 CH. VIII.] NOTES. 275 
 
 acquainted with several of the properties of the air, but, 
 as they had not been tested experimentally, its acquaint- 
 ance with them was but conjectural, and could lead to no 
 positive inference ; it was reserved for modern science to 
 ascertain what the air is, and what its properties in rela- 
 tion to the world, its productions and inhabitants. 
 
 Note 3, p. 101. A void is rightly said, &c.] It would 
 be difficult even to conjecture what could have been 
 meant by a void in that age ; for although it had been 
 perceived 1 , it may be but obscurely, that the air rises by 
 fire (heat) to the upper regions and becomes ether, (as in 
 the Timceus, expiration is accounted for by the rising up 
 from within of the heated breath,) yet it is not to be 
 supposed that rarefaction was an admitted property of 
 the air, or that any condition like rarefaction was implied 
 in the void. Aristotle* observes, upon this topic, that, 
 "according to some philosophers, a plenum is a space or 
 vessel when full, and a vacuum or void is the same when 
 empty, thus making, as he says, the plenum to be identical 
 with the vacuum and space, excepting in conditions of 
 relation." In all this it is evident that no account was taken 
 of the air ; and he objects to Anaxagoras, (who had shewn, 
 experimentally, that the air is substance of some kind,) that 
 he argues against what had never been contended for the 
 advocates for a void maintain, he says, that it is a space 
 in which there is no tangible body, and, holding every 
 
 1 Meteoroloyica, II. i. 
 8 Xat. AutcuU. iv. 6. I. 
 
 182
 
 276 NOTES. [BK. n. 
 
 thing to be corporeal, they consider that only to be a void 
 in which there is absolutely nothing ; so that it can be to 
 no purpose to shew that the air is something. This 
 epitome shews sufficiently how widely apart from one 
 another are the antient and modern significations of a 
 void, since it now implies such a rarefaction of the air as 
 can be obtained through the air-pump; and, as rarefaction 
 cannot be carried beyond 300 times, no proof can be 
 afforded of the possible existence of a void. Aristotle 1 
 objects to those who maintained that the void is identical 
 with any space filled with air, " for, if the air be driven 
 out, the space will clearly, he observes, be a void, in a 
 stricter sense than it was, since it will no longer be full 
 of air." But it would be foreign to the purport of these 
 notes to inquire further into the opinions of that age ; 
 it may be inferred, however, from what has been adduced, 
 that Aristotle, although he refused corporeity to the air, 
 was not a very consistent supporter either of the plenum 
 or vacuum. 
 
 Note 4, p. 102. Every sonorous body, <kc.] This 
 passage is a summary of all that physiology has now to 
 offer upon sound and hearing ; but although it might 
 have been surmised that sound is vibration of the air, 
 caused by a sonorous body and conveyed, by successive 
 undulations, to the organ of hearing, yet, as the internal 
 ear was then unknown, it is a surprising assumption that 
 air must be contained within the organ, in order that the 
 1 Topica, vn. i. ii.
 
 CH. VIII.] NOTES. 277 
 
 vibration may be communicated to the sense. Aristotle 
 may perhaps have been led, notwithstanding the unstable 
 opinions of his age upon the air, to conclude that, as 
 sound " is present in the air," air must be connected with 
 the hearing, and, if so, be contained, naturally, within its 
 organ. The succeeding passages hardly admit of comment, 
 on account of their evident want of anatomical know- 
 ledge ; but they prove that the tympanic membrane had 
 been made out, as also that it may be so injured, as to 
 admit fluid from without into the ear. And this disease 
 of the membrane is aptly compared to ulceration and 
 consequent opacity of the eye's membrane, (the cornea,) 
 whereby the rays of light are precluded from entering 
 the eye and producing vision. 
 
 Note 5, p. 102. But proof is afforded, &c.] This 
 somewhat puerile experiment is still extant. It seems 
 strange that the very obvious cause of this phenomenon 
 did not occur to one who had surmised, without ana- 
 tomical proof, that there is air within the tympanum ; it 
 had escaped Aristotle, besides, that, in a former passage, 
 he had made the air which is immured vnthin the ear to 
 be immovable. 
 
 Note 6, p. 104. The voice is a sound, <fec.] This 
 passage is a clear definition of the voice, and it points, 
 although indistinctly, to the parts and functions concerned 
 in its formation. The voice ' is said to be different from 
 sound, and speech to be different from either; and, as 
 1 Hist. Animalm, iv. 9. r.
 
 278 NOTES. [BK. n. 
 
 speech can be produced by no other part than the pharynx, 
 those creatures only can speak which have lungs, as speech 
 is the articulation of the voice by the tongue. Where- 
 fore, the voice and larynx send forth vowels, the tongue 
 and lips consonants, and these together make up speech. 
 So, too l , Cuvier says, that " man alone among animals can 
 articulate sounds, owing probably to the form of his 
 mouth and the mobility of his lips." The 2 pharynx, so 
 called, and trachea, are of cai*tilaginous nature, and this 
 because they are for the sake of the voice as well as 
 breathing ; and it is necessary that that, which is to give 
 out sound, should have firmness as well as smoothness. 
 But the larynx and pharynx are here alluded to as if 
 they were one and the same organ, and it may be, that 
 owing to the complicity of the parts and their multiplied 
 relations to one another, they were then so considered ; 
 but yet passages 3 might be cited, which seem to shew that 
 they were known, both by function and position, to 
 be different organs. 
 
 Note 7, p. 105. Nature employs, simultaneously, the air, 
 &c.] It was assumed by the physiologists of that and, 
 indeed, many subsequent ages, that the office of respira- 
 tion is merely to cool the blood, or rather to temper its 
 heat, which was supposed to be constantly tending to an 
 excess incompatible with life. In modern times, on the 
 
 1 Anatomic Comp. t. I. 15. 
 8 De Part, Animalm, vn. 3. 5. 
 3 Ibid. ii. 3. 9 ; in. 3. i.
 
 CH. VIII.] NOTES. 279 
 
 contrary, the action of the air which is inspired upon the 
 venous blood has been by some regarded as a process of 
 combustion, and the source, through combustion, of the 
 special temperature which characterises all organised and 
 living bodies. Respiration is said, by Grant 1 , to be 
 essential to the constitution of animal bodies ; for by this 
 function " the vital fluids are purified and replenished, the 
 muscular system is furnished with its capability of action, 
 and the high temperature of the mammalia is preserved 
 in every condition of the surrounding element." 
 
 Note 8, p. 106. As proof of which we are, unable, <fec.] 
 The meaning of this passage, owing in part to the 
 unsettled knowledge of that age, is by no means evident ; 
 but it can be readily admitted, that the act of holding 
 the breath must set in motion, disturb, that is, the air 
 which has been inspired, and produce coughing rather 
 than articulation. The French commentator makes the 
 text (mvet xai TOVTO) to imply " disturbance of the 
 function;" Trendelenburg, however, sanctions the version 
 here given. It will be apparent, from what has been 
 adduced, that the word pharynx (of fishes) should have 
 been larynx, for this, being the upper part of the trachea, 
 is the tube which conveys air to the lungs, as the other, 
 being the upper part of the cesophagus, is the tube 
 which conveys food to the stomach ; and all fishes have a 
 pharynx, of course, but, as they do not breathe, they are 
 without a larynx. 
 
 1 Outlines, p. 592.
 
 280 NOTES. [BK. u. 
 
 CHAPTER IX. 
 
 Note 1, p. 109. And there seems to be an analogy, 
 <fec.] Aristotle \ in thus making Touch superior to, and 
 more influential than any other sense, (for it is the most 
 perfect, he observes, of man's senses, although with respect 
 to some others he is inferior to many animals,) is sup- 
 ported by Cuvier 2 , who says, "that Touch is the most 
 important of all the senses, and that its several degrees of 
 perfection exercise a surprising influence over the nature 
 of different animals ; and that of all the vertebrata man 
 has the most perfect Touch." It is difficult to attach a 
 sense to the term hard or soft applied to flesh, which, 
 by anatomical 3 description, corresponds with the muscular 
 substance of the body ; but man is said to have softer 
 flesh than any animal 4 , and on this account, through the 
 delicacy of his sense of Touch, to be of all creatures the 
 most intelligent. It is presumable that Aristotle was led 
 to suppose, from this sense being spread, so to say, like 
 the muscular substance, over the surface of the body, that 
 its organ lies somewhere in or beneath the flesh, and thus 
 to have concluded that a relative hardness or density of 
 that substance, by impeding tangible impressions, may be 
 
 1 Hist. Animalm, I. 15. 14. * Anat. Comp. t. ni. 569. 
 
 3 Hist. Animalm, in. 16. r. 4 De Part. n. 16. 16.
 
 CH. IX.] NOTES. 2S1 
 
 the cause of, or concomitant with dulness of the faculties. 
 The nervous system was then unknown, and Aristotle, so 
 fond of analogies, might readily suppose that the Touch 
 had, like other senses, its appointed organism ; and, if 
 there were such an organ, that it is extended over the 
 body, and thus must be in or beneath the flesh. The 
 Taste, as being a modification of Touch, was said to be 
 more delicate in man than animals. 
 
 Note 2, p. 110. There is a close analogy^ A similar 
 observation is made in the following chapter, and, besides 
 bringing sentient perceptions under some general law, it 
 was, probably, intended to shew that colour, sound, and 
 odour, although inappreciable by our senses, may still be 
 present. It shews, in fact, that our senses, being limited 
 in their capacity of perception, are not to be relied upon 
 when impressions are very greatly in excess or propor- 
 tionally faint. 
 
 Note 3, p. 111. Tlie smell is perceptive.] "That fishes 
 smell," Aristotle 1 observes, "is shewn in their being taken 
 by baits which have the particular odour, foul or grateful, 
 to which they are attached." But modern science has, of 
 course, determined both the seat and the structure of the 
 olfactory organ in fishes ; and shewn " how it is protected 
 from the violent and incessant action of the currents of 
 water required for respiration." Sanguineous* creatures 
 are all such as have red blood, and insanguineous, those 
 which, in place of red blood, have a pale bluish fluid 
 1 Hist. Animalm, TV. 8. 19. J Ibid. I. 4. 3.
 
 NOTES. [BK. n. 
 
 circulating in their veins. These last include "insects, 
 molluscs, Crustacea, and creatures with more than four 
 
 Note 4, pi 111. And htnce Ae dijflmlty of detcr- 
 iMjy, ic.] If the site amd structure of the olfactory 
 sense, in the lower forms of life, are still somewhat con- 
 jectural, it may well be supposed that the smell in non- 
 breathing animals was, in that age, although seen to be a 
 feet, inexplicable. But yet, although anatomy could not 
 then determine the seat of the sense, it might have been 
 conjectured that, as such creatures are obviously affected 
 by odours, there must be some other inlet for them than 
 that through which impression is made upon animals ; 
 and the detection of this mode of perception, would have 
 been another instance of homologous physiology. Aris- 
 totle 1 , following Plato, placed the seat of the smell and 
 other senses in the neighbourhood of the heart ; but 
 " the organ was said to be located, suitably, between the 
 eyes." 
 
 Note 5, p. 1 12. Tke olfactory organ in man, appear* 
 to differ, <fcc.] The analogy is obviously faulty, as it 
 seems to imply that the olfactory, like the respiratory 
 organs, are furnished with a cover, by the raising of which 
 odours gain access to the sense ; or rather, owing to the 
 intricacy of the parts and imperfect anatomical know- 
 ledge, the epiglottis has been associated with the velum 
 and posterior fauces. It could answer no purpose, then, 
 1 De Part. Animalm, n. 30. 9. 17.
 
 CH. IX.] NOTES. 283 
 
 to inquire, as some have, what animals have an operculum 
 for the smell, of that kind ? or what mean those veins 
 and pores? As although the operculum, that is, the 
 epiglottis, was known to be protective of the larynx and, 
 therefore, the respiratory organs, the relations of the 
 larynx with the parts associated with it had not been 
 made out ; and the veins and pores refer, probably, to the 
 bronchi and vessels within the chest. 
 
 Note 6, p. 112. In fine, odour is derived, <fec.] Aris- 
 totle here differs from Plato, who held that odorous 
 particles are in a state rather of fluidity ; and Cuvier ' 
 says, that " the organ of smell is moistened with abundant 
 viscosity, which arrests the odorous particles contained in 
 air or water ; as fishes are sensible of odours. But odour, 
 being regarded as exhalation, was assumed to be of fiery 
 nature and, therefore, like the element, dry, and this 
 required, for the conformity of the hypothesis of like 
 upon like, that the organ of the sense, when in potenti- 
 ality, should be also dry, and so, in due relation to 
 odour. 
 
 1 Anal. Comparee, 15* kfon.
 
 284 NOTES. [BK. n. 
 
 CHAPTER X. 
 
 Note 1, p. 114. Colour, however, is not thus made 
 visible.] The opinion here objected to originated with 
 Democritus. Aristotle 1 held it to be absurd to suppose 
 that colour and vision could be a process of emanation 
 from the eyes ; for colour produces sensation, he observes, 
 not by emanation but, by contact, and so it is better, at 
 once, to admit that vision is produced by the action of the 
 medium. There are 2 , it is said, seven distinctions of colour 
 and as many of savour ; and in another work 3 seven 
 vowels, seven pleiads, and seven chords. 
 
 Note 2, p. 114. No object, however, which is without 
 humidity.] This is little more than a repetition of what 
 had been said concerning sapid substances. Aristotle 4 
 seems to have adopted a theory, derived from mechanics, 
 for explaining the solubility of objects Whence comes it, 
 he asks, that an earth is both melted and moistened by 
 fluid (KCLI TtjKeTai KOI reyyerai) while soda (TO Be v'npov) is 
 melted but not moistened ? The answer is, because there 
 are pores throughout the soda which cause its parts to 
 be, at once, separated by the fluid ; while the pores in 
 
 1 De Sensu et Sens. 3. 15. 3 De Sensu et Sens. 4. 18. 
 
 3 Metapkysica, xm. 6. 5. 4 De Meteorol. iv. 9. 4.
 
 CH. X.] NOTES. 285 
 
 the earth are in alternate rows, so that the influence of 
 the fluid, in whatever way it may gain access, cannot but 
 be different. 
 
 Note 3, p. 114. As vision is perceptive, &c.] The 
 argument here is interrupted and obscured by parentheti- 
 cal explanations; but the purport is, that the senses are 
 the sole judges of sentient impressions through all their 
 degrees of intensity, and that, as sensibility is a mean, 
 they cannot discriminate such as are far above or below 
 the allotted medial standard. There is a seeming discre- 
 pance, however, in employing the term invisible as ana- 
 logous to impossible on other subjects, as vision is not 
 altogether lost in any darkness; but a creature without 
 feet could not continue its existence, nor a fruit without 
 the kernel continue its species. 
 
 Note 4, p. 115. The impotable as well as the potable, 
 <fec.] The impotable implies, of course, whatever is neither 
 moist nor capable of becoming moist, and every such sub- 
 stance must, necessarily, pain be very disagreeable to, that 
 is and pervert the Taste. All these passages, however, 
 while proving that moisture is required for savour, point to 
 a want of knowledge of the salivary and mucous glands 
 which were yet to be discovered. But over and above the 
 due conditions of moisture, there was still required the 
 knowledge of the nervous sysbem to account for the many 
 perversions of Taste which are manifested, both in sick 
 and well ; and manifested, at times, without any apparent 
 cause. It will occur to many, besides, how differently the
 
 286 NOTES. [BK. n. 
 
 Taste is affected by the same substance, as sugar for in- 
 stance, in different persons, and even, at times, in the 
 same person. 
 
 Note 5, p. 116. Kinds of savour are like shades of 
 colour, &c.] There must ever be difficulty in fixing 
 upon terms for savours or other sentient qualities, and 
 still greater difficulty in settling what are the exact 
 equivalents for such terms in another, and that not 
 a cognate tongue ; for although some savours, as bitter 
 and sweet, may be supposed to have an universal accep- 
 tation, there are others which, being far less definite, 
 are subject to variation, according to climate and race. 
 So that, with the exception of bitter and sweet, it can 
 hardly be pretended that the other terms, as oily, pungent, 
 rough, astringent, <fec., are perfect representatives of those 
 in the text. 
 
 Note 6, p. 116. In fine tJie sapid sense, &c.] This 
 passage does but repeat what has been already insisted 
 upon, that the sense, in potentiality, that is, when inactive, 
 is identical with that which is to act upon it; but that, 
 having been acted upon, it is brought into the state of 
 reality, and then becomes perceptive of the qualities of the 
 excitant.
 
 CH. XI.] NOTES. 287 
 
 CHAPTER XI. 
 
 Note 1, p. 118. Each sense seems to be perceptive, 
 <tc.] This passage seems to imply that all sentient im- 
 pressions may, in a strict sense, be tangible impressions. 
 Aristotle 1 , in another treatise, observes that sentient 
 bodies are bodies sensible of tangible impressions, and that 
 tangible impressions only have contraries, which, in kind, 
 are specific and causative. And, "thus, neither white- 
 ness and blackness, sweetness and bitterness, or any 
 other contraries save those alluded to, can form element- 
 ary distinctions." All which implies, perhaps, that the 
 Touch is either the origin of or coeval with animal 
 existence ; and that the other senses are but for the 
 higher forms of being. The properties, besides, which 
 are attributed, so to say, to the Touch are, in con- 
 tradistinction to those of the organs of relation, mainly 
 concerned in the changes continually going on in inert 
 bodies ; and this consideration may have, in part, con- 
 tributed to the speculative opinion just quoted. 
 
 Note 2, p. 120. It may be a question whether as all 
 bodies, <fec.] This is an argument to prove that, as there 
 cannot be absolute contact of bodies in water, so neither 
 1 De Gen. el Corr. n. i. i.
 
 288 NOTES. [BK. n. 
 
 can there be in air ; and thus that the flesh can be only 
 the medium for tangible impressions that there must 
 ever be air interposed, that is, between the object and the 
 surface of the body. It may seem now to be supereroga- 
 tory, but, as the atmosphere had not then been experi- 
 mentally investigated, crude and contrary opinions, as 
 might be supposed, were entertained concerning it, and 
 its manifold relations 1 . The term "third magnitude" is 
 derived from, or associated with the Pythagorean doc- 
 trine of number as of magnitude, continuous length is 
 referrible to one, breadth to two, and depth to three ; and, 
 thus, depth is the " third degree " of or relation to 
 magnitude. 
 
 Note 3, p. 122. But tangible differ from visible, &c.] 
 "It will be evident that whatever may, in these passages, 
 be erroneous, is traceable to the flesh being regarded as 
 the sense or the medium for the sense of Touch, as, in 
 either case, the Touch, differing from every other sense, 
 would, from what has been maintained, require two media. 
 There seems to be something like forgetfulness in with- 
 drawing, so to say, the medium in the example given of 
 tangible impression, and supposing that the man and his 
 shield can be simultaneously transfixed. 
 
 Note 4, p. 122. The different states of the body as a 
 
 body, &c.] As the Touch was regarded as a primal or 
 
 elementary sense, so the qualities, of which it is perceptive, 
 
 (as hot and cold, dry and moist, <fec.) were also regarded 
 
 1 Metaphysica, IV. 13. i.
 
 CH. XI.] NOTES. 289 
 
 as elementary qualities ; and distinguished from visual or 
 sonorous impressions, by being necessary to animal exist- 
 ence. It is uncertain whether the work "upon the 
 Elements" here alluded to was a distinct work, or a 
 chapter in one of the treatises which have been cited ; 
 but the question is of little consequence, and foreign, 
 besides, to the purpose of these notes. 
 
 Note 5, p. 123. TJie mean, in fact, is critical, &c.] This 
 is a transfer, so to say, of moral to physical relations. 
 "Whatever is continuous and divisible comprehends," Aris- 
 totle ' says, " the three terms, more, less, and equal, which 
 all bear a relation either to the thing itself or to our- 
 selves ; for the equal is a given mean between excess and 
 deficiency. Now, the mean implies that which is equi- 
 distant from either of the extremes, and it is one and the 
 same in all material conditions ; but the mean, in relation 
 to us, implies a state in which there is neither excess nor 
 deficiency." Thus, temperance nourishes and preserves 
 the body, while excess or deficiency of food and drink 
 tends to destroy it. Moderate exercise increases, while 
 immoderate or insufficient exercise impairs the strength ; 
 and so for other conditions which are readily adducible. 
 
 Note 6, p. 123. As vision was said to be in tome 
 sense, &c.] The passage is obscure, but it seems to repeat 
 a former observation, that, as the senses can judge of sen- 
 tient properties only in their mediate state, the terms 
 invisible and intangible are, strictly speaking, incorrect 
 1 Ethica Nicom. II. 6. 5. 
 
 19
 
 290 NOTES. [BK. n. 
 
 and inapplicable. " The air ', moving in currents, was said 
 to be wind ; " and, when at rest, it was supposed, like 
 all else, when either in excess or deficiency, to be with- 
 drawn from sentient perception. 
 
 CHAPTER XII. 
 
 Note 1, p. 125. It is the primal organ, &c.] Philo- 
 ponus and Simplicius, according to some commentators, 
 believed that the "mind" was the organ or principle 
 here alluded to ; but Saint Hilaire is disposed to regard 
 it as "sensibility, irrespective of any thinking principle." 
 Trendelenburg inquires, what means the term ' primal ' 
 quid hoc y>irror? He seems, however, to consider the 
 mind as the special seat of the faculty in question " quod 
 primum dicitur, id tacite mentem spectari videtur, quse 
 propria est hujus facultatis sedes ; et ea prima quidem, 
 si ab intimo fonte projidscaris." It may, however, with 
 some confidence, be assumed that this primal organ points, 
 suggestively, to the brain ; for it evidently implies a cen- 
 tral organ connected with each of the senses, and receptive 
 of all sentient impressions. Thus, such an organ, -while 
 receptive of form, may well be said to be identical with 
 the object ; and yet, seeing how opposed are the manifes- 
 
 1 Jfeteoroloffica, L 13. 2.
 
 CH. XII.] NOTES. 291 
 
 tations of the sensibility to the properties of matter, not 
 be so, in an absolute sense. The organ, like the brain, in 
 fact, being perceptive of forms and properties through 
 the senses, is identified, pro tanto, with objects ; although 
 it cannot but differ from them absolutely, in mode of 
 being, that is in essence. 
 
 Note 2, p. 126. But why do not plants feel, &c.] The 
 answer to this question, by assigning to the organ a defi- 
 nite locality and function, seems to lend support to the 
 explanation offered in the foregoing note. The passage 
 in the original TO /*>/ e^eii/ /xe<roT/Ta is rendered too 
 freely, perhaps, in this version, as mediate faculty ; but 
 the French "qualite moyenne" is to the same purport. 
 The Latin is, " neque id medium, tanquam mensuram et 
 modum habent, quo sensus quasi judicant." It may be 
 that as Aristotle had refused, so to say, sensibility to the 
 brain, he found himself constrained, in order to explain 
 the function of the senses and their power of recalling 
 images, to adopt a central organ, to be as well the source 
 of sensibility as the sensorium or store-house, for the 
 mind and memory. He had been led, in fact, to regard 
 the brain as insentient, because of its not imparting 
 sensation when touched, and as subsidiary to the respira- 
 tion for tempering the internal heat, because of its appa- 
 rent coldness. All this was the settled conviction of this 
 great man ; Democritus, however, seems to have perceived 
 that the brain is either the organ or the seat of sensi- 
 bility, although the opinion was not generally admitted. 
 
 192
 
 292 NOTES. [BK. u. 
 
 Plato agreed with physiologists in making the seat of 
 the senses to be the liver and neighbourhood of the heart, 
 but he differed from Aristotle in believing the brain to be 
 continuous with the spinal chord, and to be the source of 
 the intellectual faculties. He held the brain, in fact, to be 
 the seat if not the source of the higher faculties, while he 
 assigned the appetites and coarser passions to the viscera. 
 Hippocrates ', who lived some years before him, assigns to 
 the brain the guardianship of the mind, and makes it to 
 be not only the first percipient of all the changes of the 
 seasons, but also the source and seat of all the more deadly 
 and complicated maladies. 
 
 Note 3, p. 126. It may be questioned, &c.j The 
 argument, in these passages, is to account for the changes 
 which are constantly going on in bodies, and for which 
 that age could assign no adequate cause ; but still it was 
 perceived that tangible and sapid qualities (hot and cold, 
 wet and dry, acid, saline, astringent, and others) must be 
 the agents principally concerned in their production. 
 Thus, although neither light nor darkness, sound nor 
 odour, can act upon bodies, yet something present with 
 them may, and this seems to point, suggestively, to those 
 imponderable and invisible forces (heat, magnetism, elec- 
 tricity, &c.), for which, as yet, even " no plausible theory 
 has been adopted." 
 
 Note 4, p. 126. But all bodies are not impi-essionable, 
 &c.] These passages are very obscure ; but their purport 
 1 Epistola, T. in. 824 ; T. i. 614.
 
 CH. XII.] NOTES. 293 
 
 seems to be, that odour and sound can act only upon such 
 bodies as, like the air and water, are neither limited 
 nor stationary are made to be the carriers, as it we're, 
 of delicate emanations and vibrations to sentient organs. 
 Thus, it is added, the air, having been impressed by odour, 
 readily gives it out, and, then, through the smell, becomes 
 perceptible to the sentient being. But neither odour nor 
 sound, as such, can in aught contribute to the changes to 
 which all inert bodies are subject ; and the actions of 
 sound and odour, therefore, seem to be limited to sen- 
 tient, that is, living properties. This may be to us a 
 truism, but it must be recollected that even to Aristotle 
 the olfactory passages were but imperfectly known ; that 
 the opinions upon the Atmosphere were hypothetical ; and 
 that the processes by which changes are wrought in 
 inert matter were still to be detected.
 
 BOOK THE THIKD. 
 
 CHAPTER I. 
 
 Note 1, p. 131. The sentient organs, however, are con- 
 stituted, &c.] The senses were formed, according to that 
 age, from the elements as the hearing from air, and the 
 eye, which alone was supposed to have a special organ, 
 from the purest part of the fluid secreted by the brain ; and 
 vision is the result, according to Aristotle, of refraction. 
 Thus, Democritus ' was held to be right in saying that the 
 eye is water but to be wrong in supposing vision to be 
 caused by reflection, (jo opav elvm Ttjv ^0a<r<i/) as vision 
 is, not in the eye but, in the percipient; for "vision is re- 
 fraction " (a'iaK\a<r<? jap TO irdBoi). Aristotle shews that, 
 according to the admitted doctrines, these two elements 
 only constitute the sentient organs of all animals which 
 are perfect ; and adds, as if to guard against a possible 
 objection, that the mole has eyes although they may not 
 be very apparent. It is then argued that, unless there is 
 some kind of body or mode of impression different from all 
 
 1 De Sensu et Sens. 2. 10.
 
 CH. I.] NOTES. 295 
 
 with which we are acquainted, no sense can be wanting; 
 and Cuvier 1 adopted a similar argument to prove that no 
 animal, unknown to Zoology, remains to be discovered. 
 
 Note 2, p. 132. And this ive are able to do, &c.] 
 This passage is elliptical and obscure ; but, as " the rela- 
 tive is too closely connected with the example something 
 sweet to admit of being separated," it may imply that the 
 sight may, by colour and refraction, determine the quality 
 of a particular fluid. But, as no sense can judge, excepting 
 indirectly, of compound qualities, the perception of such 
 is accidental, a kind of guess, that is, just as it would be 
 in the case of a fair individual, in the example of Cleon's 
 son. 
 
 Note 3, p. 133. The senses, however, do perceive casu- 
 ally, &c.] This passage remains, according to its wording, 
 unintelligible, notwithstanding the attention bestowed upon 
 it by commentators, because of the difficulty of attaching 
 any sense to the assumption, that the senses can become 
 as one. The comment " si unum et idem uno et eodem 
 tempore a diversis sensibus percipitur, ni sensus in unum 
 coalescunt," assumes but does not shew that the senses can 
 so coalesce, and then judge of impressions made upon them 
 individually. And thus here again is required a central 
 organ, the common origin of the perceptive power of the 
 senses, to which all impressions are to be referred and by 
 which they are to be compared; and such an organ is the 
 brain. But still, from the moment that we judge of more 
 1 Discours sur lea Revolutions de la terre, 66 67.
 
 296 NOTES. [BK. in. 
 
 than a simple impression or a single idea, there is liability 
 to error, as was observed and exemplified in the case of a 
 fluid, which, from being bitter and yellow, is at once 
 assumed to be bile because those are the known qualities 
 of that fluid. Many of our errors arise, no doubt, in like 
 manner, from our not sufficiently scrutinising the impres- 
 sions derived from external objects. 
 
 CHAPTER II. 
 
 Note 1, p. 135. It is then manifest that perception 
 &c.] This is a conclusion drawn from the reasoning 
 of a former chapter, and its purport is to shew that our 
 senses enable us to judge even of privative conditions, as 
 darkness and silence ; and, further, that, being receptive 
 of forms without matter, they can retain images, and so, 
 through the sensorium recall objects after their with- 
 drawal. 
 
 Note 2, p. 136. The action of the object of percep- 
 tion, &c.] It has been attempted, by some of the 
 ancient commentators, to annex this to the preceding 
 argument, and shew that, as sight must first be imbued 
 with colour, so the hearing must, in order to perceive 
 sounds, be first sensible of the actions of sonorous bodies. 
 But the more obvious signification, and which is equally 
 supported by the text, is, that there must be simultaneous-
 
 CH. II.] NOTES. 297 
 
 ness of action between the object and the sense, although 
 the modes of that action are as different as material are 
 from living properties. The succeeding passage is, by its 
 wording, obscure, but yet it admits of being elucidated 
 by the term on which its meaning chiefly depends ; for 
 hearing, when in potentiality, must involve both sound 
 (as without hearing there is no sound,) and hearing, in 
 reality, just as the Vital Principle must exist, innately 
 in the body in potentiality, but which, under genial 
 circumstances, is to be acted upon and made a reality ; 
 and thus, too, the power which impels may, itself, be 
 at rest. 
 
 Note 3, p. 136. But while for some senses tfiese two 
 states, &c.] It is scarcely possible, owing to the difficulty 
 of fixing upon synonyms, to make this passage clear to 
 the general reader the text instances two terms (\//o0>;- 
 <ri? KCCI tj ciKovo-i?), as potential conditions of sound and 
 hearing (-v|^o'0os KO.\ tj awtf), and it may be assumed that 
 they conveyed a modified signification of the action and 
 sensation, which another language, even were the meaning 
 quite evident, may fail in imparting. But even the 
 plastic Greek fails, in many instances, in discriminating, 
 without periphrasis, the two conditions ; for vision, 
 although potential, is still vision, nor has it any other 
 designation when made reality by colour, and this applies 
 equally to the taste ami savour. In this version, the 
 double condition of sound is rendered by sound and 
 sounding, that of the sense by hearing, and audition for
 
 298 NOTES. [BK. in. 
 
 want of a vernacular term ; the French version gives 
 them as " le son et la resonnance, et 1'acte de ce qui pent 
 entendre est Fouie ou audition." It is clear that hearing 
 and sound, and other senses and actions, in reality, must 
 coincide to eliminate sensation ; although this does not, 
 of course, apply, as the text observes, to the senses in 
 potentiality. And, hence, in this state, there are, for a 
 sentient being, no such qualities as white or black, bitter 
 or sweet, as they depend, for their reality, upon a given 
 condition of the sensibility, which depends again, in part, 
 upon the will. 
 
 Note 4, p. 137. If a, voice of any kind is harmony, 
 &c.] This deviation from the immediate subject of the 
 chapter, which was to prove that the five senses satisfy 
 all our wants as sentient creatures, and that, therefore, 
 there can be no other sense besides them, is, no doubt, 
 episodical, although it is annexed, by the extremes of 
 sounds, to the general argument upon sensibility. But 
 the phrase itself is by its wording obscure, and, by its 
 conclusion unsatisfactory, for it may not follow that, 
 because voice may be harmony and harmony proportion, 
 the hearing must be proportion also. It 1 has been 
 suggested that, by a slight change of position in the 
 words, and so, instead of the present wording, making 
 harmony, voice to be (el S* ;' <pwv^ (rv/icptovia vice el %rj o-uju- 
 (fxatiia (pwvti -m) of any kind, it might be assumed that 
 hearing should be harmony. Aristotle 2 , by allotting 
 1 Vide Trendel. Comment. a De Part. Animalm, iv. 9. i.
 
 CH. II.] NOTES. 299 
 
 " vowels and consonants, which constitute speech, to the 
 larynx, tongue and lips," seems, by this variety of sounds, 
 to consider voice as a kind of harmony ; and Cuvier says, 
 that all the modifications of sound which are expressible 
 by the letters of the alphabet, " take place in the mouth, 
 and depend on the relative mobility of the tongue, and 
 still more the lips, whence the perfection of man's speech 
 is derived." 
 
 Note 5, p. 138. But since we judge of white, sweet, 
 and each other, &c.] The only answer to this, as it was 
 to a former inquiry, is, that the brain is that general- 
 ising faculty, and that it fulfils all the conditions, however 
 enigmatically described, which are required in the text. 
 It is impossible to refuse to the brain the property of 
 receiving and comparing contrary impressions, simultane- 
 ously, and receiving them, therefore, in the words of the 
 text, as an indivisible principle, just as the mind can 
 compare opposite ideas ; and all the speculations upon 
 impulses and the divisibility and indivisibility of that 
 which is to perceive and judge only shew the want of a 
 central organ for the reception and comparison of indi- 
 vidual sensations. And many of these passages are 
 necessarily obscure, owing to their partaking of the 
 character of inquiry or suggestion, rather than didactic 
 statement ; but their obscurity may be, in part, seen 
 through by the introduction of that source of sensibility, 
 which is said, in the closing paragraph, to constitute 
 animal in contradistinction to mere vegetive life.
 
 300 NOTES. [BK. HI. 
 
 CHAPTER III. 
 
 Note 1, p. 142. Thus, t/ten the ancients affirm, &c.] 
 Parmenides, Anaxagoras, Empedocles and Democritus, 
 are cited by Aristotle 1 as maintaining the doctrine 
 alluded to in the text ; but as Homer 8 can hardly be 
 said in the passage quoted to have adopted it, there is 
 probably an error in the reference. The arguments of 
 these writers, in support of the doctrine, are derived from 
 the uncertain and varying nature of sentient impressions 
 which, as they depend upon individual organisms, cannot, 
 for the attainment of truth, be brought under any absolute 
 law. Thus, they held that it belongs not to the many 
 nor even the few to judge of truth, since the selfsame 
 fluid, when tasted, seems to some to be sweet, to others 
 bitter ; so that if all were sick or mad, and two or three 
 only well or sane, then these and not the others would 
 seem to be in that state. Many things, besides, appear 
 to have for many animals opposite qualities from what 
 they have for us; and even for the same individual, 
 similar substances do not always produce the same 
 sensation. So that it is uncertain which of these are true 
 or false, since these are neither more nor less true than 
 
 1 Metaphysica, III. 4. 8. 9. * Odyss. xvm. 135.
 
 CH. III.] NOTES. 301 
 
 those ; and this made Democritus say, that either nothing 
 is true, or else that truth is for us uncertain (alri\ov). 
 From their assuming, as a general proposition, that 
 reflection is sensation, they maintained that reflection 
 is change, and that the apparent, through sensation, is, of 
 necessity, true ; and it is from such conclusions, Aristotle 
 adds, that Empedocles and Democritus as well as their 
 followers became fettered by those opinions. For Em- 
 pedocles affirmed, that men, by changing their habit 
 (ef?) change also their judgment, " for man's wisdom is 
 enlarged," &c. ; and elsewhere he says, that " in so far as 
 men are capable of change, in so far they are capable of 
 forming different judgments." The opinion of Parmenides 
 is to the same purport ; and there is a recorded saying of 
 Anaxagoras to some of his followers, that "beings will 
 be to them such as they may suppose them to be." These 
 writers attribute the same opinion to Homer, (but it was 
 shewn in a former note that this reference is faulty,) 
 because he made " Hector, as if beside himself under the 
 blow, to lie thinking differently," (d\\o<f)poveovTa). But 
 it was incumbent upon these writers, as is observed in the 
 text, to have dwelt upon the liability to error to which 
 we are all ever subject through the senses; for if all 
 appearances are to be held as true, then the same impres- 
 sion may be at once true and false ; which is to admit an 
 impossibility. The doctrine, in fine, of this school, as 
 given in the text was, that the power by which animals 
 move is corporeal, and like to the faculty which thinks,
 
 302 NOTES. [BK. in. 
 
 as also that the faculty of conclusions (judgment) is 
 some form of sensibility ; and thus, it reduced, so to 
 say, the faculties of thought to sensual impressions and 
 conditions. 
 
 Note 2, p. 142. On which account, eitJier all appear- 
 ances, <fec.] This is a dilemma, as an objection to their 
 doctrine, in that, " either all appearances are, as they 
 maintain, necessarily true, or else (in opposition to their 
 dogma, that like is recognised by like,) there is recognition 
 by unlike;" and thus the error from contraries is made 
 identical with the knowledge of contraries. The objection 
 is then placed upon the obvious ground that, while 
 sensation is allotted to all creatures, reflection, which 
 implies reason, belongs but to few ; and next, as a general 
 argument, it shews that mental faculties, being derived 
 from other sources than feeling, cannot be identical with 
 sentient perceptions. 
 
 Note 3, p. 143. But it is manifest that imagination, 
 <kc.] The argument next proceeds to the subject of 
 imagination, and as has been well observed, it is thus 
 appropriately placed between sentient perceptions and 
 thoughts, " as imagination cannot be without senses, 
 or the mind without imagination." For " imagination 
 is not identical with sensation," Aristotle 1 observes, 
 and yet " it is called up either through thought or 
 through sensation." Imagination then, is neither sensa- 
 tion nor conception, as the former depends upon external 
 1 Metaphysica, in. 5. 23. De Motu Animalm, 8. 5.
 
 CH. III.] NOTES. 303 
 
 influences, and the latter, which is a result from reason- 
 ing, being true or false, is removed from the will ; but 
 imagination on the contrary, can be exercised how and 
 when we please. It is difficult either to represent 
 graphically the process here alluded to, or to determine 
 the precise import of the text ; and other versions seem 
 to be equally indefinite. The Latin is, "licet Hamque, 
 cum libet, fingere quicquid volumus, atque ante oculos 
 ponere, perinde atque ii faciunt qui, in artificiosse memorise 
 comparatis atque dispositis locis, imaginis fingunt atque 
 simulacra collocant," and the French, " et Ton peut s'en 
 mettre 1'objet devant les yeux, comme le pratiquent ceux 
 qui traduisent les choses en signes mnemoniques, et 
 inventent des symboles." Hence, an opinion, arrived at 
 by a chain of reasoning drawn from particulars which we 
 hold to be true, cannot but affect us differently from 
 imaginings which are of our own coining, and which we 
 know to be fictitious. A succeeding passage, which shews 
 that imagination cannot be opinion, is to the same purport 
 for, being derived from particulars, its issue is, so to 
 say, independent of us ; but imagination may be exercised 
 upon any combinations which the will may choose to 
 recalL 
 
 Note 4, p. 147. But the motion produced by the act, 
 &c.] The wording, by the act, is but an indifferent 
 representative of the original VTTO rfj<: cvepyeias, and yet 
 its exact signification, or its relation to the eWe/Ve^ia is 
 by no means obvious ; the phrase, besides, notwithstanding
 
 304 NOTES. [BK. in. 
 
 its repetitions, is still vague and obscure. It seems, 
 however, to embody former assertions that a single sen- 
 sation from a special organ, that is, must be true ; and 
 that there is room for fallacy when other qualities are added 
 to that sensation, and still more so when common pro- 
 perties, as motion, magnitude, or number, are, for ex- 
 planation, to be taken into the account. 
 
 Note 5, p. 147. And since vision is a sense, &c.] It 
 will be apparent that this passage depends, for its mean- 
 ing, upon etymology (j)avTa<ria. (fancy or imagination) 
 may be derived, if not from <a'oe, yet, from the same 
 root as 0a'o?, which probably is 0w? (light), as light is 
 essential to vision ; and 0a'oe may have formed (palvio, 
 which is an approximation to (pavraa-ia. The Latin 
 version is, " cum autem visus maxime sit sensus, hinc est 
 quod nomen imaginatio ab ipso lumine sumpsit, phan- 
 tasiaque dicitur, quia sine lumine visio fieri nequit." 
 Imagination or the mental perception of images, that is, 
 being regarded as an inward sight, and sight as the most 
 precious of the senses, was derived from the same root as 
 light, because light is essential to sight.
 
 CH. IV.] NOTES. 305 
 
 CHAPTER IV. 
 
 Note 1, p. 153. T/wre is a distinction between posi- 
 tive, &c.] All the passages, under this head, are obscure, 
 if not incomprehensible ; their purport seems to be whe- 
 ther the mind judges, by one and the same faculty, of 
 realities, (qualities, that is, perceived through the senses) 
 and realities viewed, abstractedly, in their essence. Thus, 
 the inquiry seems to be whether the mind is sensibility 
 or associated, so to say, with sensibility, or altogether 
 distinct from it ; whether the sentient perception which 
 is engaged upon particulars, can ever be capable of the 
 abstract reasoning which detects the essence of things, 
 and so generalises and groups them for universal laws. 
 This does not, however, apply, it is said, to all subjects, 
 as, with some, "the two states are identical;" and this 
 is the case with abstractions or immaterialities, which fall 
 within the province of the mind apart from sense. 
 
 Note 2, p. 153. Now, it is by tfte sensibility that we 
 judge, &c.] This phrase seems to allude to the then 
 admitted doctrine that the sense of Touch either is flesh or 
 in the flesh, and that it, therefore, directly or indirectly, is 
 perceptive of hot and cold, and other such qualities ; and 
 this assumed sentient property may have led to this com- 
 
 20
 
 306 NOTES. [BK. in. 
 
 plicated argument, which makes flesh to be rather an 
 abstract than a positive substance. Trendelenburg, in the 
 allusion to curved and straight lines, sees a reference to 
 Plato's opinions upon intellectual processes : " Sane Plato 
 actiones intellectus circulis primum recto, mox circinato 
 recurrentique interius comparat : Aristoteles linese expli- 
 catse et replicatse, sive porrectse et curvatse." It may, 
 however, be assumed that, whatever the figures or analo- 
 gies employed, the operations of the mind will still remain 
 as mysterious as those of the sensibility ; and, thus, that 
 all such inquiries are, as final causes, beyond our research 
 and, so far, unprofitable. 
 
 The Latin version of the phrase is, " Sensitiva igitur 
 parte calidum discernit et frigidum, quorum qusedam est 
 ratio caro, alia vero esse carnis discernit, aut separabile 
 aut se habente ad se ipsam perinde atque se habet cum 
 extensa fuerit linea flexa." That of the French, " Mais 
 c'est certainement par une autre faculte qui est separee, ou 
 qui du moins devient a elle-meme ce que la ligne brisee 
 est elle-mfeme aussi quand on la redresse, que nous 
 jugeons ce que signifie etre la chair." 
 
 Note 3, p. 154. But we have to consider why the 
 mind, <fec.] The chapter is closed rather abruptly with 
 this passage, which, by some, is said to be spurious ; but, 
 although obscure in its wording, it is in keeping with the 
 general tone of the inquiry and argument. The main 
 purpose of the inquiry is why, as every subject of thought, 
 in potentiality, is among material substances, the mind is
 
 CH. V.] NOTES. 307 
 
 not constantly thinking, just as it has been asked why 
 the sensibility, which is ever acted upon by external in- 
 fluences, is not constantly made percipient. The answer 
 seems to be, that the sensibility, being in potentiality, is 
 incapable of perception without the agency of external 
 influences, while the mind, being immaterial, is able to 
 judge of the relations of things, without being identified 
 with them; and thus, that, although every object, as a 
 subject of thought, may be said to belong to the mind, it 
 cannot belong to any one of them. It may well, however, 
 be said, with respect to this, among other passages of 
 this chapter, " est enim Aristotelis, liberum cogitationis 
 cursum sequi neque anxia perspicuitatis causa deflecti" 
 
 CHAPTER V. 
 
 Note 1, p. 156. As if it were a virtuality like light.'] The 
 original '? ef is TIC is ill represented by virtuality, and 
 yet neither habit, state, nor condition would represent 
 the agency of the mind as a realising principle ; as that 
 which can collect, compare, and so give reality, in gene- 
 ralisations, to perceptions received through the senses. 
 " Sicut colores expectant, ut appareant, (i. e. ut colorum 
 vice vere fungantur) ita sensuum notitiae et quidquid ad 
 intellectum patientem pertinet mentem agentem requirunt, 
 
 202
 
 308 _ NOTES. [BK. in. 
 
 ut omnes veritatis numeros habeant, et verse notioiiis vim 
 consequantur." 
 
 Note 2, p. 156. Knowledge in activity is identical 
 with, &c.] This passage seems to be the complement of 
 what had just been asserted, that the agent is ever more 
 influential than the subject, and the originating cause 
 than the matter ; for the intellect, in activity, may be 
 said to create, to identify with itself that is, the know- 
 ledge which it acquires concerning external things through 
 abstract reasoning. Knowledge pre-exists, however, as 
 has been said, in every well-constituted individual, be- 
 cause each is furnished, at birth, with faculties for 
 acquiring knowledge ; but yet it cannot strictly be said to 
 pre-exist, since it may, or may not be developed by edu- 
 cation or reflection ; as the mind, moreover, is impassive, 
 it is not impressionable, and cannot, therefore, be the seat 
 of memory. But what means the impressionable mind 
 which is perishable ? may it not be again said that, 
 suggestively, the brain is here implied ; since this organ 
 is the sensorium, the seat of memory, and dependent, 
 besides, like all other organs, upon life, for its functions 
 and its continuance.
 
 CE. VI.] NOTES. 309 
 
 CHAPTER VI. 
 
 Note 1, p. 159. In the way that Empedocles, &c.] The 
 passage cited in support of the above opinion is not very 
 apposite; for Empeclocles 1 , who had made "nature to be 
 nothing more than the combination of (yu <"<?) and change 
 among commingled particles," (attraction and repulsion, 
 in other words), is quoted by Aristotle * in the words, 
 " many heads of creatures without necks budded forth ;" 
 and, as if to turn against him, as it were, his own doc- 
 trine, it is added, " they were by affinity joined together." 
 This led Aristotle to the simile in the text, as Empedo- 
 cles 3 formed things in nature by the combination of 
 individual particles, so may the mind eliminate new by 
 the association of former or admitted ideas ; and as, in 
 the verse cited, head and neck lie dissevered, so, in the 
 idea of quantity, there is nothing in common between 
 the measure of the diagonal and the side of the square. 
 Thus, as there is no common measure for the diagonal 
 and the side of the square, they are, in so far, distinct ; 
 but although, in themselves, distinct, they can, in thought, 
 be combined and made one. " By diameter may be 
 
 1 De Gen. et Corr. i. i. 7. * De Ccdo, in. 2. 7. 
 
 3 Vide Trendel. Comment.
 
 310 NOTES. [BK. in. 
 
 understood the diagonal which divides the square into 
 two equal triangles ; or it may mean the diameter of the 
 circle which is incommensurate with the circumference." 
 In a word, it is by combination that error creeps into our 
 judgments, and falsifies our perceptions. 
 
 Note 2, p. 159. It is the mind, &c.] The question 
 of a fact, such as that in the example, is dependent 
 upon the brain rather than the mind, as that organ can 
 combine the individual notices obtained through the 
 senses ; but when the mind intervenes, so to say, and 
 judges from what is, of what was or is to be, there is 
 room for error. It is almost puerile to explain that the 
 assertion " something is not white " is not, necessarily, 
 fallacious ; and that, if the object be white, the fallacy 
 comes from the addition of the negative. The double 
 sense of indivisibility is to the same purport ; extension 
 is clearly divisible, and, therefore, divisibility is made, 
 actually, apparent as a fact ; but the mind can realise to 
 itself extension without parts, as indivisible, that is, and 
 in potentiality. 
 
 Note 3, p. 160. It may not then be said, &c.] In 
 this version, the term mind is used, and in another, " in- 
 telligence," (which is its synonym), as that which thinks, 
 (rl woei), but the text does not so specify it ; and any 
 allusion to halves would but ill-accord with the notion of 
 homogeneity and impassibility assigned to the thinking 
 principle. But no theory which could be framed of the 
 mind would aid in explaining the train of reasoning
 
 CH. VII.] NOTES. 311 
 
 here ; for, independently of the abstruse nature of all 
 mental processes, there is, evidently about it, confusion, 
 arising from the assumption of a something associated 
 with sensibility, which the brain only could rectify. 
 
 Note 4, p. 160. The point and every analogous divi- 
 sion, &c.] With respect to quantity l , in relation to indi- 
 visibility, "a point which has position, (KO! Qiaiv e%ov 
 <rT7/ui;') is indivisible, but a line is divisible in one, surface 
 in two, and body in several directions;" and by privation 
 is implied that the point is without length, depth, or 
 breadth ; the line without either breadth or depth ; and 
 the surface without depth. It is obvious, from what has 
 been said, that every affirmation or negation must, as 
 depending upon sentient impressions, be either true or 
 false ; but that the judgment, when deciding upon essen- 
 tial or abiding qualities, may be true, and that, when 
 drawing its inferences from accidental qualities or rela- 
 tions of bodies, it may be erroneous. 
 
 CHAPTER YIL 
 
 Note 1, p. 165. Images belong, naturally, to the think- 
 ing principle, <kc.] This very suggestive comparison 
 between intellectual and sentient perceptions, seems, even 
 in the absence of knowledge of the brain, to assume that 
 1 Metaphysica, iv. 6. 24.
 
 312 NOTES. [BK. in. 
 
 practical thoughts must be derived from the senses, and, 
 therefore, through a sensorium ; and as impressions may 
 be genial or otherwise, the faculties suggest pursuit or 
 flight. The practical mind, in fact, never thinks without 
 an image which acts, in its turn, so to say, upon it, as the 
 air, which has been impressed by colour, does upon the 
 pupil and the pupil upon something else (that is, the 
 retina), and so sound upon the hearing ; but the last 
 term, that is, the visual or auditory sense, is one, as the 
 mean or medium, however modified in condition, is one. 
 It will be evident, with but little consideration, that the 
 obscurity which is palpable in the succeeding passages is 
 occasioned by the absence of the brain, and can be cleared 
 away only by its introduction; and that, with it, the 
 analogies of unit and limit acquire some kind of signifi- 
 cation. 
 
 Note 2, p. 166. Thus tlie cogitative faculty dwells, 
 &c.] Aristotle seems here to consider images or thoughts, 
 present in memory, as necessary to ratiocination, and he 
 has elsewhere said that an individual without senses 
 could neither learn nor understand ; but he is evidently 
 alluding to a higher faculty than the sensibility, and 
 which is able, by abstract reasoning, to draw, from present 
 appearances or images, conclusions as to future occur- 
 rences, and, by that prevision, to determine what should 
 or should not be done. 
 
 Note 3, p. 166. And with respect to all which, &c.] 
 This passage seems, although obscure from its brevity, to
 
 CH. VII. NOTES. 313 
 
 imply that without action, when thoughts are not carried 
 out that is, there can for us be neither good nor bad, as 
 these are relations pertaining to individuals, and dependent, 
 not upon any universal law but, upon social institutions ; 
 but that tmth, being the same for ever, is, even when not 
 exercised, in an absolute relation to all men, and in oppo- 
 sition to all falsehood. 
 
 Note 4, p. 166. The mind dwells upon abstractions, 
 &c.] The term abstractions here, as in an earlier passage, 
 signifies mathematical questions, which, from not being 
 referrible to any particular body, admit of being treated as 
 such ; and so a snub- nose, as the realisation of a particular 
 form, may, by that form apart from matter, be regarded 
 as an abstraction. The argument is then resumed that 
 the mind, when thinking, is, wJien active or in act, the 
 subject thought upon. The closing passage, by its ques- 
 tioning whether " the mind, witliout being itself imma- 
 terial, can comprehend abstractions," seems to militate 
 against the arguments adduced to prove that it is impassive 
 and homogeneous, freed, that is, from all the conditions of 
 matter ; but it is yet doubtful where (whether or not in 
 "the metaphysics") this argument may, according to 
 promise, have been continued.
 
 314 NOTES. [BK. m. 
 
 CHAPTER VIII. 
 
 Note 1, p. 169. But tJie question here must necessarily 
 refer, &c.] This argument, while maintaining the opinion 
 that sensibility is receptive of form without matter, is an 
 objection to the doctrine of Empedocles and others, who, 
 having derived the Vital Principle from material elements, 
 made perception to be material also, in the relation of 
 like by like. But here it is said that, as the hand is the 
 instrument for making instruments, so the mind is the 
 archetype of forms, and sensibility the recipient of the 
 forms of things without their matter, perceived through 
 the senses. Aristotle, however, does make imagery, the 
 power that is, of recalling forms, to be essential to cogi- 
 tation, and, consequently, to reflection ; although doubting 
 whether there may not be thoughts which cannot have a 
 sentient origin. 
 
 Note 2, p. 170. Imagination, on the other hand, 
 &c.] Imagination, or the faculty which calls up images 
 is, necessarily, different from that which determines the 
 truth or falsehood of any proposition, and which affirms 
 or denies ; for affirmation or negation, as the predicant 
 of something held to be true or erroneous, is, as was said, 
 a combination of thoughts ; and thoughts, being made up
 
 CH. IX.] NOTES. 315 
 
 of simple ideas, are not, like the imagination, under our 
 own control. Thus, while the former may be regarded as 
 a single faculty, and, in some sense, independent of the 
 judgment, the latter involves many and opposing ideas 
 and perceptions. But what is here meant by primal 
 thoughts (TO. 2e -n-pw-ra vo^aTa)1 Do the words imply 
 innate ideas, or conceptions of pure abstraction, such as 
 creation, virtue, responsibility, and others'? Or must it 
 be admitted that no definite sense can be attached to 
 them 1 If primal mean innate thoughts, (thoughts, that 
 is, no way dependent upon sentient properties,) then such 
 are distinguishable at once from those which are derived 
 from images, although these are not, themselves, images 
 in reality. 
 
 CHAPTER IX. 
 
 Note 1, p. 173. But a difficulty at once presents itself, 
 &c.] There is an apparent want of discrimination here 
 between the faculties which are the privilege and dis- 
 tinction of higher creatures and the functions which are 
 essential to life, and without which there can be neither 
 animal nor living being. In a subsequent paragraph the 
 rational faculty or mind (al o KaXov/jLevus i/oi/s) is ex- 
 cluded from all participation in corporeal movements, 
 and held to have no part in sentient perception. It is
 
 316 NOTES. [BK. in, 
 
 supposed, in fact, never to be engaged upon what is prac- 
 tical as its office is contemplation, so that, " when dwelling 
 upon what may be fearful, or otherwise, it does not, at 
 once, suggest, flight or pursuit ; " although, independently 
 of its influence, "the heart or some other organ of the 
 body maybe accelerated or depressed." But in all this, as 
 no allusion is made to a moving force, whether the 
 motive be imagination or the stimulus of appetite, the 
 inquiry may be said to be defective. 
 
 Note 2, p. 173. But to resume the more especial, &c.] 
 Although these passages, which allude both to physical 
 and moral causes of motion, are sufficiently obvious, yet, as 
 they do not explain how locomotion is effected, they fail 
 in the object of the inquiry ; and then the motion con- 
 cerned in nutrition, growth and decay, is almost in the 
 same category, so to say, with that of progression. It 
 may be mentioned that the " motion and progression of 
 animals," " breathing and expiration," " sleep and watch- 
 ing," "youth and age," are special treatises, and probably 
 composed for the elucidation of this particular work upon 
 " life." The comparison between the intemperate man 
 who, although rational, acts against his reason, and the 
 physician who, although versed in medical science, does 
 not cure, seems to exemplify the adage, that to advise is 
 one thing, to do, another ; or to confirm the solemn words 
 of Johnson, "that teachers of morality discourse like 
 angels, but they live like men."
 
 CH. X.] NOTES. 317 
 
 CHAPTER X. 
 
 Note 1, p. 178. Thus it is the object longed for alone, 
 &c.] Food, that is, being necessary both for stilling the 
 appetite and preserving the body, is the first motor ; for, 
 were there, as the text says, two motors, then, as the 
 practical mind never impels to move without appetite, 
 appetite could not impel to move without the mind, 
 which is not the case. This is the argument ; but it is 
 less distinct than might be wished for owing to the 
 nature of the practical mind not having been defined, 
 and to insufficient knowledge concerning both muscular 
 agency and the brain and nervous system. 
 
 Note 2, p. 178. The mind then is always right, &c.] 
 The intellect, that is, when neither moved by appetite 
 nor perverted by imagination, (for both may be wrong) is, 
 when freed from those influences, always right ; but food 
 incites to move because it is either good or appears to be 
 a good, in the sense, not of a moral but, of a practical 
 good, and, as such, it may, by abuse, be the opposite of 
 good. 
 
 Note 3, p. 179. The, appetites admit of being opposed, 
 &c.] "Appetite and reason are not always in accord- 
 ance," Aristotle 1 observes, and as, when any one desire is 
 1 Eih. End. n. 8. 5.
 
 318 NOTES. [BK. in. 
 
 subdued another may arise and strive for the mastery, so 
 appetite may well be opposed to appetite. But resistance 
 to desire can be manifested only in such beings as have a 
 sense of time, have, that is, powers of abstraction, by 
 which, withdrawing themselves from what is present, and 
 foreseeing consequences in the future, they are enabled to 
 resist the immediate compliance which desire or passion 
 is urging upon them. For "the 1 portion of time now 
 present, is a portion of that which is future and indi- 
 visible." 
 
 Note 4, p. 179. For loithout having been itself -moved, 
 &c.] Owing to the wording there is obscurity about 
 this passage, but yet it may be elucidated the object 
 desired, food, that is, although at rest, may, acting 
 upon the appetitive sense, incite to move, and so be 
 regarded as a motor; and there are, of course, as many 
 such motors as there are kinds of food. These then are 
 the three terms first, the motor or food; then the 
 muscular agency by which locomotion is effected ; and 
 lastly, that which is moved, or the animal. 
 
 Note 5, p. 180. ut to speak summarily, &c.] The 
 passage has, in this version, been rendered with a bias 
 that the analogy was drawn from the structure of the 
 knee-joint, which, in all times, has been likened to a 
 hinge, and hence termed " ginglymoid ; " and concholo- 
 gists, following Aristotle 1 , have so termed the hinge of 
 
 1 Nat. Ausc. rv. ro. 
 
 3 Hist. Animalm, IV. 4. 11.
 
 CH. XI.] NOTES. 319 
 
 the bivalves. The Latin is, " nunc ut in summa dicamus, 
 id quod movet ut instrumentum, ibi est collocandum ubi 
 idem piincipii rationem finisve subit ut in cardine fit 
 hinc enim convexum et concavum est ; quorum alterum 
 finis, alterum principium est ; quapropter alienum quiescit 
 alterum movetur." The closing paragraph seems to con- 
 firm what has been assumed, that sentient imagination is 
 analogous to " animal instinct." 
 
 CHAPTER XL 
 
 Note 1, p. 182. The sentient imagination belongs, 
 &c.] Instinct is the fixed but unerring guide of the 
 lower animals ; the voluntary imagination, on the other 
 hand, the faculty, that is, which can, at will, be called up 
 and supply images for selection and combination by the 
 judgment, can belong only to beings endowed with 
 reason that is, to man. The faculties associated with 
 this imagination, enable the individual, by idealising a 
 measure, to select what may be, relatively, larger and 
 better, and out of several impressions or sensations, to 
 form general notions. It is unnecessary to follow the 
 argument which explains why these creatures, so low 
 in the scale, cannot form opinions. 
 
 Note 2, p. 182. But appetite has no deliberative 
 icill, &c.] The meaning of this passage is, seemingly, too
 
 320 NOTES. [BK. in. 
 
 obvious to require comment ; but some commentators 
 have in the term o-QaTpa seen an allusion to the celestial 
 spheres, rather than a ball, because, as the upper controls 
 in its movements the lower sphere, so reason, being 
 superior to appetite, is to control inordinate desires. 
 " Quibus collatis, non temerarium erit, o-^a/pa? similitu- 
 dinem ita interpretari : consilium tanquam superius 
 (/ ai/co) ita appetitum in suum motum convertere, sicut 
 superior sphsera eas, quce inferiores volvuntur." The 
 words which follow " that which is superior is ever 
 naturally more dominant," may require some such 
 interpretation, for they seem to imply that motion, by 
 translation, may be derived from the motions of the 
 spheres above, which were said to be in three directions ; 
 but the knowing faculty, the mind, that is, like the first 
 motor, is, for ever, at rest. 
 
 Note 3, p. 183. Although tfte conception of tlie uni- 
 versal, &c.] This abstruse passage can only be under- 
 stood by reference to the special treatise upon " the 
 motion of animals, wherein this topic is considered;" it 
 is asked, " whence comes it, that an individual, after 
 thinking, sometimes acts and sometimes does not act, 
 sometimes moves and sometimes does not move?" and 
 the answer 1 is, that "action or motion is the conclusion 
 of a syllogism," of which " the conception of the universal 
 is the major, that of the particular, the middle, and the 
 action following it the minor." 
 
 1 De Motu Animalm, 5. f. i.
 
 CH. XII.] NOTES. 321 
 
 CHAPTER XII. 
 
 Note 1, p. 186. Simple or homogeneous bodies, <fec.] 
 There is no clue in Aristotle's writings to the meaning 
 of "simple (or homogeneous) bodies" (TO o-w/ua aVAoi/i/), 
 unless it be the Acalepha ', " the body of which, like 
 that of the oyster, is said to be altogether fleshy, but, 
 unlike the oyster, to be without a shell ; and it is further 
 said to belong rather to plants than animals." But 
 as in the following chapter it is shewn that an animal 
 body, if homogeneous, cannot exist, so the tenor of the 
 whole argument may be, to shew that no animal body 
 can be homogeneous. 
 
 Note 2, p. 187. As to creatures which are fisced, &c.] 
 These include such species of the Testacea as are fixed 
 to one habitat, and derive nutriment from the water with 
 which they are surrounded ; but it is not easy to deter- 
 mine what is meant by the term dyevinjrov, (spontaneously 
 generated,) as this mode of reproduction was attributed, 
 by Aristotle, to some fishes and eels, which are certainly 
 neither homogeneous nor insentient. 
 
 Note 3, p. 188. The otlter senses, being for, &c.] It may 
 be questioned whether this description is absolutely true, 
 
 1 Hist. Animalm, iv. 6. 6. vui. i. 7. 
 
 21
 
 3'2'2 NOTES. [BK. in. 
 
 as there are creatures which, although fixed to one 
 habitat, not capable of progression that is, are endowed 
 with all the senses, although it may be in some modified, 
 or less active form than in the higher animals. For 
 " the l nervous system has been detected in every division 
 of the animal kingdom, and almost in every class, and it is 
 everywhere connected with sensation and motion." 
 
 Xote -4, p. 188. Be sensible through a medium, etc.] 
 The medium, that is, made diaphanous and motive by 
 colour or sound, acts, by a succession of undulations, 
 upon the eye or the ear, and finally, through the humours 
 of the former and the air in the latter, upon the sentient 
 part of these organs ; so that there is an evident analogy 
 between these undulations and the impulses which main- 
 tain locomotion until lost in the state of rest. This 
 succession of impulses may well apply to the changes 
 which, without change of locality, are slowly and silently 
 going on in bodies, and be compared to colouring matter 
 which permeates and gradually combines with each 
 molecule of wax up to saturation ; but every substance 
 cannot, of course, be thus affected a stone, for instance, 
 owing to the condensation of its particles, cannot be 
 made receptive of colour. 
 
 Note 5, p. 189. The air if mobile in the highest 
 
 degree, <kc.] The nature and properties of the atmosphere 
 
 were imperfectly known, as has been said, in the age of 
 
 Aristotle. It was deemed necessary to sensation that 
 
 1 Grant's Outline*, 179.
 
 CH. XII.] NOTES. 323 
 
 the air should be still (for, when in motion, it was con- 
 verted, according to opinion, into wind), and as one mass ; 
 and as this aggregation of the air could be only over 
 smooth surfaces, the outer coat of the eye (the cornea) 
 seemed, by its smoothness, to favour Aristotle's doctrine, 
 that vision is through a medium, and completed, by 
 refraction, at the bottom of the organ. The medium, set 
 in motion, by colour, was said to give motion, by successive 
 impulses, to the air over the cornea, which communicated 
 the impulse to the organ within ; and this superseded 
 the doctrine that vision is produced by rays emanating 
 from the eya Thus, " the air (that over the cornea), in 
 its turn, sets vision in motion ;" but the last clause of 
 the sentence is very obscure, and offers, as some com- 
 mentators have said, "great difficulties." It may, per- 
 chance, be a continuation of the analogy and suggest 
 that, as colouring matter acts, successively, until each 
 particle is saturated, so the impulse is transmitted to the 
 cornea, and finally, from it, to the visual faculty within.
 
 324 NOTES. [BK. in. 
 
 CHAPTER XIII. 
 
 Note 1, p. 192. The Touch is made sensible... aiid 
 lience its name, &c.] The text refers to etymology to 
 shew, that as, in all times, it had been noticed that the 
 impression upon other senses is different from that upon 
 Touch, it had hence obtained its appellation a$/, which, 
 being derived from OTTTW, (to fasten or bind,) signifies 
 fastening or binding, and so (by touching,) immediate 
 contact ; as contact is necessary for the sensation of 
 Touch. This may suffice for the explanation of the 
 term in the original, but it may not, of course, be 
 applicable to its synonym in a modern language, since its 
 origin may be from another idea, and, therefore, a dif- 
 ferent root. 
 
 Note 2, p. 192. And yet the other sentient organs, <fec.] 
 It had been proved analogically, that, as bodies in the 
 water are separated by the water, (as was supposed to be 
 proved by their extremities being wet,) so bodies in the 
 air are separated by air, and therefore, that, as no one 
 body is in immediate contact with another body, sensa- 
 tion can be effected only through a medium ; and this 
 was supposed to hold good even for the Touch. Thus, 
 the medium, acted upon and acting in its turn, reduces
 
 CH. XIII.J NOTES. 325 
 
 all sensual impressions to the one impression by contact, 
 and this generalisation is supported by some modern 
 writers and regarded as the theory of Sensation. " There * 
 may, however, be many other impressions derived from 
 outward bodies, for which the sensitive nerves of the 
 lower animals are adapted, besides those which affect us, 
 and we cannot always be certain of the identity of the 
 feelings communicated to them by organs which appear 
 analogous to our own." 
 
 Note 3, p. 193. On which account, other sentient, <fec.] 
 This is consonant with the opinion that the Touch is the 
 only sense necessary to animal existence; although the 
 organs of relation are required for the higher forms of 
 being. Thus, impressions in excess upon those organs, 
 whether by colour, sound, or odour, may injure or pervert 
 the senses, but cannot further affect the individual ; 
 while tangible impressions, hot, cold, or hard, can 
 together with the sense destroy the animal. 
 
 Note 4, p. 193. Animals, in fact, possess... the other 
 senses, <fec.] This is referrible, of course, only to the 
 higher orders of animals, as they alone require such 
 organs for the exercise of their faculties, and the enjoy- 
 ment of their existence. The Tongue is here introduced, 
 whether by inadvertence or in submission to common 
 opinion, as if it were a sense, or the sole organ for 
 speech; and yet, as the chief of the organs for taste 
 
 1 Grant's Outlinet, p. 248.
 
 326 NOTES. [BK. in. 
 
 and speech, it may be said to constitute one of the 
 distinguishing features of humanity. As no creature, 
 however, is without a tongue, it can scarcely be supposed 
 to be wanting, and yet, as it would not seem to be so 
 essential as some other parts, life might, perhaps, for a 
 time, be maintained without it. But speech is, of course, 
 nowise necessary to life, as the learned commentator 
 observes: "Nam etiam linguae sermone, si vitam, de- 
 tractis ornamentis, ad necessitatis angustias redigere velis, 
 vitse conservatio carere potest. : '
 
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