ARI STOTLE 
 
 A E TAYLOR, F B A 
 
 
 THE-PEOPLE'S -BOOKS
 
 THE 
 
 PEOPLE'S 
 BOOKS 
 
 ARISTOTLE
 
 ARISTOTLE 
 
 BY A. E. TAYLOR, M.A., D.LITT., F.B.A. 
 
 LONDON: T. C. & E. C. JACK 
 67 LONG ACRE, W.C., AND EDINBURGH 
 NEW YORK. DODGE PUBLISHING CO.
 
 CONTENTS 
 
 CHAP. PAGE 
 
 I. LIFE AND WORKS ...... 7 
 
 II. THE CLASSIFICATION OF THE SCIENCES : SCIENTIFIC 
 
 METHOD . .14 
 
 III. FIRST PHILOSOPHY .35 
 
 IV. PHYSICS .51 
 
 V. PRACTICAL PHILOSOPHY . . . . .72 
 
 BIBLIOGRAPHY > 91
 
 ARISTOTLE 
 
 CHAPTER I 
 
 LIFE AND WORKS 
 
 IT has not commonly been the lot of philosophers, as it is of 
 great poets, that their names should become household words. 
 We should hardly call an Englishman well read if he had not 
 heard the name of Sophocles or Moliere. An educated man is 
 expected to know at least who these great writers were, and 
 to understand an allusion to the Antigone or Le Misanthrope. 
 But we call a man well read if his mind is stored with the 
 verse of poets and the prose of historians, even though he were 
 ignorant of the name of Descartes or Kant. Yet there are a 
 few philosophers whose influence on thought and language has 
 been so extensive that no one who reads can be ignorant of 
 their names, and that every man who speaks the language 
 of educated Europeans is constantly using their vocabulary. 
 Among this few Aristotle holds not the lowest place. We have 
 all heard of him, as we have all heard of Homer. He has left 
 his impress so firmly on theology that many of the formulae of the 
 Churches are unintelligible without acquaintance with his con- 
 ception of the universe. If we are interested in the growth of 
 modern science we shall readily discover for ourselves that some 
 knowledge of Aristotelianisin is necessary for the understanding 
 of Bacon and Galileo and the other great anti-Aristotelians who 
 created the " modern scientific " view of Nature. If we turn to 
 the imaginative literature of the modern languages, Dante is a 
 sealed book, and many a passage of Chaucer and Shakespeare 
 and Milton is half unmeaning to us unless we are. at home 
 in the outlines of Aristotle's philosophy. And if we turn to 
 
 7
 
 8 ARISTOTLE 
 
 ordinary language, we find that many of the familiar turns of 
 modern speech cannot be fully understood without a knowledge 
 of the doctrines they were first forged to express. An English- 
 man who speaks of the " golden mean " or of " liberal educa- 
 tion," or contrasts the " matter" of a work of literature with its 
 " form," or the " essential " features of a situation or a scheme 
 of policy with its " accidents," or " theory " with " practice," 
 is using words which derive their significance from the part 
 they play in the vocabulary of Aristotle. The unambitious 
 object of this little book is, then, to help the English reader to 
 a better understanding of such familiar language and a fuller 
 comprehension of much that he will find in Dante and Shake- 
 speare and Bacon. 
 
 Life of Aristotle. The main facts of Aristotle's life may be 
 briefly told. He was born in 385-4 B.C. at Stagirus, a little 
 city of the Chalcidic peninsula, still called, almost by its 
 ancient name, Chalcis, and died at the age of sixty-two at 
 Chalcis in Euboea. Thus he is a contemporary of Demosthenes, 
 his manhood witnessed the struggle which ended in the estab- 
 lishment of the Macedonian monarchy as the dominant power 
 in Hellas, and his later years the campaigns in which his pupil 
 Alexander the Great overthrew the Persian Empire and carried 
 Greek civilisation to the banks of the Jumna. In studying 
 the constitutional theories of Aristotle, it is necessary to bear 
 these facts in mind. They help to explain certain limitations 
 of outlook which might otherwise appear strange in so great a 
 man. It throws a Jjreat deal of light on the philosopher's in- 
 tense conviction of the natural inferiority of the "barbarian" 
 intellect and character to remember that he grew up in an out- 
 lying region where the " barbarian " was seen to disadvantage 
 in the ordinary course of life. Hence the distinction between 
 Greek and " barbarian " came to mean for him much what the 
 " colour-line " does to an American brought up in a Southern 
 State. So, again, when we are struck by his " provincialism," 
 his apparent satisfaction with the ideal of a small self-contained 
 city-state with a decently oligarchical government, a good 
 system of public education, and no " social problems," but de- 
 void alike of great traditions and far-reaching ambitions, we 
 must remember that the philosopher himself belonged to just 
 such a tiny community without a past and without a future.
 
 LIFE AND WORKS 9 
 
 The Chalcidic cities had been first founded, as the name of the 
 peninsula implies, as colonies from the town of Chalcis in 
 Euboea; Corinth had also been prominent in establishing 
 settlements in the same region. At the height of Athenian 
 Imperial prosperity in the age of Pericles the district had fallen 
 politically under Athenian control, but had been detached again 
 from Athens, in the last years of the Archidamian war, by the 
 genius of the great Spartan soldier and diplomat Brasidas. 
 Early in the fourth century the Chalcidic cities had attempted 
 to form themselves into an independent federation, but the 
 movement had been put down by Sparta, and the cities had 
 fallen under the control of the rising Macedonian monarchy, 
 when Aristotle was a baby. A generation later, a double in- 
 trigue of the cities with Philip of Macedon and Athens failed 
 of its effect, and the peninsula was finally incorporated with 
 the Macedonian kingdom. It is also important to note that 
 the philosopher belonged by birth to a guild, the Asclepiadae, 
 in which the medical profession was hereditary. His father 
 Nicomachus was court physician to Amyntas II., the king for 
 whose benefit the Spartans had put down the Chalcidic league. 
 This early connection with medicine and with the Macedonian 
 court explains largely both the predominantly biological cast of 
 Aristotle's philosophical thought and the intense dislike of 
 " princes " and courts to which he more than once gives expres- 
 sion. At the age of eighteen, in 367-6, Aristotle was sent to 
 Athens for "higher" education in philosophy and science, and 
 entered the famous Platonic Academy, where he remained as a 
 member of the scientific group gathered round the master for 
 twenty years, until Plato's death in 347-6. For the three 
 years immediately following Aristotle was in Asia Minor with 
 his friend and fellow-student Hermeias, who had become by 
 force of sheer capacity monarch of the city of Atarneus in the 
 Troad, and was maintaining himself with much energy against 
 the Persian king. Pythias, the niece of Hermeias, became the 
 philosopher's wife, and it seems that the marriage was happy. 
 Examination of Aristotle's contributions to marine biology has 
 shown that his knowledge of the subject is specially good for 
 the Aeolic coast and the shores of the adjacent islands. This 
 throws light on his occupations during his residence with 
 Hermeias, and suggests that Plato had discerned the bent of
 
 10 ARISTOTLE 
 
 his distinguished pupil's mind, and that his special share in 
 the researches of the Academy had, like that of Speusippus, 
 Plato's nephew and successor in the headship of the school, been 
 largely of a biological kind. We also know that, presumably 
 shortly after Plato's death, Aristotle had been one of the group 
 of disciples who edited their teacher's unpublished lectures. 
 In 343 Hermeias was assassinated at the instigation of Persia ; 
 Aristotle honoured his memory by a hymn setting forth the 
 godlikeness of virtue as illustrated by the life of his friend. 
 Aristotle now removed to the Macedonian court, where he re- 
 ceived the position of tutor to the Crown Prince, afterwards 
 Alexander the Great, at this time (343 B.C.) a boy of thirteen. 
 The association of the great philosopher and the great king as 
 tutor and pupil has naturally struck the imagination of later 
 ages ; even in Plutarch's Life of Alexander we meet already 
 with the full-blown legend of the influence of Aristotle's philoso- 
 phical speculations on Alexander. It is, however, improbable 
 that Aristotle's influence counted for much in forming the 
 character of Alexander. Aristotle's dislike of monarchies and 
 their accessories is written large on many a page of his Ethics 
 and Politics; the small self-contained city-state with no political 
 ambitions for which he reserves his admiration would have 
 seemed a mere relic of antiquity to Philip and Alexander. The 
 only piece of contemporary evidence as to the relations between 
 tne master and the pupil is a sentence in a letter to the young 
 Alexander from the Athenian publicist Isocrates who malici- 
 ously congratulates the prince on his preference for " rhetoric," 
 the art of efficient public speech, and his indifference to " logic- 
 choppers." How little sympathy Aristotle can have had with his 
 pupil's ambitions is shown by the fact that though his political 
 theories must have been worked out during the very years in 
 which Alexander was revolutionising Hellenism by the founda- 
 tion of his world-empire, they contain no allusion to so momen- 
 tous a change in the social order. For all that Aristotle tells 
 us, Alexander might never have existed, and the small city- 
 state might have been the last word of Hellenic political de- 
 velopment. Hence it is probable that the selection of Aristotle, 
 who had not yet appeared before the world as an independent 
 thinker, to take part in the education of the Crown Prince was 
 due less to personal reputation than to the connection of his
 
 LIFE AND WORKS 11 
 
 family with the court, taken together with his own position as 
 a pupil of Plato, whose intervention in the public affairs of 
 Sicily had caused the Academy to be regarded as the special 
 home of scientific interest in politics and jurisprudence. It 
 may be true that Alexander found time in the midst of his 
 conquests to supply his old tutor with zoological specimens ; 
 it is as certain as such a thing can be that the ideals and 
 characters of the two men were too different to allow of any 
 intimate influence of either on the other. 
 
 When Alexander was suddenly called to the Macedonian 
 throne by the murder of his father in 336 B.C., Aristotle's 
 services were no longer needed ; he returned to Athens and 
 gave himself to purely scientific work. Just at this juncture 
 the presidency of the Academy was vacant by the death of 
 Speusippus, Aristotle's old associate in biological research. 
 Possibly Aristotle thought himself injured when the school 
 passed him over and elected Xenocrates of Chalcedon as its new 
 president. At any rate, though he appears never to have 
 wholly severed his connection with the Academy, in 335 he 
 opened a rival institution in the Lyceum, or gymnasium attached 
 to the temple of Apollo Lyceus, to which he was followed by 
 some of the most distinguished members of the Academy. From 
 the fact that his instruction was given in the peripatos or 
 covered portico of the gymnasium the school has derived its 
 name of Peripatetic. For the next twelve years he was occupied 
 in the organisation of the school as an abode for the prosecution 
 of speculation and research in every department of inquiry, and 
 in the composition of numerous courses of lectures on scientific 
 and philosophical questions. The chief difference in general 
 character between the new school and the Academy is that 
 while the scientific interests of the Platonists centred in mathe- 
 matics, the main contributions of the Lyceum to science lay in 
 the departments of biology and history. 
 
 Towards the end of Alexander's life his attention was un- 
 favourably directed on his old teacher. A relative of Aristotle 
 named Callisthenes had attended Alexander in his campaigns as 
 historiographer, and had provoked disfavour by his censure of 
 the King's attempts to invest his semi-constitutional position 
 towards his Hellenic subjects with the pomp of an Oriental 
 despotism. The historian's independence proved fatal. He
 
 12 ARISTOTLE 
 
 was accused of instigating an assassination plot among 
 Alexander's pages, and hanged, or, as some said, thrown into a 
 prison where he died before trial. Alexander is reported to 
 have held Aristotle responsible for his relative's treason, and to 
 have meditated revenge. If this is so, he was fortunately 
 diverted from the commission of a crime by preoccupation with 
 , the invasion of India. 
 
 On the death of Alexander in 323 a brief but vigorous anti- 
 Macedonian agitation broke out at Athens. Aristotle, from his 
 Macedonian connections, naturally fell a victim, in spite of his 
 want of sympathy with the ideals of Philip and Alexander. 
 Like Socrates, he was indicted on the capital charge of "impiety," 
 the pretext being that his poem on the death of Hermeias, 
 written twenty years before, was a virtual deification of his 
 friend. This was, however, only a pretext; the real offence 
 was political, and lay in his connection with the Macedonian 
 leader Antipater. As condemnation was certain, the philosopher 
 anticipated it by withdrawing with his disciples to Chalcis, the 
 mother city of his native Stagirus. Here he died in the follow- 
 ing year, at the age of sixty-two or sixty-three. 
 
 The features of Aristotle, familiar to us from busts and 
 intaglios, are handsome, but indicate refinement and acuteness 
 rather than originality, an impression in keeping with what we 
 should expect from a study of his writings. The anecdotes 
 related of him reveal a kindly, affectionate character, and show 
 little trace of the self-importance which appears in his work. 
 His will, which has been preserved, exhibits the same traits in 
 its references to his happy family life and its solicitous care for 
 the future of his children and servants. He was twice married, 
 first to Pythias, and secondly to a certain Herpyllis, by whom 
 he left a son Nicomachus and a daughter. The " goodness " of 
 Herpyllis to her husband is specially mentioned in the clauses 
 of the will which make provision for her, while the warmth of 
 the writer's feelings for Pythias is shown by the direction that 
 her remains are to be placed in the same tomb with his own. 
 The list of servants remembered and the bequests enumerated 
 show the philosopher to have been in easier circumstances than 
 Plato. 
 
 The Works of Aristotle. The so-called works of Aristotle 
 present us with a curious problem. When we turn from Plato
 
 LIFE AND WORKS 13 
 
 to his pupil we seem to have passed into a different atmos- 
 phere. The Discourses of Socrates exhibit a prose style 
 which is perhaps the most marvellous of all literary achieve- 
 ments. Nowhere else do we meet with quite the same combi- 
 nation of eloquence, imaginative splendour, incisive logic, and 
 irresistible wit and humour. The manner of Aristotle is dry 
 and formal. His language bristles with technicalities, makes 
 little appeal to the emotions, disdains graces of style, and 
 frequently defies the simplest rules of composition. Our sur- 
 prise is all the greater that we find later writers of antiquity, 
 such as Cicero, commending Aristotle for his copious and golden 
 eloquence, a characteristic which is conspicuously wanting in 
 the Aristotelian writings we possess. The explanation of the 
 puzzle is, however, simple. Plato and Aristotle were at once 
 what we should call professors and men of letters ; both wrote 
 works for general circulation, and both delivered courses of 
 lectures to special students. But while Plato's lectures have 
 perished, his books have come down to us. Aristotle's books 
 have almost wholly been lost, but we possess many of his lectures. 
 The " works " of Aristotle praised by Cicero for their eloquence 
 were philosophical dialogues, and formed the model for Cicero's 
 own compositions in this kind. None of them have survived, 
 though some passages have been preserved in quotations by 
 later writers. That the " works " are actually the MSS. of a 
 lecturer posthumously edited by his pupils seems clear from 
 external as well as from internal evidence. In one instance we 
 have the advantage of a double recension. Aristotle's Ethics 
 or Discourses on Conduct have come down to us in two 
 forms the so-called Nicomaehean Ethics, a redaction by the 
 philosopher's son, Nicomachus, preserving all the characteristics 
 of an oral course of lectures ; and a freer and more readable recast 
 by a pupil, the mathematician Eudemus, known as the Eudemian 
 Ethics. In recent years we have also recovered from the sands 
 of Egypt what appears to be our one specimen of a " work " of 
 Aristotle, intended to be read by the public at large, the essay 
 on the Constitution of Athens. The style of this essay is easy, 
 flowing, and popular, and shows that Aristotle could write well 
 and gracefully when he thought fit.
 
 14 ARISTOTLE 
 
 CHAPTER II 
 
 THE CLASSIFICATION OF THE SCIENCES ! SCIENTIFIC METHOD 
 
 PHILOSOPHY, as understood by Aristotle, may be said to be 
 the organised whole of disinterested knowledge, that is, know- 
 ledge which we seek for the satisfaction which it carries with 
 itself, and not as a mere means to utilitarian ends. The impulse 
 which receives this satisfaction is curiosity or wonder, which 
 Aristotle regards as innate in man, though it does not get full 
 play until civilisation has advanced far enough to make secure 
 provision for the immediate material needs of life. Human 
 curiosity was naturally directed first to the outstanding 
 "marvellous works" of the physical world, the planets, the 
 periodicity of their movements, the return of the seasons, 
 winds, thunder and lightning, and the like. Hence the earliest 
 Greek speculation was concerned with problems of astronomy 
 and meteorology. Then, as reflection developed, men speculated 
 about geometrical figure, and number, the possibility of hav- 
 ing assured knowledge at all, the character of the common 
 principles assumed in all branches of study or of the special 
 principles assumed in some one branch, and thus philosophy 
 has finally become the disinterested study of every department 
 of Being or Reality. Since Aristotle, like Hegel, thought that 
 his own doctrine was, in essentials, the last word of specula- 
 tion, the complete expression of the principles by which his 
 predecessors had been unconsciously guided, he believes himself 
 in a position to make a final classification of the branches of 
 science, showing how they are related and how they are dis- 
 criminated from one another. This classification we have now 
 to consider. 
 
 Classification of the Sciences. To begin with, we have to 
 discriminate Philosophy from two rivals with which it might 
 be confounded on a superficial view, Dialectic and Sophistry. 
 Dialectic is the art of reasoning accurately from given premisses, 
 true or false. This art has its proper uses, and of one of these 
 we shall have to speak. But in itself it is indifferent to the 
 truth of its premisses. You may reason dialectically from pre-
 
 CLASSIFICATION OF THE SCIENCES 15 
 
 misses which you believe to be false, for the express purpose of 
 showing the absurd conclusions to which they lead. Or you 
 may reason from premisses which you assume tentatively to see 
 what conclusions you are committed to if you adopt them. In 
 either case your object is not directly to secure truth, but 
 only to secure consistency. Science or Philosophy aims directly 
 at truth, and hence requires to start with true and certain 
 premisses. Thus the distinction between Science and Dialectic 
 is that Science reasons from true premisses, Dialectic only from 
 " probable " or " plausible " premisses. Sophistry differs from 
 Science in virtue of its moral character. It is the profession 
 of making a living by the abuse of reasoning, the trick of 
 employing logical skill for the apparent demonstration o 
 scientific or ethical falsehoods. "The sophist is one who 
 earns a living from an apparent but unreal wisdom." (The 
 emphasis thus falls on the notion of making an " unreal 
 wisdom " into a trade. The sophist's real concern is to get 
 his fee.) Science or Philosophy is thus the disinterested 
 employment of the understanding in the discovery of truth. 
 
 We may now distinguish the different branches of science as 
 defined. The first and most important division to be made is 
 that between Speculative or Theoretical Science and Practical 
 Science. The broad distinction is that which we should now 
 draw between the Sciences and the Arts (i.e. the industrial 
 and technical, not the " fine " arts). Speculative or Theoretical 
 Philosophy differs from Practical Philosophy in its purpose, and, 
 in consequence, in its subject-matter, and its formal logical 
 character. The purpose of the former is the disinterested con- 
 templation of truths which are what they are independently 
 of our own volition ; its end is to Tcnoiv and only to know. 
 The object of " practical " Science is to know, but not only to 
 know but also to turn our knowledge to account in devising 
 ways of successful interference with the course of events. (The 
 real importance of the distinction comes out in Aristotle's treat- 
 ment of the problems of moral and social science. Since we 
 require knowledge of the moral and social nature of men not 
 merely to satisfy an intellectual interest, but as a basis for a 
 sound system of education and government, Politics, the theory 
 of government, and Ethics, the theory of goodness of conduct, 
 which for Aristotle is only a subordinate branch of Politics, 
 
 B
 
 16 ARISTOTLE 
 
 belong to Practical, not to Theoretical Philosophy, a view 
 which is attended by important consequences.) 
 
 It follows that there is a corresponding difference in the objects 
 investigated by the two branches of Philosophy. Speculative or 
 Theoretical Philosophy is concerned with " that which cannot 
 possibly be other than it is," truths and relations independent 
 of human volition for their subsistence, and calling simply for 
 recognition on our part. Practical Philosophy has to do with 
 relations which human volition can modify, " things which 
 may be other than they are," the contingent. (Thus e.g. 
 not only politics, but medicine and economics will belong to 
 Practical Science.) 
 
 Hence again arises a logical difference between the conclu- 
 sions of Theoretical and those of Practical Philosophy. Those 
 of the former are universal truths deducible with logical 
 necessity from self-evident 1 principles. Those of the latter, 
 because they relate to what " can be otherwise," are never 
 rigidly universal ; they are general rules which hold good " in 
 the majority of cases," but are liable to occasional exceptions 
 owing to the contingent character of the facts with which they 
 deal. It is a proof of a philosopher's lack of grounding in 
 logic that he looks to the results of a practical science (e.g. to 
 the detailed precepts of medicine or ethics) for a higher degree 
 of certainty and validity than the nature of the subject-matter 
 allows. Thus for Aristotle the distinction between the neces- 
 sary and the contingent is real and not merely apparent, and 
 " probability is the guide " in studies which have to do with 
 the direction of life. 
 
 We proceed to the question how many subdivisions there 
 are within "theoretical'' Philosophy itself. Plato had held 
 that there are none. All the sciences are deductions from a 
 single set of ultimate principles which it is the business of 
 that supreme science to which Plato had given the name of 
 Dialectic to establish. This is not Aristotle's view. Accord- 
 ing to him, " theoretical " Philosophy falls into a number of 
 
 1 Self-evident, that is, in a purely logical sense. When you apprehend 
 the principles in question, you see at once that they are true, and do not 
 require to have them proved. It is not meant that any and every man 
 does, in point of fact, always apprehend the principles, or that they can 
 be apprehended -without preliminary mental discipline.
 
 CLASSIFICATION OF THE SCIENCES 17 
 
 distinct though not co-ordinate branches, each with its own 
 special subjects of investigation and its own special axiomatic 
 principles. Of these branches there are three, First Philosophy, 
 Mathematics, and Physics. First Philosophy afterwards 
 to be known to the Middle Ages as Metaphysics 1 treats, to 
 use Aristotle's own expression, of " Being qua Being." This 
 means that it is concerned with the universal characteristics 
 which belong to the system of knowable reality as such, and 
 the principles of its organisation in their full universality. 
 First Philosophy alone investigates the character of those 
 causative factors in the system which are without body or 
 shape and exempt from all mutability. Since in Aristotle's 
 system God is the supreme Cause of this kind, First Philosophy 
 culminates in the knowledge of God, and is hence frequently 
 called Theology. It thus includes an element which would 
 to-day be assigned to the theory of knowledge, as well as one 
 which we should ascribe to metaphysics, since it deals at once 
 with the ultimate postulates of knowledge and the ultimate 
 causes of the order of real existence. 
 
 Mathematics is of narrower scope. What it studies is no 
 longer " real being as such," but only real being in so far as it 
 exhibits number and geometrical form. Since Aristotle holds 
 the view that number and figure only exist as determinations 
 of objects given in perception (though by a convenient fiction 
 the mathematician treats of them in abstraction from the per- 
 ceived objects which they qualify), he marks the difference 
 between Mathematics and First Philosophy by saying that 
 "whereas the objects of First Philosophy are separate from 
 matter and devoid of motion, those of Mathematics, though 
 incapable of motion, have no separable existence but are 
 inherent in matter." Physics is concerned with the study of 
 objects which are both material and capable of motion. Thus 
 the principle of the distinction is the presence or absence of 
 initial restrictions of the range of the different branches of 
 Science. First Philosophy has the widest range, since its 
 
 * The origin of this name seems to be that Aristotle's lectures on First 
 Philosophy came to be studied as a continuation of his course on Physics. 
 Hence the lectures got the name Metaphysica because they came after 
 (meta) those on Physics. Finally the name was transferred (as in the 
 case of Ethics) from the lectures to the subject of which they treat
 
 18 ARISTOTLE 
 
 contemplation covers the whole ground of the real and know- 
 able; Physics the narrowest, because it is confined to a "universe 
 of discourse " restricted by the double qualification that its 
 members are all material and capable of displacement. Mathe- 
 matics holds an intermediate position, since in it, one of these 
 qualifications is removed, but the other still remains, for 
 the geometer's figures are boundaries and limits of sensible 
 bodies, and the arithmetician's numbers properties of collections 
 of concrete objects. It follows also that the initial axioms or 
 postulates of Mathematics form a less simple system than those 
 of First Philosophy, and those of Physics than those of Mathe- 
 matics. Mathematics requires as initial assumptions not only 
 those which hold good for all thought, but certain other special 
 axioms which are only valid and significant for the realm of 
 figure and number ; Physics requires yet further axioms which 
 are only applicable to "what is in motion." This is why, 
 though the three disciplines are treated as distinct, they are 
 not strictly co-ordinate, and "First Philosophy," though 
 " first," is only prima inter pares. 
 
 We thus get the following diagrammatic scheme of the 
 classification of sciences : 
 
 Science 
 
 Theoretical Practical 
 
 First Philosophy Mathe- Physics 
 
 or matics 
 
 Theology 
 
 Practical Philosophy is not subjected by Aristotle to any 
 similar subdivision. Later students were accustomed to recog- 
 nise a threefold division into Ethics (the theory of individual 
 conduct), Economics (the theory of the management of the 
 household), Politics (the theory of the management of the 
 State). Aristotle himself does not make these distinctions. 
 His general name for the theory of conduct is Politics, the 
 doctrine of individual conduct being for him inseparable from 
 that of the right ordering of society. Though he composed a 
 separate course of lectures on individual conduct (the Ethics),
 
 CLASSIFICATION OF THE SCIENCES 19 
 
 he takes care to open the course by stating that the science of 
 which it treats is Politics, and offers an apology for dealing 
 with the education of individual character apart from the more 
 general doctrine of the organisation of society. No special 
 recognition is given in Aristotle's own classification to the 
 Philosophy of Art. Modern students of Aristotle have tried 
 to fill in the omission by adding artistic creation to contem- 
 plation and practice as a third fundamental form of mental 
 activity, and thus making a threefold division of Philosophy 
 into Theoretical, Practical, and Productive. The object of this 
 is to find a place in the classification for Aristotle's famous 
 Poetics and his work on Rhetoric, the art of effective speech 
 and writing. But the admission of the third division of 
 Science has no warrant in the text of Aristotle, nor are the 
 Rhetoric and Poetics, properly speaking, a contribution to 
 Philosophy. They are intended as collections of practical rules 
 for the composition of a pamphlet or a tragedy, not as a critical 
 examination of the canons of literary taste. This was correctly 
 seen by the dramatic theorists of the seventeenth century. They 
 exaggerated the value of Aristotle's directions and entirely mis- 
 understood the meaning of some of them, but they were right 
 in their view that the Poetics was meant to be a collection 
 of rules by obeying which the craftsman might make sure 
 of turning out a successful play. So far as Aristotle has a 
 Philosophy of Fine Art at all, it forms part of his more general 
 theory of education and must be looked for in the general 
 discussion of the aims of education contained in his Politics. 
 
 Tlie Methods of Science. No place has been assigned in 
 the scheme to what we call logic and Aristotle called Analytics, 
 the theory of scientific method, or of proof and the estimation 
 of evidence. The reason is that since the fundamental char- 
 acter of proof is the same in all science, Aristotle looks upon 
 logic as a study of the methods common to all science. At a 
 later date it became a hotly debated question whether logic 
 should be regarded in this way as a study of the methods 
 instrumental to proof in all sciences, or as itself a special 
 constituent division of philosophy. The Aristotelian view was 
 concisely indicated by the name which became attached to the 
 collection of Aristotle's logical works. They were called the 
 Organon, that is, the "instrument," or the body of rules of
 
 20 ARISTOTLE 
 
 method employed by Science. The thought implied is thus 
 that logic furnishes the tools with which every science has to 
 work in establishing its results. Our space will only permit of 
 a brief statement as to the points in which the Aristotelian 
 formal logic appears to be really original, and the main peculi- 
 arities of Aristotle's theory of knowledge. 
 
 (a) Formal Logic. In compass the Aristotelian logic corre- 
 sponds roughly with the contents of modern elementary treatises 
 on the same subject, with the omission of the sections which 
 deal with the so-called Conditional Syllogism. The inclusion 
 of arguments of this type in mediaeval and modern expositions 
 of formal logic is principally due to the Stoics, who preferred to 
 throw their reasoning into these forms and subjected them to 
 minute scrutiny. In his treatment of the doctrine of Terms, 
 Aristotle avoids the mistake of treating the isolated name as 
 though it had significance apart from the enunciations in which 
 it occurs. He is quite clear on the all-important point that 
 the unit of thought is the proposition in which something is 
 affirmed or denied, the one thought-form which can be properly 
 called " true " or " false." Such an assertion he analyses into 
 two factors, that about which something is affirmed or denied (the 
 Subject), and that which is affirmed or denied of it (the Predi- 
 cate). Consequently his doctrine of the classification of Terms is 
 based on a classification of Predicates, or of Propositions accord- 
 ing to the special kind of connection between the Subject and 
 Predicate which they affirm or deny. Two such classifications, 
 which cannot be made to fit into one another, meet us in Aris- 
 totle's logical writings, the scheme of the ten " Categories," and 
 that which was afterwards known in the Middle Ages as the list 
 of " Predicaments " or " Heads of Predicables," or again as the 
 "Five Words." The list of "Categories" reveals itself as an 
 attempt to answer the question in how many different senses the 
 words "is a " or " are " are employed when we assert that " x is 
 y " or " x is a y " or " xs are ya." Such a statement may tell us 
 (1) what x is, as if I say " x is a lion " ; the predicate is then 
 said to fall under the category of Substance; (2) what x is 
 like, as when I say "x is white, or x is wise," the category 
 of Quality ; (3) how much or how many x is, as when I say 
 " x is tall " or " x is five feet long," the category of Quantity ; 
 (4) how x is related to something else, as when I say " x is to
 
 CLASSIFICATION OF THE SCIENCES 21 
 
 the right of y," "x is the father of y" the category of 
 Relation. These are the four chief " categories " discussed by 
 Aristotle. The remainder are (5) Place, (6) Time, (7) and 
 (8) Condition or State, as when I say " x is sitting down " or 
 " x has his armour on," (the only distinction between the two 
 cases seems to be that (7) denotes a more permanent state of x 
 than (8)) ; (9) Action or Activity, as when I say " x is cutting," 
 or generally "x is doing something to y' } ; (10) Passivity, as 
 when I say " x is being cut," op more generally, "so-and-so 
 is being done to x." No attempt is made to show that this 
 list of " figures of predication " is complete, or to point out any 
 principle which has been followed in its construction. It also 
 happens that much the same enumeration is incidentally made 
 in one or two passages of Plato. Hence it is not unlikely 
 that the list was taken over by Aristotle as one which would be 
 familiar to pupils who had read their Plato, and therefore 
 convenient for practical purposes. The fivefold classification 
 does depend on a principle pointed out by Aristotle which 
 guarantees its completeness, and is therefore likely to have 
 been thought out by him for himself, and to be the genuine 
 Aristotelian scheme. Consider an ordinary universal affirm- 
 ative proposition of the form "all XB are ys." Now if this 
 statement is true it may also be true that "all ys are xs," or 
 it may not. On the first supposition we have two possible 
 cases, (1) the predicate may state precisely what the subject 
 defined is; then y is the Definition of ar, as when I say that " men 
 are mortal animals, capable of discourse." Here it is also true 
 to say that "mortal animals capable of discourse are men," 
 and Aristotle regards the predicate " mortal animal capable of 
 discourse " as expressing the inmost nature of man. (2) The 
 predicate may not express the inmost nature of the subject, 
 and yet may belong only to the class denoted by the subject 
 and to every member of that class. The predicate is then 
 called a Proprium or property, an exclusive attribute of the 
 class in question. Thus it was held that "all men are capable 
 of Laughter " and " all beings capable of laughter are men," but 
 that the capacity for laughter is no part of the inmost nature 
 or " real essence " of humanity. It is therefore reckoned as a 
 Proprium. 
 
 Again in the case where it is true that " all xs are ys," but
 
 22 ARISTOTLE 
 
 not true that all "y$ are xs," y may be part of the definition 
 of x or it may not. If it is part of the definition of x it will 
 be either (3) a genus or wider class of which x forms a sub- 
 division, as when I say, " All men are animals," or (4) a dif- 
 ference, that is, one of the distinctive marks by which the xs 
 are distinguished from other sub-classes or species of the same 
 genus, as when I say, " All men are capable of discourse." Or 
 finally (5) y may be no part of the definition of x, but a 
 characteristic which belongs both to the xs and some things 
 other than xs. The predicate is then called an Accident. We 
 have now exhausted all the possible cases, and may say that 
 the predicate of a universal affirmative proposition is always 
 either a definition, a proprium, a genus, a difference, or an ac- 
 cident. This classification reached the Middle Ages not in the 
 precise form in which it is given by Aristotle, but with modifi- 
 cations mainly due to the Neo-Platonic philosopher Porphyry. 
 In its modified form it is regarded as a classification 'of terms 
 generally. Definition disappears from the list, as the definition 
 is regarded as a complex made up of the genus, or next highest 
 class to which the class to be defined belongs, and the differences 
 which mark off this particular species or sub-class. The species 
 itself which figures as the subject-term in a definition is added, 
 and thus the " Five Words " of mediaeval logic are enumei'ated 
 as genus, species, difference, proprium, accident. 
 
 The one point of philosophical interest about this doctrine 
 appears alike in the scheme of the " Categories " in the presence 
 of a category of " substance," and in the list of " Predica- 
 ments " in the sharp distinction drawn between " definition " and 
 " proprium." From a logical point of view it does not appear 
 why any proprium, any character belonging to all the members 
 of a class and to them alone, should not be taken as defining 
 the class. Why should it be assumed that there is only one 
 predicate, viz. 'man, which precisely answers the question, 
 " What is Socrates 1 " Why should it not be equally correct 
 to answer, " a Greek," or " a philosopher " ? The explanation 
 is that Aristotle takes it for granted that not all the distinctions 
 we can make between " kinds " of things are arbitrary and 
 subjective. Nature herself has made certain hard and fast 
 divisions between kinds which it is the business of our thought 
 to recognise and follow. Thus according to Aristotle there is
 
 CLASSIFICATION OF THE SCIENCES 23 
 
 a real gulf, a genuine difference in kind, between the horse and 
 the ass, and this is illustrated by the fact that the mule, the 
 offspring of a horse and an ass, is not capable of reproduction. 
 It is thus a sort of imperfect being, a kind of " monster " 
 existing contra naturam. Such differences as we find when 
 we compare e.g. Egyptians with Greeks do not amount to a 
 difference in " kind." To say that Socrates is a man tells me 
 what Socrates is, because the statement places Socrates in the 
 real kind to which he actually belongs ; to say that he is wise, 
 or old, or a philosopher merely tells me some of his attributes. 
 It follows from this belief in " real " or " natural " kinds that 
 the problem of definition acquires an enormous importance for 
 science. We, who are accustomed to regard the whole business 
 of classification as a matter of making a grouping of our 
 materials such as is most pertinent to the special question we 
 have in hand, tend to look upon any predicate which belongs 
 universally and exclusively to the members of a group, as a 
 sufficient basis for a possible definition of the group. Hence 
 we are prone to take the "nominalist" view of definition, i.e. 
 to look upon a definition as no more than a declaration of the 
 sense which we intend henceforward to put on a word or other 
 symbol. And consequently we readily admit that there may 
 be as many definitions of a class as it has different propria. 
 But in a philosophy like that of Aristotle, in which it is held 
 that a true classification must not only be formally satisfactory, 
 but must also conform to the actual lines of cleavage which 
 Nature has established between kind and kind, the task of 
 classificatory science becomes much more difficult. Science 
 is called on to supply not merely a definition but the definition 
 of the classes it considers, the definition which faithfully reflects 
 the " lines of cleavage " in Nature. This is why the Aristotelian 
 view is that a true definition should always be per genus et 
 differentias. It should "place" a given class by mentioning 
 the wider class next above it in the objective hierarchy, and 
 then enumerating the most deep-seated distinctions by which 
 Nature herself marks off this class from others belonging to 
 the same wider class. Modern evolutionary thought may 
 possibly bring us back to this Aristotelian standpoint. Modern 
 evolutionary science differs from Aristotelian ism on one point 
 of the first importance. It regards the difference between
 
 24 ARISTOTLE 
 
 kinds, not as a primary fact of Nature, but as produced by a 
 long process of accumulation of slight differences. But a 
 world in which the process has progressed far enough will 
 exhibit much the same character as the Nature of Aristotle. 
 As the intermediate links between " species " drop out because 
 they are less thoroughly adapted to maintain themselves than 
 the extremes between which they form links, the world produced 
 approximates more and more to a system of species between 
 which there are unbridgeable chasms ; evolution tends more and 
 more to the final establishment of " real kinds," marked by 
 the fact that there is no permanent possibility of cross-breed- 
 ing between them. This makes it once more possible to dis- 
 tinguish between a " nominal " definition and a " real " defini- 
 tion. From an evolutionary point of view, a " real " definition 
 would be one which specifies not merely enough characters 
 to mark off the group defined from others, but selects also 
 for the purpose those characters which indicate the line of 
 historical development by which the group has successively 
 separated itself from other groups descended from the same 
 ancestors. We shall learn yet more of the significance of this 
 conception of a " real kind " as we go on to make acquaintance 
 with the outlines of First Philosophy. Over the rest of the 
 formal logic of Aristotle we must be content to pass more 
 rapidly. In connection with the doctrine of Propositions, 
 Aristotle lays down the familiar distinction between the four 
 types of proposition according to their quantity (as universal 
 or particular) and quality (as affirmative or negative), and 
 treats of their contrary and contradictory opposition in a way 
 which still forms the basis of the handling of the subject in 
 elementary works on formal logic. He also considers at 
 great length a subject nowadays commonly excluded from the 
 elementary books, the modal distinction between the Problem- 
 atic proposition (x may be ?/), the Assertory (x is y), and the 
 Necessary (x must be y\ and the way in which all these forms 
 may be contradicted. For him, modality is a formal distinc- 
 tion like quantity or quality, because he believes that con- 
 tingency and necessity are not merely relative to the state 
 of our knowledge, but represent real and objective features of 
 the order of Nature. 
 
 In connection with the doctrine of Inference, it is worth
 
 CLASSIFICATION OF THE SCIENCES 26 
 
 while to give his definition of Syllogism or Inference (literally 
 " computation ") in his own words. " Syllogism is a discourse 
 wherein certain things (viz. the premisses) being admitted, 
 something else, different from what has been admitted, follows 
 of necessity because the admissions are what they are." The 
 last clause shows that Aristotle is aware that the all-important 
 thing in an inference is not that the conclusion should be novel 
 but that it should be proved. We may have known the con- 
 clusion as a fact before ; what the inference does for us is to 
 connect it with the rest of our knowledge, and thus to show 
 why it is true. He also formulates the axiom upon which 
 syllogistic inference rests, that " if A is predicated universally 
 of B and B of C, A is necessarily predicated universally of C." 
 Stated in the language of class-inclusion, and adapted to in- 
 clude the case where B is denied of C this becomes the formula, 
 " whatever is asserted universally, whether positively or nega- 
 tively, of a class B is asserted in like manner of any class C 
 which is wholly contained in B," the axiom de omni et nullo 
 of mediaeval logic. The syllogism of the "first figure," to 
 which this principle immediately applies, is accordingly re- 
 garded by Aristotle as the natural and perfect form of infer- 
 ence. Syllogisms of the second and third figures can only 
 be shown to fall under the dictum by a process of " reduction " 
 or transformation into corresponding arguments in the first 
 " figure," and are therefore called " imperfect " or " incomplete," 
 because they do not exhibit the conclusive force of the reason- 
 ing with equal clearness, and also because no universal affirm- 
 ative conclusion can be proved in them, and the aim of science 
 is always to establish such affirmatives. The list of " moods " 
 of the three figures, and the doctrine of the methods by which 
 each mood of the imperfect figures can be replaced by an equi- 
 valent mood of the first is worked out substantially as in our 
 current text-books. The so-called " fourth " figure is not recog- 
 nised, its moods being regarded merely as unnatural and 
 distorted statements of those of the first figure. 
 
 Induction. Of the use of " induction " in Aristotle's philo- 
 sophy we shall speak under the head of " Theory of Know- 
 ledge." Formally it is called " the way of proceeding from 
 particular facts to universals," and Aristotle insists that the 
 conclusion is only proved if all the particulars have been ex-
 
 96 ARISTOTLE 
 
 amined. Thus he gives as an example the following argument, 
 " x, y, z are long-lived species of animals ; x, y, z are the only 
 species which have no gall ; ergo all animals which have no 
 gall are long-lived." This is the " induction by simple enumer- 
 ation " denounced by Francis Bacon on the ground that it 
 may always be discredited by the production of a single " con- 
 trary instance," e.g. a single instance of an animal which has 
 no gall and yet is not long-lived. Aristotle is quite aware 
 that his " induction " does not establish its conclusion unless 
 all the cases have been included in the examination. In fact, 
 as his own example shows, an induction which gives certainty 
 does not start with " particular facts " at all. It is a method 
 of arguing that what has been proved true of each sub-class 
 of a wider class will be true of the wider class as a whole. 
 The premisses are strictly universal throughout. In general, 
 Aristotle does not regard " induction " as proof at all. His- 
 torically " induction " is held by Aristotle to have been first 
 made prominent in philosophy by Socrates, who constantly 
 employed the method in his attempts to establish universal 
 results in moral science. Thus he gives, as a characteristic 
 argument for the famous Socratic doctrine that knowledge 
 is the one thing needful, the " induction," " he who understands 
 the theory of navigation is the best navigator, he who under- 
 stands the theory of chariot-driving the best driver ; from 
 these examples we see that universally he who understands 
 the theory of a thing is the best practitioner," where it is 
 evident that all the relevant cases have not been examined, 
 and consequently that the reasoning does not amount to proof. 
 Mill's so-called reasoning from particulars to particulars finds 
 a place in Aristotle's theory under the name of " arguing from 
 an example." He gives as an illustration, " A war between 
 Athens and Thebes will be a bad thing, for we see that the 
 war between Thebes and Phocis was so." He is careful to 
 point out that the whole force of the argument depends on 
 the implied assumption of a universal proposition which covers 
 both cases, such as " wars between neighbours are bad things." 
 Hence he calls such appeals to example " rhetorical " reasoning, 
 because the politician is accustomed to leave his hearers to 
 supply the relevant universal consideration for themselves. 
 Theory of Knowledge. Here, as everywhere in Aristotle's
 
 CLASSIFICATION OF THE SCIENCES 27 
 
 philosophy, we are confronted by an initial and insuperable 
 difficulty. Aristotle is always anxious to insist on the dif- 
 ference between his own doctrines and those of Plato, and his 
 bias in this direction regularly leads him to speak as though 
 he held a thorough -going naturalistic and empirical theory with 
 no " transcendental moonshine " about it. Yet his final con- 
 clusions on all points of importance are hardly distinguishable 
 from those of Plato except by the fact that, as they are so 
 much at variance with the naturalistic side of his philosophy, 
 they have the appearance of being sudden lapses into an 
 alogical mysticism. We shall find the presence of this " fault " 
 more pronouncedly in his metaphysics, psychology, and ethics 
 than in his theory of knowledge, but it is not absent from any 
 part of his philosophy. He is everywhere a Platonist malgrd 
 lui, and it is just the Platonic element in his thought to which 
 it owes its hold over men's minds. 
 
 Plato's doctrine on the subject may be stated with enough 
 accuracy for our purpose as follows. There is a radical dis- 
 tinction between sense-perception and scientific knowledge. 
 A scientific truth is exact and definite, it is also true once and 
 for all, and never becomes truer or falser with the lapse of 
 time. This is the character of the propositions of the science 
 which Plato regarded as the type of what true science ought to 
 be, pure mathematics. It is very different with the judgments 
 which we try to base on our sense-perceptions of the visible 
 and tangible world. The colours, tastes, shapes of sensible 
 things seem different to different percipients, and moreover they 
 are constantly changing in incalculable ways. We can never be 
 certain that two lines which seem to our senses to be equal 
 are really so ; it may be that the inequality is merely too 
 slight to be perceptible to our senses. No figure which we 
 can draw and see actually has the exact properties ascribed by 
 the mathematician to a circle or a square. Hence Plato con- 
 cludes that if the word science be taken in its fullest sense, 
 there can be no science about the world which our senses 
 reveal. We can have only an approximate knowledge, a 
 knowledge which is after all, at best, probable opinion. The 
 objects of which the mathematician has certain, exact, and 
 final knowledge cannot be anything which the senses reveal 
 They are objects of thought, and the function of visible models
 
 28 ARISTOTLE 
 
 and diagrams in mathematics is not to present examples of 
 them to us, but only to show us imperfect approximations to 
 them and so to " remind " the soul of objects and relations 
 between them which she has never cognised with the bodily 
 senses. Thus mathematical straightness is never actually 
 beheld, but when we see lines of less and more approximate 
 straightness we are " put in mind " of that absolute straight- 
 ness to which sense-perception only approximates. So in the 
 moral sciences, the various " virtues " are not presented in 
 their perfection by the course of daily life. We do not meet 
 with men who are perfectly brave or just, but the experience 
 that one man is braver or juster than another " calls into our 
 mind " the thought of the absolute standard of courage or 
 justice implied in the conviction that one man comes nearer 
 to it than another, and it is these absolute standards which 
 are the real objects of our attention when we try to define the 
 terms by which we describe the moral life. This is the 
 " epistemological " side of the famous doctrine of the " Ideas." 
 The main points are two, (1) that strict science deals through- 
 out with objects and relations between objects which are of a 
 purely intellectual or conceptual order, no sense-data entering 
 into their constitution ; (2) since the objects of science are of 
 this character, it follows that the "Idea" or "concept" or 
 "universal" is not arrived at by any process of "abstracting" 
 from our experience of sensible things the features common to 
 them all. As the particular fact never actually exhibits the 
 " universal " except approximately, the " universal " cannot be 
 simply disentangled from particulars by abstraction. As Plato 
 puts it, it is " apart from " particulars, or, as we might reword 
 his thought, the pure concepts of science represent "upper 
 limits " to which the comparative series which we can form out 
 of sensible data continually approximate but do not reach them. 
 In his theory of knowledge Aristotle begins by brushing aside 
 the Platonic view. Science requires no such " Ideas," trans- 
 cending sense-experience, as Plato had spoken of; they are, in 
 fact, no more than " poetic metaphors." What is required for 
 science is not that there should be a "one over and above the 
 many " (that is, such pure concepts, unrealised in the world of 
 actual perception, as Plato had spoken of), but only that it 
 should be possible to predicate one term universally of many
 
 CLASSIFICATION OF THE SCIENCES 29 
 
 others. This, by itself, means that the " universal " is looked 
 on as a mere residue of the characteristics found in each member 
 of a'group, got by abstraction, i.e. by leaving out of view the 
 characteristics which are peculiar to some of the group and re- 
 taining only those which are common to all. If Aristotle had 
 held consistently to this point of view, his theory of knowledge 
 would have been a purely empirical one. He would have had 
 to say that, since all the objects of knowledge are particular 
 facts given in sense-perception, the universal laws of science are 
 a mere convenient way of describing the observed uniformities 
 in the behaviour of sensible things. But, since it is obvious 
 that in pure mathematics we are not concerned with the actual 
 relations between sensible data or the actual ways in which 
 they behave, but with so-called " pure cases " or ideals to which 
 the perceived world only approximately conforms, he would also 
 have had to say that the propositions of mathematics are not 
 strictly true. In modern times consistent empiricists have said 
 this, but it is not a position possible to one who had passed 
 twenty years in association with the mathematicians of the 
 Academy, and Aristotle's theory only begins in naturalism to 
 end in Platonism. We may condense its most striking positions 
 into the following statement. By science we mean proved 
 knowledge. And proved knowledge is always "mediated"; 
 it is the knowledge of conclusions from premisses. A truth 
 that is scientifically known does not stand alone. The " proof" 
 is simply the pointing out of the connection between the truth 
 we call the conclusion, and other truths which we call the pre- 
 misses of our demonstration. Science points out the reason 
 why of things, and this is what is meant by the Aristotelian 
 principle that to have science is to know things through their 
 causes or reasons why. In an ordered digest of scientific truths, 
 the proper arrangement is to begin with the simplest and most 
 widely extended principles and to reason down, through succes- 
 sive inferences, to the most complex propositions, the reason why 
 of which can only be exhibited by long chains of deductions. This 
 is the order of logical dependence, and is described by Aristotle 
 aa reasoning from what is " more knowable in its own nature," * 
 
 1 This siinpfe expression acquires a mysterious appearance in mediaeval 
 philosophy from the standing mistranslation notiora naturce, " better 
 known to nature. "
 
 30 ARISTOTLE 
 
 the simple, to what is usually " more familiar to us," because 
 less removed from the infinite wealth of sense-perception, the 
 complex. In discovery we have usually to reverse the pro- 
 cess and argue from "the familiar to us," highly complex 
 facts, to " the more knowable in its own nature," the simpler 
 principles implied in the facts. 
 
 It follows that Aristotle, after all, admits the disparateness 
 of sense-perception and scientific knowledge. Sense-perception 
 of itself never gives us scientific truth, because it can only assure 
 us that a fact is so ; it cannot explain the fact by showing its 
 connection with the rest of the system of facts, "it does not 
 give the reason for the fact." Knowledge of perception is 
 always " immediate," and for that very reason is never scientific. 
 If we stood on the moon and saw the earth interposing between 
 us and the sun, we should still not have scientific knowledge 
 about the eclipse, because " we should still have to ask for the 
 reason why." (In fact, we should not know the reason why 
 without a theory of light including the proposition that light- 
 waves are propagated in straight lines and several others.) 
 Similarly Aristotle insists that Induction does not yield scientific 
 truth. " He who makes an induction points out something, 
 but does not demonstrate anything." 
 
 For instance, if we know that each species of animal which 
 is without a gall is long-lived, we may make the induction that 
 all animals without a gall are long-lived, but in doing so we 
 have got no nearer to seeing why or how the absence of a gall 
 makes for longevity. The question which we may raise in 
 science may all be reduced to four heads, (1) Does this thing 
 exist 1 (2) Does this event occur ? (3) If the thing exists, precisely 
 what is it ? and (4) If the event occurs, why does it occur ? and 
 science has not completed its task unless it can advance from 
 the solution of the first two questions to that of the latter two. 
 Science is no mere catalogue of things and events, it consists 
 of inquiries into the " real essences " and characteristics of things 
 and the laws of connection between events. 
 
 Looking at scientific reasoning, then, from the point of view 
 of its formal character, we may say that all science consists in 
 the search for "middle terms" of syllogisms, by which to 
 connect the truth which appears as a conclusion with the less 
 complex truths which appear as the premisses from which it is
 
 CLASSIFICATION OF THE SCIENCES 31 
 
 drawn. When we ask, " does such a thing exist ? " or " does 
 such an event happen 1 " we are asking, " is there a middle term 
 which can connect the thing or event in question with the rest 
 of known reality ? " Since it is a rule of the syllogism that the 
 middle term must be taken universally, at least once in the 
 premisses, the search for middle terms may also be described as 
 the search for universals, and we may speak of science as 
 knowledge of the universal interconnections between facts and 
 events. 
 
 A science, then, may be analysed into three constituents. 
 These are: (1) a determinate class of objects which form the 
 subject-matter of its inquiries. In an orderly exhibition of 
 the contents of the science, these appear, as in Euclid, as the 
 initial data about which the science reasons ; (2) a number of 
 principles, postulates, and axioms, from which our demonstra- 
 tions must start. Some of these will be principles employed 
 in all scientific reasoning. Others will be specific to the sub- 
 ject-matter with which a particular science is concerned ; 
 (3) certain characteristics of the objects under study which can 
 be shown by means of our axioms and postulates to follow from 
 our initial definitions, the accidentia per se of the objects 
 defined. It is these last which are expressed by the con- 
 clusions of scientific demonstration. We are said to know 
 scientifically that B is true of A when we show that this 
 follows, in virtue of the principles of some science, from the 
 initial definition of A. Thus if we convinced ourselves that 
 the sum of the angles of a plane triangle is equal to two right 
 angles by measurement, we could not be said to have scientific 
 knowledge of the proposition. But if we show that the same 
 proposition follows from the definition of a plane triangle by re- 
 peated applications of admitted axioms or postulates of geometry, 
 our knowledge is genuinely scientific. We now know that it 
 is so, and we see why it is so ; we see the connection of this 
 truth with the simple initial truths of geometry. 
 
 This leads us to the consideration of the most characteristic 
 point of Aristotle's whole theory. Science is demonstrated 
 knowledge, that is, it is the knowledge that certain truths 
 follow from still simpler truths. Hence the simplest of all the 
 truths of any science cannot themselves be capable of being 
 known by inference. You cannot infer that the axioms of 
 
 C
 
 32 ARISTOTLE 
 
 geometry are true because its conclusions are true, since the 
 truth of the conclusions is itself a consequence of the truth of 
 the axioms. Nor yet must you ask for demonstration of the 
 axioms as consequences of still simpler premisses, because if all 
 truths can be proved, they ought to be proved, and you would 
 therefore require an infinity of successive demonstrations to 
 prove anything whatever. But under such conditions all know- 
 ledge of demonstrated truth would be impossible. The first 
 principles of any science must therefore be indemonstrable. 
 They must be known, as facts of sense-perception are known, 
 immediately and not mediately. How then do we come by our 
 knowledge of them ? Aristotle's answer to this question appears 
 at first sight curiously contradictory. He seems to say that 
 these simplest truths are apprehended intuitively, or on in- 
 spection, as self-evident by Intelligence or Mind. On the other 
 hand, he also says that they are known to its as a result of 
 induction from sense-experience. Thus he seems to be either a 
 Platonist or an empiricist, according as you choose to remember 
 one set of his utterances or another, and this apparent incon- 
 sistency has led to his authority being claimed in their favour 
 by thinkers of the most widely different types. But more 
 careful study will show that the seeming confusion is due to 
 the fact that he tries to combine in one statement his answers 
 to two quite different questions, (1) how we come to reflect 
 on the axioms, (2) what evidence there is for their truth. To 
 the first question he replies, " by induction from experience," 
 and so far he might seem to be a precursor of John Stuart 
 Mill. Successive repetitions of the same sense-perceptions give 
 rise to a single experience, and it is by reflection on experience 
 that we become aware of the most ultimate simple and uni- 
 versal principles. We might illustrate his point by considering 
 how the thought that two and two are four may be brought 
 before a child's mind. We might first take two apples, and 
 two other apples and set the child to count them. By repeat- 
 ing the process with different apples we may teach the child 
 to dissociate the result of the counting from the particular 
 apples employed, and to advance to the thought, "any two 
 apples and any two other apples make four apples." Then we 
 might substitute pears or cherries for the apples, so as to 
 suggest the thought, "two fruits and two fruits make four
 
 CLASSIFICATION OF THE SCIENCES 33 
 
 fruits." And by similar methods we should in the end evoke 
 the thought, ," any two objects whatever and any other two 
 objects whatever make four objects." This exactly illustrates 
 Aristotle's conception of the function of induction, or comparison 
 of instances, in fixing attention on a universal principle of 
 which one had not been conscious before the comparison was 
 made. 
 
 Now comes in the point where Aristotle differs wholly from 
 all empiricists, later and earlier. Mill regards the instances 
 produced in the induction as having a double function ; they 
 not merely fix the attention on the principle, they also are the 
 evidence of its truth. This gives rise to the greatest difficulty 
 in his whole logical theory. Induction by imperfect enumera- 
 tion is pronounced to be (as it clearly is) fallacious, yet the 
 principle of the uniformity of Nature which Mill regards as the 
 ultimate premiss of all science, is itself supposed to be proved 
 by this radically fallacious method. Aristotle avoids a similar 
 inconsistency by holding that the sole function of the induction 
 is to fix our attention on a principle which it does not prove. 
 He holds that ultimate principles neither permit of nor require 
 proof. When the induction has done its work in calling at- 
 tention to the principle, you have to see for yourself that the 
 principle is true. You see that it is true by immediate in- 
 spection just as in sense-perception you have to see that the 
 colour before your eyes is red or blue. This is why Aristotle 
 holds that the knowledge of the principles of science is not 
 itself science (demonstrated knowledge), but what he calls in- 
 telligence, and we may call intellectual intuition. Thus his 
 doctrine is sharply distinguished not only from empiricism 
 (the doctrine that universal principles are proved by particular 
 facts), but also from all theories of the Hegelian type which 
 regard the principles and the facts as somehow reciprocally 
 proving each other, and from the doctrine of some eminent 
 modern logicians who hold that " self-evidence " is not required 
 in the ultimate principles of science, as we are only concerned 
 in logic with the question what consequences follow from our 
 initial assumptions, and not with the truth or falsehood of the 
 assumptions themselves. 
 
 The result is that Aristotle does little more than repeat the 
 Platonic view of the nature of science. Science consists of de-
 
 34 ARISTOTLE 
 
 ductiona from universal principles which sensible experience 
 "suggests," but into which, as they are apprehended by a 
 purely intellectual inspection, no sense-data enter as constituents. 
 The apparent rejection of "transcendental moonshine" has, 
 after all, led to nothing. The only difference between Plato 
 and his scholar lies in the clearness of intellectual vision which 
 Plato shows when he expressly maintains in plain words 
 that the universals of exact science are not " in " our sense- 
 perceptions and therefore to be extracted from them by a pro- 
 cess of abstraction, but are " apart from " or " over " them, and 
 form an ideal system of interconnected concepts which the ex- 
 periences of sense merely " imitate " or make approximation to. 
 One more point remains to be considered to complete our 
 outline of the Aristotelian theory of knowledge. The sciences 
 have " principles " which are discerned to be true by immediate 
 inspection. But what if one man professes to see the self- 
 evident truth of such an alleged principle, while another is 
 doubtful of its truth, or even denies it? There can be no 
 question of silencing the objector by a demonstration, since no 
 genuine simple principle admits of demonstration. All that 
 can be done, e.g. if a man doubts whether things equal to the 
 same thing are equal to one another, or whether the law of 
 contradiction is true, is to examine the consequences of a denial 
 of the axiom and to show that they include some which 
 are false, or which your antagonist at least considers false. In 
 this way, by showing the falsity of consequences which follow 
 from the denial of a given 'principle," you indirectly establish 
 its truth. Now reasoning of this kind differs from " science " 
 precisely in the point that you take as your major premiss, not 
 what you regard as true, but the opposite thesis of your anta- 
 gonist, which you regard as false. Your object is not to prove 
 a true conclusion but to show your opponent that his premisses 
 lead to false conclusions. This is " dialectical " reasoning in 
 Aristotle's sense of the word, i.e. reasoning not from your own 
 but from some one else's premisses. Hence the chief philoso- 
 phical importance which Aristotle ascribes to " dialectic " is 
 that it provides a method of defending the uudemonstrable 
 axioms against objections. Dialectic of this kind became highly 
 important in the mediaeval Aristotelianism of the schoolmen, 
 with whom it became a regular method, as may be seen e.g. in
 
 FIRST PHILOSOPHY 35 
 
 the Summa of St. Thomas, to begin their consideration of a 
 doctrine by a preliminary rehearsal of all the arguments they 
 could find or devise against the conclusion they meant to adopt. 
 Thus the first division of any article in the Summa Theologice 
 of Thomas is regularly constituted by arguments based on the 
 premisses of actual or possible antagonists, and is strictly dia- 
 lectical. (To be quite accurate Aristotle should, of course, 
 have observed that this dialectical method of defending a prin- 
 ciple becomes useless in the case of a logical axiom which is 
 presupposed by all deduction. For this reason Aristotle falls 
 into fallacy when he tries to defend the law of contradiction by 
 dialectic. It is true that if the law be denied, then any and 
 every predicate may be indifferently ascribed to any subject. 
 But until the law of contradiction has been admitted, you 
 have no right to regard it as absurd to ascribe all predicates 
 indiscriminately to all subjects. Thus, it is only assumed laws 
 which are not ultimate laws of logic that admit of dialectical 
 justification. If a truth is so ultimate that it has either to be 
 recognised by direct inspection or not at all, there can be no 
 arguing at all with one who cannot or will not see it.) 
 
 CHAPTER III 
 
 FIRST PHILOSOPHY 
 
 FIRST Philosophy is defined by Aristotle as a "science which 
 considers What Is simply in its character of Being, and the 
 properties which it has as such." That there is, or ought to 
 be, such a science is urged on the ground that every " special " 
 science deals only with some restricted department of what is, 
 and thus considers its subject-matter not universally in its char- 
 acter of being, or being real, but as determined by some more 
 special condition. Thus, First Philosophy, the science which 
 attempts to discover the most ultimate reasons of, or grounds 
 for, the character of things in general cannot be identified with 
 any of the " departmental " sciences. The same consideration 
 explains why it is " First Philosophy " which has to disentangle 
 the "principles" of the various sciences, and defend them
 
 36 ARISTOTLE 
 
 by dialectic against those who impugn them. It is no part 
 of the duty of a geometer or a physicist to deal with objec- 
 tions to such universal principles of reasoning as the law of 
 contradiction. They may safely assume such principles; if 
 they are attacked, it is not by specifically geometrical or physical 
 considerations that they can be defended. Even the " principles 
 of the special sciences " have not to be examined and defended 
 by the special sciences. They are the starting-points of the 
 sciences which employ them ; these sciences are therefore justified 
 in requiring that they shall be admitted as a condition of geo- 
 metrical, or physical, or biological demonstrations. If they are 
 called in question, the defence of them is the business of logic. 
 
 First Philosophy, then, is the study of " What Is simply as 
 such," the universal principles of structure without which there 
 could be no ordered system of knowable objects. But the word 
 " ia " has more than one sense. There are as many modes of 
 being as there are types of predication. " Substances," men, 
 horses, and the like, have their own specific mode of being 
 they are things; qualities, such as green or sweet, have a different 
 mode of being they are not things, but " affections " or 
 " attributes " of things. Actions, again, such as building, killing, 
 are neither things nor yet " affections " of things ; their mode 
 of being is that they are processes which produce or destroy 
 things. First Philosophy is concerned with the general character 
 of all these modes of being, but it is specially concerned with 
 that mode of being which belongs to substances. For this is 
 the most primary of all modes of being. We had to introduce 
 a reference to it in our attempt to say what the mode of being 
 of qualities and actions is, and it would have been the same 
 had our illustrations been drawn from any other " categories." 
 Hence the central and special problem of First Philosophy is 
 to analyse the notion of substance and to show the causes of 
 the existence of substances. 
 
 Next, we have to note that the word " substance " itself 
 haa. two senses. When we spoke of substance as one of the 
 categories we were using it in a secondary sense. We meant 
 by substances " horse," " man," and the rest of the " real 
 kinds " which we find in Nature, and try to reproduce in a 
 scientific classification. In this sense of the word " substances " 
 are a special class of predicates, as when we affirm of Plato
 
 FIRST PHILOSOPHY 37 
 
 that he is a man, or of Bucephalus that he is a horse. But in 
 the primary sense a substance means an absolutely individual 
 thing, " this man," or " this horse." We may therefore define 
 primary substances from the logician's point of view by saying 
 that they can be only subjects of predication, never predicates. 
 Or again, it is peculiar to substances, that while remaining 
 numerically one a substance admits of incompatible determin- 
 ations, as Socrates, remaining one and the same Socrates, is 
 successively young and old. This is not true of " qualities," 
 " actions," and the rest. The same colour cannot be first white 
 and then black ; the same act cannot be first bad and then 
 good. Thus we may say that individual substances are the 
 fixed and permanent factors in the world of mutability, the 
 invariants of existence. Processes go on in them, they run 
 the gamut of changes from birth to decay, processes take place 
 among them, they act on and are acted on by one another, they 
 fluctuate in their qualities and their magnitude, but so long 
 as a substance exists it remains numerically one and the same 
 throughout all these changes. Their existence is the first 
 and most fundamental condition of the existence of the universe, 
 since they are the bearers of all qualities, the terms of all 
 relations, and the agents and patients in all interaction. 
 
 The point to note is that Aristotle begins his investigation 
 into the structure of What Is and the causes by which it is 
 produced by starting from the existence of individual things 
 belonging to the physical order and perceived by the senses. 
 About any such thing we may ask two questions, (1) into 
 what constituent factors can it be logically analysed ? (2) and 
 how has it come to exhibit the character which our analysis 
 shows it to have 1 The answer to these questions will appear 
 from a consideration of two standing antitheses which run 
 through Aristotle's philosophy, the contrast between Matter and 
 Form, and that between Potential and Actual, followed by a 
 recapitulation of his doctrine of the Four Causes, or four senses 
 of the word Cause. 
 
 Matter and Form- Consider any completely developed 
 individual thing, whether it is the product of human manu- 
 facture, as a copper bowl, or of natural reproduction, as 
 an oak-tree or a borse. We shall see at once that the bowl 
 is like other articles made of the same metal, candlesticks,
 
 88 ARISTOTLE 
 
 coal-vases, in being made of the same stuff, and unlike them 
 in having the special shape or structure which renders it fit 
 for being used as a bowl and not for holding a candle or 
 containing coals. So a botanist or a chemist will tell you that 
 the constituent tissues of an oak or horse, or the chemical 
 elements out of which these tissues are built up are of the 
 same kind as those of an ash or an ox, but the oak differs 
 from the ash or the horse from the ox in characteristic structure. 
 We see thus that in any individual thing we can distinguish 
 two components, the stuff of which it consists which may be 
 identical in kind with the stuff of which things of a very 
 different kind consist and the structural law of formation 
 or arrangement which is peculiar to the "special'' kind of 
 thing under consideration. In the actual individual thing 
 these two are inseparably united; they do not exist side 
 by side, as chemists say the atoms of hydrogen and oxygen 
 do in a drop of water; the law of organisation or structure 
 is manifested in and through the copper, or the various tissues 
 of the living body. Aristotle expresses this by saying that 
 you can distinguish two aspects in an individual, its Matter, 
 (hyle, materia) and its Form (eidos, forma). The individual 
 is the matter as organised in accord with a determinate 
 principle of structure, the form. Of these terms, the former, 
 hyle (materia, matter) means literally timber, and more 
 specifically ship's timbers, and his selection of it to mean 
 what is most exactly rendered by our own word "stuff may 
 perhaps be due to a reminiscence of an old Pythagorean fancy 
 which looked on the universe as a ship. The word for form 
 is the same as Plato's, and its philosophical uses are closely 
 connected with its mathematical sense, " regular figure," also 
 a Pythagorean technicality which still survives in certain 
 stereotyped phrases in Euclid. Aristotle extends the analysis 
 into Matter and Form by analogy beyond the range of indi- 
 vidual substances to everything in which we can distinguish 
 a relatively indeterminate "somewhat" and a law or type 
 of order and arrangement giving it determination. Thus if 
 you consider the relatively fixed or " formed " character of a 
 man in adult life, we may look upon this character as pro- 
 duced out of the " raw material " of tendencies and dispositions, 
 which have received a specific development along definite
 
 FIRST PHILOSOPHY 39 
 
 lines, according to the kind of training to which the mind has 
 been subjected in the " formative " period of its growth. We 
 may therefore speak of native disposition as the matter or 
 stuff of which character is made, and the practical problem 
 of education is to devise a system of training which shall 
 impress on this matter precisely the form required if the grown 
 man is to be a good citizen of a good state. Since a man's 
 character itself is not a substance but a complex of habits or 
 fixed ways of reacting upon suggestions coming from the world 
 around him, this is a good instance of the extension of the 
 antithesis of Matter and Form beyond the category of sub- 
 stance. We see then that Matter in the Aristotelian sense 
 must not be confounded with body; the relatively undeter- 
 mined factor which receives completer determination by the 
 structural law or Form is Matter, whether it is corporeal or not. 
 This comes out with particular clearness in the metaphysical 
 interpretation put on the logical process of definition by genus 
 and difference. When I define any real kind by specifying 
 a higher and wider class of which it is a sub-kind, and adding 
 the peculiar characteristics which distinguish the sub-kind 
 under consideration from the other sub-kinds of the same 
 genus, the genus may be said to stand to the " differences " 
 as Matter, the relatively indeterminate, to the Form which 
 gives it its structure. 
 
 We further observe that Matter and Form are strictly cor- 
 relative. The matter is called so relatively to the form which 
 gives it further determination. When the words are used in 
 their strictest sense, with reference to an individual thing, the 
 Form is taken to mean the last determination by which the 
 thing acquires its complete character, and the Matter is that 
 which has yet to receive this last determination. Thus in the 
 case of a copper globe, the spherical figure is said to be its 
 Form, the copper its material. In the case of the human body, 
 the Matter is the various tissues, muscles, bones, skin, &c. 
 But each of these things which are counted as belonging to the 
 Matter of the globe or the human body has, according to Aris- 
 totle, a development behind it. Copper is not an " element " 
 but a specific combination of " elements," and the same thing 
 is even more true of the highly elaborate tissues of the living 
 body. Thus what is Matter relatively to the globe or living
 
 40 ARISTOTLE 
 
 body is Matter already determined by Form if we consider it 
 relatively to its own constituents. The so-called " elements " 
 of Empedocles, earth, water, air, fire, are the matter of all 
 chemical compounds, the Form of each compound being ita 
 specific law of composition ; the immediate or " proximate " 
 Matter of the tissues of the animal body is, according to Aris- 
 totle's biology, the "superfluous" blood of the female parent, 
 out of which the various tissues in the offspring iare developed, 
 and the Matter of this blood is in turn the various substances 
 which are taken into the body of the parent as food and con- 
 verted by assimilation into blood. Their Matter, once more, 
 is the earth, air, fire, and water of which they are composed. 
 Thus at every stage of a process of manufacture or growth a 
 fresh Form is superinduced <on, or developed within, a Matter 
 which is already itself a combination of Matter and Form 
 relatively to the process by which it has itself been originated. 
 Fully thought out, such a view would lead to the conclusion 
 that in the end the simple ultimate matter of all individual 
 things is one and the same throughout the universe, and has 
 absolutely no definite structure at all. The introduction of 
 Form or determinate structure of any kind would then have to 
 be thought of as coining from an outside source, since structure- 
 less Matter cannot be supposed to give itself all sorts of specific 
 determinations, as has been demonstrated in our own times by 
 the collapse of the " Synthetic Philosophy." Aristotle avoids 
 the difficulty by holding that " pure Matter " is a creation of 
 our thought. In actual fact the crudest form in which matter 
 is found is that of the " elements." Since the transmutability 
 of the " elements " is an indispensable tenet in Aristotle's 
 Physics, we cannot avoid regarding earth, water, fire, air, as 
 themselves determinations by specific Form of a still simpler 
 Matter, though this " prime Matter " " all alone, before a rag of 
 Form is on," is never to be found existing in its simplicity. 1 
 
 The Potential and the Actual. So far we have been look- 
 ing at the analysis of the individual thing, as the current jargon 
 puts it, statically ; we have arrived at the antithesis of 
 i Hudibras, Pt. 1, Canto 1, 560. 
 
 " He had First Matter seen undressed ; 
 
 He took her naked all alone, 
 
 Before one rag of Form was on."
 
 FIRST PHILOSOPHY 41 
 
 Matter and Form by contrasting an unfinished condition of 
 anything with its finished condition. But we may study the 
 same contrast dynamically, with special reference to the process 
 of making or growth by which the relatively undetermined or 
 unfinished becomes determined or finished. The contrast of 
 Matter with Form then passes into the contrast between 
 Potentiality and Actuality. What this antithesis means we 
 can best see from the case of the growth of a living organism. 
 Consider the embryos of two animals, or the seeds of two 
 plants. Even a botanist or a physiologist may be unable to 
 pronounce with certainty on the species to which the germ sub- 
 mitted to him belongs, and chemical analysis may be equally at 
 a loss. Even at a later stage of development, the embryo of 
 one vertebrate animal may be indistinguishable from that of 
 another. Yet it is certain that one of two originally indis- 
 tinguishable germs will grow into an oak and the other into an 
 elm, or one into a chimpanzee and the other into a man. How- 
 ever indistinguishable, they therefore may be said to have 
 different latent tendencies or possibilities of development within 
 them. Hence we may say of a given germ, " though this is 
 not yet actually an oak, it is potentially an oak," meaning not 
 merely that, if uninterfered with, it will in time be an oak, 
 but also that by no interference 'can it be made to grow into 
 an elm or a beech. So we may look upon all processes of pro- 
 duction or development as processes by which what at first 
 possessed only the tendency to grow along certain lines or to 
 be worked up into a certain form, has become actually endowed 
 with the character to which it possessed the tendency. The 
 acorn becomes in process of time an actual oak, the baby an 
 actual man, the copper is made into an actual vase, right educa- 
 tion brings out into active exercise the special capacities of the 
 learner. Hence the distinction between Matter and Form may 
 also be expressed by saying that the Matter is the persistent 
 underlying substratum in which the development of the Form 
 takes place, or that the individual when finally determined by 
 the Form is the Actuality of which the undeveloped Matter 
 was the Potentiality. The process of conception, birth, and 
 growth to maturity in Nature, or of the production of a finished 
 article by the " arts " whose business it is to " imitate " Nature, 
 may be said to be one of continuous advance towards the
 
 42 ARISTOTLE 
 
 actual embodiment of a Form, or law of organisation, in a 
 Matter having the latent potentiality of developing along those 
 special lines. When Aristotle is speaking most strictly he 
 distinguishes the process by which a Form is realised, which he 
 calls Energeia, from the manifestation of the realised Form, 
 calling the latter Entelechy (literally "finished" or "com- 
 pleted " condition). Often, however, he uses the word Energeia 
 more loosely for the actual manifestation of the Form itself, 
 and in this he is followed by the scholastic writers, who render 
 Energeia by actus or actus purus. 
 
 One presupposition of this process must be specially noted. 
 It is not an unending process of development of unrealised 
 capacities, but always has an End in the perfectly simple 
 sense of a last stage. We see this best in the case of growth. 
 The acorn grows into the sapling and the sapling into the oak, 
 but there is nothing related to the oak as the oak is to the 
 sapling. The oak does not grow into something else. The 
 process of development from potential to actual in this special 
 case comes to an end with the emergence of the mature oak. 
 In the organic world the end or last state is recognised by the 
 fact that the organism can now exercise the power of repro- 
 ducing its like. This tendency of organic process to culminate 
 in a last stage of complete maturity is the key to the treat- 
 ment of the problem of the " true end " of life in Aristotle's 
 Ethics. 
 
 The Four Causes. The conception of the world involved 
 in these antitheses of Form and Matter, Potential and Actual, 
 finds its fullest expression in Aristotle's doctrine of the Four 
 Causes or conditions of the production of things. This doctrine 
 is looked on by Aristotle as the final solution of the problem 
 which had always been the central one for Greek philosophy, 
 What are the causes of the world-order 1 ? All the previous 
 philosophies he regards as inadequate attempts to formulate 
 the answer to this question which is only given completely by 
 his own system. Hence the doctrine requires to be stated 
 with some fullness. We may best approach it by starting from 
 the literal meaning of the Greek terms aitia, aition, which 
 Aristotle uses to convey the notion of cause. Aition is properly 
 an adjective used substantially, and means "that on which 
 the legal responsibility for a given state of affairs can be laid."
 
 FIRST PHILOSOPHY 43 
 
 Similarly aitia, the substantive, means the " credit " for good 
 or bad, the legal " responsibility," for an act. Now when we 
 ask, "what is responsible for the fact that such and such 
 a state of things now exists ? " there are four partial answers 
 which may be given, and each of these corresponds to one of 
 the " causes." A complete answer requires the enumeration 
 of them all. We may mention (1) the matter or material 
 cause of the thing, (2) the law according to which it has grown 
 or developed, the form or formal cause, (3) the agent with 
 whose initial impulse the development began the "starting- 
 point of the process," or, as the later Aristotelians call it, the 
 efficient cause, (4) the completed result of the whole process, 
 which is present in the case of human manufacture as a pre- 
 conceived idea determining the maker's whole method of 
 handling his material, and in organic development in Nature 
 as implied in and determining the successive stages of growth 
 the end or final cause. If any one of these had been 
 different, the resultant state of things would also have been 
 different. Hence all four must be specified in completely 
 accounting for it. Obvious illustrations can be given from 
 artificial products of human skill, but it seems clear that it 
 was rather reflection on the biological process of reproduction 
 and growth which originally suggested the analysis. Suppose 
 we ask what was requisite in order that there should be now an 
 oak on a given spot. There must have been (1) a germ from 
 which the oak has grown, and this germ must have had the 
 latent tendencies towards development which are characteristic 
 of oaks. This is the material cause of the oak. (2) This 
 germ must have followed a definite law of growth ; it must 
 have had a tendency to grow in the way characteristic of oaks 
 and to develop the structure of an oak, not that of a plane or 
 an ash. This is form or formal cause. (3) Also the germ of 
 the oak did not come from nowhere ; it grew on a parent oak. 
 The parent oak and its acorn-bearing activity thus constitute 
 the efficient cause of the present oak. (4) And there must be 
 a final stage to which the whole process of growth is relative, 
 in which the germ or sapling is no longer becoming but is an 
 adult oak bearing fresh acorns. This is the end of the process. 
 One would not be going far wrong in saying that Aristotle's 
 biological cast of thought leads him .to conceive of this "end"
 
 44 ARISTOTLE 
 
 in the case of reproduction as a sub-conscious purpose, just as 
 the workman's thought of the result to be attained by his 
 action forms a conscious directing purpose in the case of manu- 
 facture. Both in Nature and in "art" the "form," the 
 " efficient cause," and the " end " tend to coalesce. Thus in 
 Nature " a man begets a man," organic beings give birth to 
 other organic beings of the same kind, or, in the technical 
 language of the Aristotelian theory of Causation, the efficient 
 cause produces, as the " end " of its action, a second being 
 having the same " form '' as itself, though realised in different 
 "matter," and numerically distinct from itself. Thus the 
 efficient cause (i.e. the parent) is a " form " realised in 
 matter, and the " end " is the same " form " realised in other 
 matter. So in " products of art " the true " source of the 
 process " is the " form " the realisation of which is the " end " 
 or final cause, only with this difference, that as efficient cause 
 the "form " exists not in the material but by way of "idea" 
 or " representation " in the mind of the craftsman. A house 
 does not produce another house, but the house as existing in 
 " idea " in the builder's mind sets him at work building, and 
 so produces a corresponding house in brick or stone. Thus 
 the ultimate opposition is between the " cause as matter," a 
 passive and inert substratum of change and development and 
 the " formal " cause which, in the sense just explained, is one 
 with both the "efficient" or starting-point, and the "end" 
 or goal of development. It will, of course, be seen that 
 individual bearers of " forms " are indispensable in the theory ; 
 hence the notion of activity is essential to the causal relation. 
 It is a relation between things, not between events. Aristotle 
 has no sense of the word cause corresponding to Mill's con- 
 ception of a cause as an event which is the uniform precursor 
 of another event. 
 
 Two more remarks may be made in this connection. (1) 
 The prominence of the notion of "end" gives Aristotle's 
 philosophy a thorough-going " teleological " character. God 
 and Nature, he tells us, do nothing aimlessly. We should 
 probably be mistaken if we took this to mean that " God and 
 Nature " act everywhere with conscious design. The meaning 
 is rather that every natural process has a last stage in which 
 the " form " which was to begin with present in the agent or
 
 FIRST. PHILOSOPHY 45 
 
 " source of change " is fully realised in the matter in which 
 the agent has set up the process of change. The normal] thing 
 is e.g. for animals to reproduce " their kind " ; if the reproduc- 
 tion is imperfect or distorted, as in monstrous births, this is 
 an exception due to the occasional presence in "matter" of 
 imperfections which hinder the course of development, and 
 must be regarded as " contrary to the normal course of Nature." 
 So hybrid reproduction is exceptional and " against Nature," 
 and this is shown by the sterility of hybrids, a sort of lesser 
 monstrosity. Even females, being "arrested developments," 
 are a sort of still minor deviation from principle. (2) It may 
 just be mentioned that Aristotle has a classification of efficient 
 causes under the three heads of Nature, Intelligence (or Man), 
 and Chance. The difference between Nature and Man or 
 Intelligence as efficient causes has already been illustrated. It 
 is that in causation by Nature, such as sexual reproduction, or 
 the assimilation of nutriment, or the conversion of one element 
 into another in which Aristotle believed, the form which is 
 superinduced on the matter by the agent already exists in the 
 agent itself as its form. The oak springs from a parent oak, 
 the conversion of nutriment into organic tissue is due to the 
 agency of already existing organic tissue. In the case of human 
 intelligence or art, the " form " to be superinduced exists in 
 the agent not as his characteristic form, but by way of repre- 
 sentation, as a contemplated design. The man who builds a 
 house is not himself a house ; the form characteristic of a house 
 is very different from that characteristic of a man, but it is 
 present in contemplation to the builder before it is embodied 
 in the actual house. A word may be added about the third 
 sort of efficient causality, causation by chance. This is confined 
 to cases which are exceptions from the general course of Nature, 
 remarkable coincidences. It is what we may call " simulated 
 purposiveness." When something in human affairs happens 
 in a way which subserves the achievement of a result but was 
 not really brought about by any intention to secure the result, 
 we speak of it as a remarkable coincidence. Thus it would be 
 a coincidence if a man should be held to ransom by brigands 
 And his best friend should, without knowing anything of the 
 matter, turn up on the spot with the means of ransoming him. 
 The events could not have happened more opportunely if they
 
 46 ARISTOTLE 
 
 had been planned, and yet they were not planned but merely 
 fell out so : and since such a combination of circumstances 
 simulating design is unusual, it is not proper to say that the 
 events happened "in the course of Nature." We therefore 
 say it happened by chance. This doctrine of chance has its 
 significance for mediaeval Ethics. In an age when the Pro- 
 testant superstition that worldly success is proof of nearness 
 to God had not yet been invented, the want of correspondence 
 between men's " deserts " and their prosperity was accounted 
 for by the view that the distribution of worldly goods is, as a 
 rule, the work of Fortune or Chance in the Aristotelian sense ; 
 that is, it is due to special coincidences which may look like 
 deliberate design but are not really so. (See the elaborate 
 exposition of this in Dante, Inferno, vii. 67-97.) 
 
 Motion. We have seen that causation, natural or artificial, 
 requires the production in a certain " matter " of a certain 
 " form " under the influence of a certain " agent." What is 
 the character of the process set up by the agent in the matter 
 and culminating in the appearance of the form 1 ? Aristotle 
 answers that it is Motion (kinesis). The effect of the agent 
 on the matter is to set up in it a motion which ends in its 
 assuming a definite form. The important point to be noted 
 here is that Aristotle regards this motion as falling wholly 
 within the matter which is to assume the form. It is not 
 necessary that the agent should itself be in motion, but only 
 that it should induce motion in something else. Thus in all 
 cases of intentional action the ultimate efficient cause is the 
 "idea of the result to be attained," but this idea does not 
 move about. By its presence to the mind it sets something 
 else (the members of the body) moving. This conception of 
 an efficient cause which, not moving itself, by its mere presence 
 induces movement in that to which it is present, is of the 
 highest importance in Aristotle's theology. Of course it follows 
 that since the motion by which the transition from potentiality 
 to actuality is achieved falls wholly within the matter acted 
 upon, Aristotle is not troubled with any of the questions as to 
 the way in which motion can be transferred from one body to 
 another which were so much agitated in the early days of the 
 modern mechanical interpretation of natural processes. Aris- 
 totle's way of conceiving Nature is thoroughly non-mechanical,
 
 FIRST PHILOSOPHY 47 
 
 and approximates to what would now be called the ascription 
 of vital or quasi-vital characteristics to the inorganic. As, in 
 the causality of " art " the mere presence of the " form " to be 
 embodied in a given material to the mind of the craftsman 
 brings about and directs the process of manufacture, so in some 
 analogous fashion the presence of an efficient cause in Nature to 
 that on which it works is thought of as itself constituting the 
 " efficiency " of the cause. As Lotze phrases it, things " take 
 note of" one another's compresence in the universe, or we 
 might say the efficient cause and that on which it exercises 
 its efficiency are en rapport, "Matter" is sensitive to the 
 presence of the " efficient cause," and in response to this 
 sensitivity, puts forth successive determinations, expands its 
 latent tendencies on definite lines. 
 
 The name " motion " has a wider sense for Aristotle than it 
 has for ourselves. He includes under the one common name 
 all the processes by which things come to be what they are or 
 cease to be what they have been. Thus he distinguishes the 
 following varieties of " motion " : generation (the coming of an 
 individual thing into being), with its opposite decay or corruption 
 (the passing of a thing out of being), alteration (change of quality 
 in a thing), augmentation and diminution (change in the magni- 
 tude of a thing), motion through space (of which latter he recog- 
 nises two sub-species, rectilinear transference and rotation in a 
 circular orbit about an axis). It is this last variety, motion 
 through space, which is the most fundamental of all, since its 
 occurrence is involved in that of any of the other types of 
 process mentioned, though Aristotle does not hold the thorough- 
 going mechanical view that the other processes are only 
 apparent, and that, as we should put it, qualitative change is 
 a mere disguise which mechanical motion wears for our senses. 
 
 The Eternity of Motion. Certain very important conse- 
 quences follow from the conception of efficient causation which 
 we have been describing. Aristotle has no sympathy with the 
 " evolutionist " views which had been favoured by some of his 
 predecessors. According to his theory of organic generation, 
 " it takes a man to beget a man " ; where there is a baby, there 
 must have been a father. Biological kinds representing real 
 clefts in Nature, the process of the production of a young 
 generation by an already adult generation must be thought of
 
 48 ARISTOTLE 
 
 as without beginning and without end. There can be no 
 natural " evolution " of animals of one species from individuals 
 of a different kind. Nor does it occur to Aristotle to take into 
 account the possibility of " Creationism," the sudden coming 
 into being of a fully fledged first generation at a stroke. This 
 possibility is excluded by the doctrine that the " matter " of 
 a thing must exist beforehand as an indispensable condition of 
 the production of that thing. Every baby, as we said, must 
 have had a father, but that father must also have been a baby 
 before he was a full-grown man. Hence the perpetuation of 
 unchanging species must be without beginning and without end. 
 And it is implied that all the various processes, within and 
 without the organism, apart from which its life could not 
 be kept up, must be equally without beginning and without 
 end. The " cosmos," or orderly world of natural processes, is 
 strictly " eternal " ; " motion " is everlasting and continuous, 
 or unbroken. Even the great Christian theologians who built 
 upon Aristotle could not absolutely break with him on this 
 point. St. Thomas, though obliged to admit that the world 
 was actually created a few thousand years before^his own time, 
 maintains that this can only be known to be true from revela- 
 tion, philosophically it is equably tenable that the world should 
 have been " created from all eternity." And it is the general 
 doctrine of scholasticism that the expression " creation " only 
 denotes the absolute dependence of the world on God for its 
 being. When we say " God created the world out of nothing," 
 we mean that He did not make it out of pre-existing matter, 
 that it depends for its being on Him only ; the expression is 
 purely negative in its import. 
 
 God. With the doctrine of the eternity of the world and 
 the processes which make up its life we come close to the cul- 
 minating theory of Aristotelian First Philosophy, its doctrine 
 of God, as the eternal, unchanging source of all change, move- 
 ment, and process. All motion is a process within matter by 
 which the forms latent in it are brought into actual manifesta- 
 tion. And the process only takes place in the presence of an 
 adequate efficient cause or source of motion. Hence the eternity 
 of natural processes involves the existence of one or more 
 eternal sources of motion. For, if we do not admit the exist- 
 ence of an unoriginated and ever-present source or sources of
 
 FIRST PHILOSOPHY 49 
 
 motion, our only alternative is to hold that the world-process 
 is due to a series of sources of motion existing successively. 
 But such a view would leave the unity and unbroken continuity 
 of the world-process unaccounted for. It would give us a 
 succession of processes, temporally contiguous, not one unbroken 
 process. Hence we argue from the continuity of motion to its 
 dependence on a source or sources which are permanent and 
 present throughout the whole everlasting world-process. And 
 when we come to the question whether there is only one such 
 ultimate source of movement for the whole universe, or several, 
 Aristotle's answer is that the supreme " Unmoved Mover " is 
 one. One is enough for the purpose, and the law of parcimony 
 forbids us to assume the superfluous. This then is the Aristo- 
 telian conception of God and God's relation to the world. God 
 is the one supreme unchanging being to whose presence the 
 world responds with the whole process of cosmic development, 
 the ultimate educer of the series of "forms" latent in the 
 " matter " of the world into actual manifestation. Standing, 
 as He does, outside the whole process which by His mere 
 presence He initiates in Nature, He is not himself a composite 
 of " form " and " matter," as the products of development are. 
 He is a pure individual " form " or " actuality," with no history 
 of gradual development behind it. Thus He is a purely im- 
 material being, indispensable to the world's existence but trans- 
 cending it and standing outside it. How His presence inspires 
 the world to move Aristotle tries to explain by the metaphor 
 of appetition. Just as the good I desire and conceive, without 
 itself "moving" "moves" my appetition, so God moves the 
 universe by being its good. This directly brings about a uniform 
 unbroken rotation of the whole universe round its axis (in fact, 
 the alternation of day and night). And since this rotation is 
 communicated from the outermost " sphere " of heaven to all 
 the lesser "spheres" between it and the immovable centre, 
 the effects of God's presence are felt universally. At the same 
 time, we must note that though God is the supreme Mover of 
 the Universe, He is not regarded by Aristotle as its Creator, 
 even in the sense in which creation can be reconciled with the 
 eternity of the world. For the effect of God's presence is simply 
 to lead to the development of " form " in an already existing 
 " matter." Without God there could be no " form " or order
 
 50 ARISTOTLE 
 
 in things, not even as much as is implied in the differentiation 
 of matter into the four "elements," yet "primary matter" is 
 no less than God a precondition of all that happens. 
 
 It is characteristic of Aristotle that his God is as far from 
 discharging the functions of a Providence as He is from being 
 a Creator. His " activity " is not, as Plato had made it, that 
 of the great " Shepherd of the sheep." As far as the world is 
 concerned, God's only function is to be there to move its 
 appetition. For the rest, the unbroken activity of this life is 
 directed wholly inward. Aristotle expressly calls it an " activity 
 of immobility." More precisely, he tells us, it is activity of 
 thought, exercised unbrokenly and everlastingly upon the only 
 object adequate to exercise God's contemplation, Himself. 
 His life is one of everlasting se/-contemplation or " thinking 
 of thought itself." Like all unimpeded exercise of activity, it is 
 attended by pleasure, and as the activity is continuous, so the 
 pleasure of it is continuous too. At our best, when we give 
 ourselves up to the pure contemplative activity of scientific 
 thought or aesthetic appreciation, we enter for a while into this 
 divine life and share the happiness of God. But that is a theme 
 for our chapter on the Ethics. 
 
 It is a far cry from this conception of a God untroubled by 
 care for a world to which He is only related as the object of its 
 aspiration to the God who cares even for the fall of the sparrow 
 and of whom it is written, Sic Deus dilexit mundum, but it 
 was the standing task of the philosophical theologians of the 
 Middle Ages to fuse the two conceptions. Plato's God, who, if 
 not quite the Creator, is the " Father and Fashioner " of us all, 
 and keeps providential watch over the world He has fashioned, 
 would have lent Himself better to their purposes, but Plato 
 was held by the mediaeval church to have denied the resurrec- 
 tion of the body. The combination of Aristotle's Theism with 
 the Theism of early Christianity was effected by exquisitely 
 subtle logical devices, but even in St. Thomas one cannot help 
 seeing the seams. 
 
 Nor can one help seeing in Aristotle's own doctrine the 
 usual want of coherence between an initial anti-Platonic bias 
 and a final reversion to the very Platonic positions Aristotle 
 is fond of impugning. We are told at the outset that the 
 Platonic " separate forms " are empty names, and that the
 
 PHYSICS 51 
 
 real individual thing is always a composite of matter and a 
 form which only exists " in matter." We find in the end that 
 the source of the whole process by which " matter " becomes im- 
 bued with " form " is a being which is " pure " form and stands 
 outside the whole development which its presence sets up. 
 And the issue of Aristotle's warning against " poetic metaphors " 
 is the doctrine that God moves the world by being " the object 
 of the world's desire." 
 
 CHAPTER IV 
 
 PHYSICS 
 
 THERE is no part of Aristotle's system which has been more 
 carefully thought out than his Physics ; at the same time it is 
 almost wholly on account of his physical doctrines that his long 
 ascendancy over thought is so much to be regretted. Aristotle's 
 qualifications as a man of science have been much overrated. 
 In one department, that of descriptive natural history, he shows 
 himself a master of minute and careful observation who could 
 obtain unqualified praise from so great a naturalist as Darwin. 
 But in Astronomy and Physics proper his inferiority in mathe- 
 matical thinking and his dislike for mechanical ways of explain- 
 ing facts put him at a great disadvantage, as compared with 
 Plato and Plato's Pythagorean friends. Thus his authority was 
 for centuries one of the chief influences which prevented the de- 
 velopment of Astronomy on right lines. Plato had himself 
 both taught the mobility of the earth and denied correctly that 
 the earth is at the centre of the universe, and the " Coper- 
 uican" hypothesis in Astronomy probably originated in the 
 Academy. Aristotle, however, insists on the central position of 
 the earth, and violently attacks Plato for believing in its motion. 
 It is equally serious that he insists on treating the so-called 
 "four elements" as ultimately unanalysable forms of matter, 
 though Plato had not, only observed that so far from being the 
 ABC (stoicheia or elementa, literally, letters of the alphabet) 
 of Nature they do not deserve to be called even " syllables," 
 but had also definitely put forward the view that it is the 
 geometrical structure of the " corpuscles " of body upon which 
 sensible qualities depend. It is on this doctrine, of course, that
 
 52 ARISTOTLE 
 
 all mathematical physics rests. Aristotle reverts to the older 
 theory that the differences between one " element " and another 
 are qualitative differences of a sensible kind. Even in the 
 biological sciences Aristotle shows an unfortunate proneness to 
 disregard established fact when it conflicts with the theories 
 for which he has a personal liking. Thus, though the import- 
 ance of the brain as the central organ of the sensori-motor 
 system had been discovered in the late sixth or early fifth cen- 
 tury by the physician Alcmaeon of Crotona, and taught by the 
 great Hippocrates in the fifth and by Plato in the fourth 
 century, Aristotle's prejudices in favour of the doctrines [of a 
 different school of biologists led him to revert to the view that 
 it is the heart which is the centre of what we now call the 
 " nervous system." It is mainly on account of these reactionary 
 scientific views that he was attacked in the early seventeenth 
 century by writers like our own Francis Bacon, who found in 
 veneration for Aristotle one of the chief hindrances to the free 
 development of natural science. The same complaints had 
 been made long before by critics belonging to the Platonic 
 Academy. It is a Platonist of the time of Marcus Aurelius 
 who sums up a vigorous attack on the Aristotelian astronomy 
 by the remark that Aristotle never understood that the true 
 task of the physicist is not to prescribe laws to Nature, but to 
 learn from observation of the facts what the laws followed by 
 Nature are. 
 
 In determining the scope of Physics, we have to begin by 
 considering what is the special characteristic of things pro- 
 duced by Nature as contrasted with those produced by "art." 
 The obvious distinction, intimated by the very etymology of 
 the word " Nature " (physis, connected with phyesthai, to 
 grow, to be born, as natura is with nasci), is that " what is by 
 Nature" is born and grows, whereas what is as a result of 
 artifice is made. The "natural" may thus be said to consist 
 of living bodies and of their constituent parts. Hence in- 
 organic matter also is included in "Nature," on the ground 
 that living tissue can be analysed back into compounds of the 
 "elements." Now things which are alive and grow are dis- 
 tinguished from things which are made by "a source of motion 
 and quiescence within themselves " ; all of them exhibit motions, 
 changes of quality, processes of growth and decline which are
 
 PHYSICS 53 
 
 initiated from within. Hence Nature may be defined as the 
 totality of things which have a source of motion internal to 
 themselves and of the constituent parts of such things. Nature 
 then comprises all beings capable of spontaneous change. What- 
 ever either does not change at all, or only changes in conse- 
 quence of external influences, is excluded from Nature. 
 
 Thus the fundamental fact everywhere present in Nature is 
 "change," "process," " motion." Since motion in the literal sense 
 of change of position is involved as a condition of every such 
 process, and such motion requires space through which to move 
 and time to move in, the doctrine of space and time will also 
 form part of Physics. Hence a great part of Aristotle's special 
 lectures on Physics is occupied with discussion of the nature of 
 space and time, and of the continuity which we must ascribe 
 to them if the " continuous motion " on which the unbroken 
 life of the universe depends is to be real Aristotle knows 
 nothing of the modern questions whether space and time are 
 " real " or only " phenomenal," whether they are " objective " 
 or "subjective." Just as he simply assumes that bodies are 
 things that really exist, whether we happen to perceive them 
 or not, so he assumes that the space and time in which they 
 move are real features of a world that does not depend for 
 its existence on our perceiving it. 
 
 His treatment of space is singularly naif. He conceives it 
 as a sort of vessel, into which you can pour different liquids. 
 Just as the same pot may hold first wine and then water, 
 so, if you can say, " there was water here, but now there is 
 air here," this implies the existence of a receptacle which once 
 held the water, but now holds the air. Hence a jug or pot 
 may be called a " place that can be carried about," and space 
 or place may be called "an immovable vessel." Hence the 
 " place " of a thing may be defined as the boundary, or inner 
 surface, of the body which immediately surrounds the thing. 
 It follows from this that there can be no empty space. In 
 the last resort, " absolute space " is the actual surface of the 
 outermost "heaven" which contains everything else in itself 
 but is not contained in any remoter body. Thus all things 
 whatever are " in " this " heaven." But it is not itself " in " 
 anything else. In accord with the standing Greek identifica- 
 tion of determinate character with limitation, Aristotle holds
 
 54 ARISTOTLE 
 
 that this outermost heaven must be at a limited distance from 
 us. Actual space is thus finite in the sense that the volume 
 of the universe could be expressed as a finite number of cubic 
 miles or yards, though, since it must be "continuous," it is 
 infinitely divisible. However often you subdivide a length, an 
 area, or a volume, you will always be dividing it into lesser 
 lengths, &c., which can once more be divided. You will never 
 by division come to "points," i.e. mere positions without 
 magnitude of divisibility. 
 
 The treatment of time is more thoughtful. Time is insepar- 
 ably connected with movement or change. We only perceive that 
 time has elapsed when we perceive that change has occurred. 
 But time is not the same as change. For change is of different 
 and incommensurate kinds, change of place, change of colour, 
 &c. ; but to take up time is common to all these forms of 
 process. And time is not the same as motion. For there are 
 different rates of speed, but the very fact that we can compare 
 these different velocities implies that there are not different 
 velocities of time. Time then is that in terms of which we 
 measure motion, "the number of motion in respect of before 
 and after," i.e. it is that by which we estimate the duration 
 of processes. Thus e.g. when we speak of two minutes, two 
 days, two months as required for a certain process to be com- 
 pleted, we are counting something. This something is time. 
 It does not seem to occur to Aristotle that this definition 
 implies that there are indivisible bits of time, though he quite 
 correctly states the incompatible proposition that time is " made 
 up of successive nows," i.e. moments which have no duration 
 at all, and can no more be counted than the points on a 
 straight line. He recognises of course that the " continuity " 
 of motion implies that of time as well as of space. Since, 
 however, "continuity" in his language means the same thing 
 as indefinite divisibility, it ought not to be possible for him 
 to regard time as " made up of nows " ; time, like linear 
 extension, ought for him to be a "length of" something. 
 
 The Continuous Motion and the " Spheres." The con- 
 tinuous world-process depends upon a continuous movement set 
 up in the universe as a whole by the presence of an everlasting 
 and unchangeable " First Mover," God. From the self-same- 
 ness of God, it follows that this most universal of movements
 
 PHYSICS 55 
 
 must be absolutely uniform. Of what precise kind can such 
 a movement bel As the source of the movement is one, 
 and the object moved is also one viz. the compass of the 
 " heaven," the movement of the primwn mobile or " first 
 moved " the object immediately stimulated to motion by God's 
 presence to it, must be mechanically simple. Now Aristotle, 
 mistakenly, held that there are two forms of movement which 
 are simple and unanalysable, motion of traaslation along a 
 straight line, and motion of rotation round an axis. He is at 
 pains to argue that rectilinear motion, which we easily dis- 
 cover to be that characteristic of bodies near the earth's surface 
 when left to themselves, cannot be the kind of movement 
 which belongs to the " heaven " as a whole. For continuous 
 rectilinear movement in the same direction could not go on 
 for ever on his assumption that there is no space outside the 
 " heaven," which is itself at a finite distance from us. And 
 motion to and fro would not be unbroken, since Aristotle 
 argues that every time a moving body reached the end of its 
 path, and the sense of its movement was reversed, it would 
 be for two consecutive moments in the same place, and there- 
 fore at rest. Reversal of sense would imply a discontinuity. 
 Hence he decides that the primary unbroken movement must 
 be the rotation of the " first moved " that is, the heaven 
 containing the fixed stars round its axis. This is the only 
 movement which could go on for ever at a uniform rate and in 
 the same sense. Starting with the conviction that the earth 
 is at rest in the centre of the universe, he inevitably accounts 
 for the alternation of day and night as the effect of such a 
 revolution of the whole universe round an axis passing 
 through the centre of the earth. The universe is thus thought 
 of as bounded by a spherical surface, on the concave side of 
 which are the fixed stars, which are therefore one and all at 
 the same distance from us. This sphere, under the immediate 
 influence of God, revolves on its axis once in twenty-four hours, 
 and this period of revolution is absolutely uniform. Next the 
 apparently irregular paths of the " planets " known to Aristotle 
 (i.e. the moon, Mercury, Venus, the sun, Mars, Jupiter, 
 Saturn) are resolved into combinations of similar uniform 
 rotations, each planet having as many " spheres " assigned to 
 it as are requisite for the analysis of its apparent path into
 
 56 ARISTOTLE 
 
 perfectly circular elementary motions. Altogether Aristotle 
 holds that fifty-four such rotating spheres are required over 
 and above the "first moved" itself, whose rotation is, of 
 course, communicated to all the lesser "spheres" included 
 within it. As in the case of the "first moved," the uniform 
 unceasing rotation of each "sphere" is explained by the 
 influence on it of an unchanging immaterial " form," which 
 is to its own " sphere " what God is to the universe as a 
 whole. In the Aristotelian ism of the mediaeval church these 
 pure forms or intelligences which originate the movements of 
 the various planetary spheres are naturally identified with 
 angels. It is e.g. to the angelic intelligences which "move" 
 the heaven of Venus, which comes third in order counting out- 
 ward from the earth, that Dante addresses his famous Canzone, 
 Voi ch' intendendo il terzo del movete. The mediaeval astronomy, 
 however, differs in two important respects from that of Aristotle 
 himself. (1) The number of "spheres" is different. Increas- 
 ing knowledge of the complexity of the paths of the planets 
 showed that if their paths are to be analysed into combina- 
 tions of circular motions, fifty-four such rotations must be an 
 altogether inadequate number. Aristotle's method of analysis 
 of the heavenly movements was therefore combined with either 
 or both of two others originated by pure astronomers who sat 
 loose to metaphysics. One of these methods was to account 
 for a planet's path by the introduction of epicycles. The 
 planet was thought of not as fixed at a given point on its 
 principal sphere, but as situated on the circumference of a 
 lesser sphere which has its centre at a fixed point of the 
 principal sphere and rotates around an axis passing through 
 this centre. If need were, this type of hypothesis could be 
 further complicated by imagining any number of such epicycles 
 within epicycles. The other method was the employment of 
 " eccentrics," i.e. circular movements which are described not 
 about the common centre of the earth and the universe, but 
 about some point in its neighbourhood. By combinations of 
 epicycles and eccentrics the mediaeval astronomers contrived 
 to reduce the number of principal spheres to one for each 
 planet, the arrangement we find in Dante. (2) Also real or 
 supposed astronomical perturbations unknown to Aristotle 
 led some mediaeval theorists to follow the scheme devised by
 
 PHYSICS 57 
 
 Alphonso the Wise of Castille, in which further spheres are 
 inserted between that of Saturn, the outermost planet, and 
 the " first moved." In Dante, we have, excluding the " em- 
 pyrean " or immovable heaven where God and the blessed are, 
 nine " spheres," one for each of the planets, one for the fixed 
 stars, and one for the " first moved," which is now distin- 
 guished from the heaven of the stars. In Milton, who adopts 
 the "Alphonsine" scheme, we have further a sphere called 
 the "second movable" or "crystalline" introduced between 
 the heaven of the fixed stars and the " first moved," to account 
 for the imaginary phenomenon of " trepidation." l In reading 
 Dante, Shakespeare, and Milton, we have always to remember 
 that none of these reproduces the Aristotelian doctrine of the 
 " spheres " accurately ; their astronomy is an amalgam of Aris- 
 totle, Ptolemy, and Hipparchus. 
 
 So far, the doctrine of the fifty-five " spheres " might be no 
 more than a legitimate mathematical fiction, a convenient device 
 for analysing the complicated apparent movements of the heavenly 
 bodies into circular components. This was originally the part 
 played by " spheres " in ancient astronomical theory, and it is 
 worth while to be quite clear about the fact, as there is a mis- 
 taken impression widely current to-day that Aristotle's astronomy 
 is typical of Greek views in general. The truth is that it is 
 peculiar to himself. The origin of the theory was Academic. 
 Plato proposed to the Academy as a subject of inquiry, to 
 devise such a mathematical analysis of astronomical motions as 
 will best " save the appearances," i.e. will most simply account 
 for the apparent paths of the planets. The analysis of these 
 paths into resultants of several rotations was offered as a solution 
 by the astronomer Eudoxus of Cnidus. So far, the " spheres," 
 then, were a mere mathematical hypothesis. What Aristotle 
 did, and it is perhaps the most retrograde step ever taken in 
 the history of a science, was to convert the mathematical 
 hypothesis into physical fact. The " spheres " become with 
 him real bodies, and as none of the bodies we are familiar with 
 exhibit any tendency to rotate in circles when left to themselves, 
 
 1 Paradite Lost, iii. 481. 
 
 "They pass the planets seven, and pass the fixed, 
 And that crystalline sphere whose balance weighs 
 The trepidation talked, and that first moved."
 
 58 ARISTOTLE 
 
 Aristotle was forced to introduce into Physics the disastrous 
 theory, which it was a great part of Galileo's life-work to 
 destroy, that the stuff of which the spheres are made is a 
 "fifth body," different from the "elements" of which the 
 bodies among which we live are made. Hence he makes an 
 absolute distinction between two kinds of matter, " celestial 
 matter," the "fifth body," and "terrestrial" or "elementary" 
 matter. The fundamental difference is that " terrestrial " or 
 " elementary " matter, left to itself, follows a rectilinear path, 
 " celestial " matter rotates, but it is further inferred from the 
 supposed absolute uniformity of the celestial movements that 
 "celestial matter" is simple, uncompouuded, incapable of 
 change, and consequently that no new state of things can ever 
 arise in the heavens. The spheres and planets have always 
 been and will always be exactly as they are at the present 
 moment. Mutability is confined to the region of " terrestrial " 
 or " elementary " matter, which only extends as far as the orbit 
 of the moon, the " lowest of the celestial bodies," because it is 
 only " terrestrial " things which are, as we should say, chemical 
 compounds. This is the doctrine which Galileo has in mind 
 when he dwells on such newly- discovered astronomical facts as 
 the existence of sun-spots and variable stars, and the signs of 
 irregularity presented by the moon's surface. The distinction 
 is peculiar to Aristotle. No one before him had ever thought 
 of supposing the heavenly bodies to be made of any materials 
 other than those of which " bodies terrestrial " are made. In 
 the Academic attack on Aristotle's science of which we have 
 already spoken the two points singled out for reprobation are 
 (1) his rejection of the principle that all moving bodies, left to 
 themselves, follow a rectilinear path, and (2) his denial that 
 the heavenly bodies are made of the same " elements " as every- 
 thing else. (It may just be mentioned in passing that our 
 word quintessence gets its sense from the supposed special 
 "nobility" of the incorruptible "fifth body.") 
 
 Terrestrial Bodies. As we have seen already, Aristotle was 
 out of sympathy with the tendency to regard the sensible 
 differences between bodies as consequences of more ultimate 
 differences in the geometrical structure of their particles. Hence 
 his whole attitude towards the problems of that branch of 
 natural science which we call physics is quite unlike any view
 
 PHYSICS 59 
 
 to which we are accustomed. He reverts from the mathematical 
 lines of thought current in Plato's Academy to the type of view 
 more natural to the " plain man," and, like the earliest sixth- 
 century men of science, regards the qualitative differences which 
 our senses apprehend as fundamental. Among these, particular 
 stress is laid on the difference in sensible temperature (the hot 
 the cold), in saturation (the dry the moist), and in density 
 (the dense the rare). If we consider the first two of these 
 oppositions, we can make four binary combinations of the 
 elementary "opposite" characters, viz. hofl^dnd dry, hot and 
 moist, cold and moist, cold and dry. These combinations are 
 regarded as corresponding respectively to the sensible character- 
 istics of the four bodies which Empedocles, the father of Greek 
 chemistry, had treated as the ultimate components of everything. 
 Fire is hot and dry, air hot and moist, water moist and cold, 
 earth cold and dry. This reflection shows us why Aristotle 
 held that the most rudimentary form in which " matter " ever 
 actually exists is that of one of these "elements." Each of 
 them has one quality in common with another, and it is in 
 virtue of this that a portion of one element can be assimilated 
 by and transmuted into another, a process which seems to the 
 untutored eye to be constantly recurring in Nature. We also 
 observe that the order in which the " elements " appear, when 
 so arranged as to form a series in which each term has one 
 quality in common with each of its neighbours, is also that of 
 their increasing density. This would help to make the con- 
 ception of their transmutability all the more natural, as it 
 suggests that the process may be effected by steady condensation. 
 We must remember carefully that for Aristotle, who denies the 
 possibility of a vacuum, as for the mediaeval alchemists, con- 
 densation does not mean a mere diminution of the distances 
 between corpuscles which remain unchanged in character, but is 
 a process of real qualitative change in the body which undergoes 
 it. Incidentally we may remark that all changes of quality 
 are regarded by Aristotle as stages in a continuous " movement " 
 from one extreme of a scale to another. For example, colours, 
 with him as with Goethe, form a series of which the " opposites " 
 white and black are the end-points. Every other colour is a 
 combination of white and black according to a definite pro- 
 portion.
 
 60 ARISTOTLE 
 
 The Aristotelian doctrine of weight was one of the chief 
 obstacles which seventeenth-century science had to contend 
 with in establishing correct notions in dynamics. It is a 
 curious feature of Greek science before Aristotle that, though 
 the facts connected with gravity were well known, no one intro- 
 duced the notion of weight to account for them. The differ- 
 ence between heavy bodies and light bodies had been previously 
 treated as secondary for science. Plato's treatment of the 
 matter is typical of the best fourth-century science. We must 
 not try to explain why the heavier bodies tend to move towards 
 the earth's surface by saying that they have a " downward " 
 motion ; their motion is not downward but " towards the 
 centre" (the earth, though not fixed at the centre of the 
 universe, being nearer to it than the rest of the solar and 
 sidereal system). Plato then explains the tendency in virtue 
 of which the heavier bodies move towards the " centre " as an 
 attraction of like for like. The universal tendency is for smaller 
 masses of "earth," "water," "air," "fire" to be attracted 
 towards the great aggregations of the same materials. This 
 is far from being a satisfactory theory in the light of facts 
 which were not yet known to Plato, but it is on the right 
 lines. It starts from the conception of the facts of gravity as 
 due to an "attractive force" of some kind, and it has the 
 great merit of bringing the "sinking" of stones and the 
 " rising " of vapours under the same explanation. 
 
 Aristotle, though retaining the central idea that a body 
 tends to move towards the region where the great cosmic mass 
 of the same kind is congregated, introduced the entirely incom- 
 patible notion of an absolute distinction of " up " and " down." 
 He identified the centre of the universe with that of the earth, 
 and looked on motion to this centre as "downward." This 
 led him to make a distinction between " heavy " bodies, which 
 naturally tend to move "down," and "light" bodies, which 
 tend to move "up" away from the centre. The doctrine 
 works out thus. The heaviest elements tend to be massed 
 together nearest the centre, the lightest to be furthest from it. 
 Each element thus has its " proper place," that of water being 
 immediately above earth, that of air next, and that of fire 
 furthest from the centre, and nearest to the regions occupied 
 by "celestial matter." (Readers of Dante will recollect the
 
 PHYSICS 61 
 
 ascent from the Earthly Paradise through the " sphere of fire " 
 with which the Paradiso opens.) 
 
 In its own " proper region " no body is heavy or light ; as 
 we should say any fluid loses its weight when immersed in 
 itself. When a portion of an element is out of its own region 
 and surrounded by the great cosmic aggregate of another 
 element, either of two cases may occur. The body which is 
 " out of its element " may be below its proper place, in which 
 case it is " light " and tends to move perpendicularly upwards 
 to its place, or it may be above its proper place, and then it 
 is " heavy " and tends to move perpendicularly " down " until 
 it reaches its place. It was this supposed real distinction 
 between motion " up " and motion " down " which made it so 
 hard for the contemporaries of Galileo to understand that an 
 inflated bladder rises for the same reason that a stone sinks. 
 
 Biology. Of Aristotle's biology reasons of space forbid us to 
 say much here. But a remark or two may be made about his 
 theory of reproduction, since it is constantly referred to in much 
 modern literature and has also played its part in theology. 
 An interesting point is the distinction between " perfect " and 
 " imperfect " animals. " Perfect " animals are those which 
 can only be reproduced sexually. Aristotle held, however, that 
 there are some creatures, even among vertebrates, which may 
 be produced by the vivifying effect of solar heat on decompos- 
 ing matter, without any parents at all. Thus malobservation 
 of the facts of putrefaction led to the belief that flies and 
 worms are engendered by heat from decaying bodies, and it 
 was even thought that frogs and mice are produced in the 
 same way from river-slime. In this process, the so-called 
 "aequivocal generation," solar heat was conceived as the 
 operative efficient cause which leads to the realisation of an 
 organic " form " in the decaying matter. 
 
 In sexual reproduction Aristotle regards the male parent 
 as the agent or efficient cause which contributes the element of 
 form and organisation to the offspring. The female parent 
 supplies only the raw material of the new creature, but she 
 supplies the whole of this. No material is supplied by the 
 male parent to the body of the offspring, a theory which St. 
 Thomas found useful in defending the dogma of the Virgin 
 Birth.
 
 62 ARISTOTLE 
 
 Psychology. Since the mind grows and develops, it comes 
 under the class of things which have a "source of motion 
 internal to themselves," and psychology is therefore, for 
 Aristotle, a branch of Physics. To understand his treatment 
 of psychological questions we need bear two things in mind. 
 (1) Psyche or "soul" means in Greek more than "conscious- 
 ness " does to us. Consciousness is a relatively late and highly 
 developed manifestation of the principle which the Greeks 
 call "soul." That principle shows itself not merely in con- 
 sciousness but in the whole process of nutrition and growth 
 and the adaptation of motor response to an external situation. 
 Thus consciousness is a more secondary feature of the " soul " 
 in Greek philosophy than in most modern thought, which has 
 never ceased to be affected by Descartes' selection of " thought " 
 as the special characteristic of psychical life. In common 
 language the word psyche is constantly used where we should 
 say "life" rather than "soul," and in Greek philosophy a 
 work " on the Psyche " means what we should call one on " the 
 principle of life." 
 
 (2) It is a consequence of this way of thinking of the 
 " soul " that the process of bodily and mental development is 
 regarded by Aristotle as one single continuous process. The 
 growth of a man's intellect and character by which he becomes 
 a thinker and a citizen is a continuation of the process by which 
 his body is conceived and born and passes into physical man- 
 hood. This comes out in the words of the definition of the 
 soul. " The soul is the first entelechy (or actual realisation) of 
 a natural organic body." What this means is that the soul stands 
 to the living body as all form realised in matter does to the 
 matter of which it is the form, or that the soul is the " form " 
 of the body. What the " organic body " is to the embryo out 
 of which it has grown, that soul is to the body itself. As the 
 embryo grows into the actual living body, so the living body 
 grows into a body exhibiting the actual directing presence of 
 mind. Aristotle illustrates the relation by the remark that if 
 the whole body was one vast eye, seeing would be its soul. As 
 the eye is a tool for seeing with, but a living tool which is 
 part of ourselves, so the body is a like tool or instrument for 
 living with. Hence we may say of the soul that it is the 
 " end " of the body, the activity to which the body is instru-
 
 PHYSICS 63 
 
 mental, as seeing is the "end" to which the eye is instru- 
 mental. But we must note that the soul is called only the 
 " first " or initial " entelechy " of the body. The reason is 
 that the mere presence of the soul does not guarantee the full 
 living of the life to which our body is but the instrument. If 
 we are to live in the fullest sense of the word, we must not 
 merely " have " a soul ; we " have " it even in sleep, in ignor- 
 ance, in folly. The soul itself needs further to be educated 
 and trained in intelligence and character, and to exercise its 
 intelligence and character efficiently on the problems of thought 
 and life. The mere " presence " of soul is only a first step in 
 the progress towards fullness of life. This is why Aristotle 
 calls the soul the first entelechy of the living body. The full 
 and final entelechy is the life of intelligence and character 
 actively functioning. 
 
 From this conception of the soul's relation to the body we 
 see that Aristotle's "doctrine of body and mind" does not 
 readily fall into line with any of the typical theories of our 
 time. He neither thinks of the soul as a thing acting on the 
 body and acted on by it, nor yet as a series of " states of mind " 
 concomitant with certain " states of body." From his point of 
 view to ask whether soul and body interact, or whether they 
 exhibit " parallelism," would be much the same thing as to 
 ask whether life interacts with the body, or whether there 
 is a " parallelism " between vital processes and bodily pro- 
 cesses. We must not ask at all how the body and soul are 
 united. They are one thing, as the matter and the form of a 
 copper globe are one. Thus they are in actual fact inseparable. 
 The soul is the soul of its body and the body the body of its soul. 
 We can only distinguish them by logical analysis, as we can 
 distinguish the copper from the sphericity in the copper globe. 
 
 Grades of Psychical Life. If we consider the order of de 
 velopment, we find that some vital activities make their appear- 
 ance earlier than others, and that it is a universal law that the 
 more highly developed activities always have the less highly 
 developed as their basis and precondition, though the less 
 highly developed may exist apart from the more highly 
 developed. So we may arrange vital activities in general in an 
 ontogenetic order, the order in which they make their appear- 
 ance in the individual's development. Aristotle reckons three
 
 64 ARISTOTLE 
 
 such stages, the " nutritive," the "sensitive," and the "in- 
 telligent." The lowest form in which life shows itself at all, 
 the level of minimum distinction between the living and the 
 lifeless, is the power to take in nutriment, assimilate it, and 
 grow. In vegetables the development is arrested at this point. 
 With the animals we reach the next highest level, that of 
 " sensitive " life. For all animals have at least the sense of 
 touch. Thus they all show sense-perception, and it is a con- 
 sequence of this that they exhibit " appetition," the simplest 
 form of conation, and the rudiments of feeling and " temper." 
 For what has sensations can also feel pleasure and pain, and 
 what can feel pleasure and pain can desire, since desire is only 
 appetition of what is pleasant. Thus in the animals we have 
 the beginnings of cognition, conation, and affective and emo- 
 tional life in general. And Aristotle adds that locomotion 
 makes its appearance at this level ; animals do not, like plants, 
 have to trust to their supply of nutriment coming to them ; 
 they can go to it. 
 
 The third level, that of "intelligence," i.e. the power to 
 compare, calculate, and reflect, and to order one's life by con- 
 scious rule, is exhibited by man. What distinguishes life at 
 this level from mere " sensitive " life is, on the intellectual side, 
 the ability to cognise universal truths, on the conative, the 
 power to live by rule instead of being swayed by momentary 
 " appetition." The former gives us the possibility of science, 
 the latter of moral excellence. 1 
 
 Sensation. Life manifests itself at the animal level on the 
 cognitive side as sense-perception, on the conative as appetition 
 or desire, on the affective as feeling of pleasure or pain, and in 
 such simple emotional moods as " temper," resentment, longing. 
 Aristotle gives sensation a logical priority over the conative 
 and emotional expression of "animal" life. To experience 
 appetitiou or anger or desire you must have an object which 
 you crave for or desire or are angry with, and it is only when 
 you have reached the level of presentations through the senses 
 that you can be said to have an object. Appetition or 
 " temper " is as real a fact as perception, but you cannot crave 
 for or feel angry with a thing you do not apprehend. 
 
 1 Cf. Dante's " FattI non foste a viver come bruti, 
 Ma per seguir virtute e conoscenza."
 
 PHYSICS 65 
 
 Aristotle's definition of sense perception is that it is a "capacity 
 for discerning " or distinguishing between " the sensible qualities 
 of things." His conception of the process by which the dis- 
 cernment or distinguishing is effected is not altogether happy. 
 In sense-perception the soul " takes into itself the form of the 
 thing perceived without its matter, as sealing-wax receives the 
 shape of an iron seal-ring without the iron." To understand 
 this, we have to remember that for Aristotle the sensible 
 qualities of the external world, colour, tones, tastes, and the 
 rest, are not effects of mechanical stimulation of our sense- 
 organs, but real qualities of bodies. The hardness of iron, the 
 redness of a piece of red wax are all primarily " in " the iron 
 or the wax. They are "forms," or determinations by definite 
 law, of the " matter " of the iron or the wax. This will become 
 clearer if we consider a definite example, the red colour of the 
 wax. In the wax the red colour is a definite combination of 
 the colour-opposites white and black according to a fixed ratio. 
 Now Aristotle's view of the process of sense-perception is that 
 when I become aware of the red colour the same proportion of 
 white to black which makes the wax red is reproduced in my 
 organ of vision ; my eye, while I am seeing the red, " assimi- 
 lated " to the wax, is itself for the time actually " reddened." 
 But it does not become wax because the red thing I am looking 
 at is a piece of red wax. The eye remains a thing composed 
 of living tissues. This is what is meant by saying that in 
 seeing the colours of things the eye receives " forms " without 
 the "matter" of the things in which those forms are exhibited. 
 Thus the process of sense-perception is one in which the organ 
 of sense is temporarily assimilated to the thing apprehended in 
 respect of the particular quality cognised by that organ, but in 
 respect of no other. According to Aristotle this process of 
 " assimilation " always requires the presence of a "medium." 
 If an object is in immediate contact with the eye we cannot 
 see its colour ; if it is too near the ear, we do not discern the 
 note it gives out. Even in the case of touch and taste there 
 is no immediate contact between the object perceived and the 
 true organ of perception. For in touch the " flesh " is not the 
 organ of apprehension but an integument surrounding it and 
 capable of acting as an intermediary between it and things. 
 Thus perception is always accomplished by a " motion " set up
 
 66 ARISTOTLE 
 
 in the " medium " by the external object, and by the medium 
 in our sense-organs. Aristotle thus contrives to bring correct 
 apprehension by sense of the qualities of things under the 
 formula of the " right mean " or " right proportion," which is 
 better known from the use made of it in the philosopher's theory 
 of conduct. The colour of a surface, the pitch of the note given 
 out by a vibrating string, &c., depend on, and vary with, 
 certain forms or ratios " in " the surface or the vibrating string ; 
 our correct apprehension of the qualities depends on the re- 
 production of the same ratios in our sense-organs, the establish- 
 ment of the " right proportion " in us. That this " right 
 proportion" may be reproduced in our own sense-organs it is 
 necessary (1) that the medium should have none of the sensible 
 qualities for the apprehension whereof it serves as medium, 
 e.g. the medium in colour-perception must be colourless. If 
 it had a colour of its own, the " motion " set up by the coloured 
 bodies we apprehend would not be transmitted undistorted to 
 our organs ; we should see everything through a coloured haze. 
 It is necessary for the same reason (2) that the percipient 
 organ itself, when in a state of quiescence, should possess none 
 of the qualities which can be induced in it by stimulation. 
 The upshot of the whole theory is that the sense-organ is 
 " potentially " what the sense-quality it apprehends is actually. 
 Actual perceiving is just that special transition from the 
 potential to the actual which results in making the organ for 
 the time being actually of the same quality as the object. 
 
 The Common Sensibles and the Common Sense-organ. 
 Every sense has a range of qualities connected with it as its 
 special objects. Colours can only be perceived by the eye, 
 sounds by the ear, and so forth. But there are certain 
 characters of perceived things which we appear to apprehend 
 by more than one sense. Thus we seem to perceive size and 
 shape either by touch or by sight, and number by hearing as 
 well, since we can count e.g. the strokes of an unseen bell. 
 Hence Aristotle distinguishes between the " special sensible 
 qualities " such as colour and pitch, and what he calls the 
 "common sensibles," the character of things which can be per- 
 ceived by more than one organ. These are enumerated as size, 
 form or shape, number, motion (and its opposite rest), being. 
 (The addition of this last is, of course, meant to account for
 
 PHYSICS 67 
 
 our conviction that any perceived colour, taste, or other quality 
 is a reality and not a delusion.) The list corresponds very 
 closely with one given by Plato of the " things which the mind 
 perceives by herself without the help of any organ" i.e. of the 
 leading determinations of sensible things which are due not to 
 sense but to understanding. It was an unfortunate innovation 
 to regard the discernment of number or movement, which 
 obviously demand intellectual processes such as counting and 
 comparison, as performed immediately by " sense," and to 
 assign the apprehension of number, movement, figure to a 
 central "organ." This organ he finds in the heart. The 
 theory is that when the "special organs" of the senses are 
 stimulated, they in turn communicate movements to the blood 
 and " animal spirits " (i.e. the vapours supposed to be produced 
 from the blood by animal heat). These movements are propagated 
 inwards to the heart, where they all meet. This is supposed to 
 account for the important fact that, though our sensations are so 
 many and diverse, we are conscious of our own unity as the 
 subjects apprehending all this variety. The unity of the per- 
 ceiving subject is thus made to depend on the unity of the 
 ultimate " organ of sensation," the heart. Further, when once 
 a type of motion has been set up in any sense-organ at the 
 periphery of the body it will be propagated inward to the " com- 
 mon sensorium " in the heart. The motions set up by stimulation, 
 e.g. of the eye and of the skin, are partly different, partly the same 
 (viz. in so far as they are determined by the number, shape, 
 size, movement of the external stimuli). Hence in the heart 
 itself the stimulation on which perception of number or size 
 depends is one and the same whether it has been transmitted 
 from the eye or from the skin. Awareness of lapse of time is 
 also regarded as a function of the " common sense-organ," since 
 it is the " common sensory " which perceives motion, and lapse 
 of time is apprehended only in the apprehension of motion. 
 Thus, in respect of the inclusion of geometrical form and lapse 
 of time among the "common sensibles," there is a certain 
 resemblance between Aristotle's doctrine and Kant's theory 
 that recognition of spatial and temporal order is a function not 
 of understanding but of " pure " sense. It is further held that 
 to be aware that one is perceiving (self-consciousness) and to 
 discriminate between the different classes of " special " sense-
 
 68 ARISTOTLE 
 
 perception must also be functions of the " common sense-organ." 
 Thus Aristotle makes the mistake of treating the most funda- 
 mental acts of intelligent reflection as precisely on a par, from 
 the point of view of the theory of knowledge, with awareness 
 of colour or sound. 
 
 A more legitimate function assigned to the "common 
 sensorium " in the heart is that " fantasy," the formation of 
 mental imagery, depends on its activity. The simplest kind of 
 "image," the pure memory-image left behind after the object 
 directly arousing perception has ceased to stimulate, is due to 
 the persistence of the movements set up in the heart after the 
 sensory process in the peripheral organ is over. Since Aristotle 
 denies the possibility of thinking without the aid of memory- 
 images, this function of the " common sensorium " is the in- 
 dispensable basis of mental recall, anticipation, and thought. 
 Neither "experience," i.e. a general conviction which results 
 from the frequent repetition of similar perceptions, nor thought 
 can arise in any animal in which sense-stimulation does not 
 leave such " traces " behind it. Similarly " free imagery," the 
 existence of trains of imagination not tied down to the repro- 
 duction of an actual order of sensations, is accounted for by the 
 consideration that " chance coincidence " may lead to the stimula- 
 tion of the heart in the same way in which it might have been 
 stimulated by actual sensation-processes. Sleeping and waking 
 and the experiences of dream-life are likewise due to changes 
 in the functioning of the " common sense-organ," brought about 
 partly by fatigue in the superficial sense-organs, partly by 
 qualitative changes in the blood and " animal spirits " caused 
 by the processes of nutrition and digestion. Probably Aristotle's 
 best scientific work in psychology is contained in the series of 
 small essays in which this theory of memory and its imagery 
 is worked out. (Aristotle's language about the "common 
 sensibles " is, of course, the source of our expression " common 
 sense," which, however, has an entirely different meaning. The 
 shifting of sense has apparently been effected through Cicero's 
 employment of the phrase sensus communis to mean tactful 
 sympathy, the feeling of fellowship with our kind on which the 
 Stoic philosophers laid so much stress.) 
 
 Thought. Though thinking is impossible except by the 
 use of imagery, to think is not merely to possess trains of
 
 PHYSICS 69 
 
 imagery, or even to be aware of possessing them. Thinking 
 means understanding the meaning of such mental imagery and 
 arriving through the understanding at knowledge of the structure 
 of the real world. How this process of interpreting mental 
 imagery and reaching valid truth is achieved with greater and 
 greater success until it culminates in the apprehension of the 
 supreme principles of philosophy we have seen in dealing with 
 the Aristotelian theory of knowledge. From the point of view 
 of the " physicist " who is concerned with thinking simply as a 
 type of natural process, the relation of " understanding " to the 
 mental imagery just described is analogous to that of sensation 
 to sensible qualities. The objects which thinking apprehends 
 are the universal types of relation by which the world of things 
 is pervaded. The process of thinking is one in which this 
 system of universal relations is reproduced " by way of idea " in 
 the mind of the thinker. The " understanding " thus stands 
 to its objects as matter to form. The process of getting actu- 
 ally to understand the world is one in which our " thought " 
 or "understanding" steadily receives completer determination 
 and " form " from its contemplation of reality. In this sense, 
 the process is one in which the understanding may be said to 
 be passive in knowledge. It is passive because it is the subject 
 which, at every fresh stage in the progress to knowledge, is 
 being quite literally "informed" by the action of the real world 
 through the sensation and imagery. Hence Aristotle says that, 
 in order that the understanding may be correctly " informed " 
 by its contact with its objects, it must, before the process 
 begins, have no determinate character of its own. It must be 
 simply a capacity for apprehending the types of interconnection. 
 " What is called the intelligence I mean that with which the 
 soul thinks and understands is not an actual thing until it 
 thinks." (This is meant to exclude any doctrine which credits 
 the "understanding" with either furniture of its own such as 
 " innate ideas," or a specific structure of its own. If the re- 
 sults of our thinking arose partly from the sft-ucture of the 
 world of objects and partly from inherent laws of the "structure 
 of mind," our thought at its best would not reproduce the 
 universal " forms " or " types " of interconnection as they really 
 are, but would distort them, as the shapes of things are dis- 
 torted when we see them through a lens of high refractive
 
 70 ARISTOTLE 
 
 index.) Thus, though Aristotle differs from the modern em- 
 piricists in holding that " universals " really exist " in " things, 
 and are the links of connection between them, he agrees with 
 the empiricist that knowledge is not the resultant of a combina- 
 tion of "facts" on the one side and "fundamental laws of the 
 mind's working " on the other. At the outset the " under- 
 standing " has no structure ; it develops a structure for itself in 
 the same process, and to the same degree, in which it appre- 
 hends the " facts." Hence the " understanding " only is real 
 in the actual process of understanding its objects, and again in 
 a sense the understanding and the things it understands are 
 one. Only we must qualify this last statement by saying that 
 it is only " potentially " that the understanding is the forms 
 which it apprehends. Aristotle does not mean by this that such 
 things as horses and oxen are thoughts or " ideas." By the 
 things with which " understanding " is said to be one he means 
 the " forms " which we apprehend when we actually understand 
 the world or any part of it, the truths of science. His point 
 then is that the actual thinking of these truths and the truths 
 themselves do not exist apart from one another. "Science" 
 does not mean certain things written down in a book ; it means 
 a mind engaged in thinking and knowing things, and of the 
 mind itself, considered out of its relation to the actual life of 
 thinking the truths of science, we can say no more than that it 
 is a name for the fact that we are capable of achieving such 
 thought. 
 
 The Active Intelligence. So far Aristotle's account 
 of thought has been plain sailing. Thought has been con- 
 sidered as the final and highest development of the vital 
 functions of the organism, and hence as something insepar- 
 able from the lower functions of nutrition and sensitive life. 
 The existence of a thought which is not a function of a living 
 body, and which is not " passive," has been absolutely excluded. 
 But at this point we are suddenly met by the most startling 
 of all the inconsistencies between the naturalistic and the 
 " spiritualist " strains in Aristotle's philosophy. In a few 
 broken lines he tells us that there is another sense of the word 
 " thought " in which " thought " actually creates the truths it 
 understands, just as light may be said to make the colours 
 which we see by its aid. "And this intelligence," he adds,
 
 PHYSICS 71 
 
 " is separable from matter, and impassive and unmixed, being 
 in its essential nature an activity. ... It has no intermission in 
 its thinking. It is only in separation from matter that it is 
 fully itself, and it alone is immortal and everlasting . . . while 
 the passive intelligence is perishable and does not think at all, 
 apart from this." The meaning of this is not made clear by 
 Aristotle himself, and the interpretation was disputed even 
 among the philosopher's personal disciples. 
 
 One important attempt to clear up the difficulty is that 
 made by Alexander of Aphrodisias, the greatest of the com- 
 mentators on Aristotle, in the second century A.D. Alexander 
 said, as Aristotle has not done, that the " active intelligence " 
 is numerically the same in all men, and is identical with God. 
 Thus, all that is specifically human in each of us is the 
 "passive intelligence" or capacity for being enlightened by 
 God's activity upon us. The advantage of the view is, that 
 it removes the " active intelligence " altogether from the pur- 
 view of psychology, which then becomes a purely naturalistic 
 science. The great Arabian Aristotelian, Averroes (Ibn 
 Roschd) of Cordova, in the twelfth century, went still further 
 in the direction of naturalism. Since the "active" and 
 "passive" intelligence can only be separated by a logical 
 abstraction, he inferred that men, speaking strictly, do not 
 think at all ; there is only one and the same individual intelli- 
 gence in the universe, and all that we call our thinking is 
 really not ours but God's. The great Christian scholastics 
 of the following century in general read Aristotle through 
 the eyes of Averroes, " the Commentator," as St. Thomas calls 
 him, "Averrois che il gran commento feo," as Dante says. 
 But their tneology compelled them to disavow his doctrine 
 of the "active intelligence," against which they could also 
 bring, as St. Thomas does, the telling argument that Aristotle 
 could never have meant to say that there really is no such 
 thing as human intelligence. Hence arose a third interpreta- 
 tion, the Thomist, according to which the " active intelligence " 
 is neither God nor the same for all men, but is the highest and 
 most rational "part" of the individual human soul, which 
 has no bodily " organ,"
 
 72 ARISTOTLE 
 
 CHAPTER V 
 
 PRACTICAL PHILOSOPHY 
 
 HITHERTO we have been concerned with the speculative 
 branches of knowledge, we have now to turn to practice. 
 Practice, too, is an activity of thought, but an activity which 
 is never satisfied by the process of thinking itself. In prac- 
 tice our thinking is always directed towards the production of 
 some result other than true thought itself. As in engineering 
 it is not enough to find a solution of the problem how to 
 build a bridge over a given river capable of sustaining a given 
 strain, so in directing our thought on the problems of human 
 conduct and the organisation of society we aim at something 
 more than the understanding of human life. In the one case 
 what we aim at is the construction of the bridge ; in the other 
 it is the production of goodness in ourselves and our fellow- 
 men, and the establishment of right social relations in the 
 state. Aristotle is careful to insist on this point throughout 
 his whole treatment of moral and social problems. The princi- 
 pal object of his lectures on conduct is not to tell his hearers 
 what goodness is, but to make them good, and similarly it is 
 quite plain that Politics was intended as a text-book for legis- 
 lators. In close connection with this practical object stands 
 his theory of the kind of truth which must be looked for 
 in ethics and politics. He warns us against expecting precepts 
 which have the exact and universal rigidity of the truths of 
 speculative science. Practical science has to do with the 
 affairs of men's lives, matters which are highly complex and 
 variable, in a word, with "what may be otherwise." Hence 
 we must be content if we can lay down precepts which hold 
 good in the main, just as in medicine we do not expect to find 
 directions which will effect a cure in all cases, but are content 
 with general directions which require to be adapted to special 
 cases by the experience and judgment of the practitioner. The 
 object of practical science then is to formulate rules which will 
 guide us in obtaining our various ends. Now when we con- 
 sider these ends we see at once that some are subordinate
 
 PRACTICAL PHILOSOPHY 73 
 
 to others. The manufacture of small-arms may be the end 
 at which their maker aims, but it is to the military man 
 a mere means to his end, which is the effective use of them. 
 Successful use of arms is again the end of the professional soldier, 
 but it is a mere means among others to the statesman. Fur- 
 ther, it is the military men who use the arms from whom the 
 manufacturer has to take his directions as to the kind of arms 
 that are wanted, and again it is the statesman to whom the 
 professional soldiers have to look for directions as to when 
 and with what general objects in view they shall fight. So 
 the art which uses the things produced by another art is the 
 superior and directing art ; the art which makes the things, 
 the inferior and subordinate art. Hence the supreme practical 
 art is politics, since it is the art which uses the products 
 turned out by all other arts as means to its ends. It is the 
 business of politics, the art of the statesman, to prescribe to 
 the practitioners of all other arts and professions the lines 
 on which and the conditions under which they shall exercise 
 their vocation with a view to securing the supreme practical 
 end, the well-being of the community. Among the other 
 professions and arts which make the materials the statesman 
 employs, the profession of the educator stands foremost. The 
 statesman is bound to demand certain qualities of mind and 
 character in the individual citizens. The production of these 
 mental and moral qualities must therefore be the work of the 
 educator. It thus becomes an important branch of politics 
 to specify the kind of mental and moral qualities which a 
 statesman should require the educator to produce in his 
 pupils. 
 
 It is this branch of politics which Aristotle discusses in his 
 Ethics. He never contemplates a study of the individual's 
 good apart from politics, the study of the good of the society. 
 What then is the good or the best kind of life for an individual 
 member of society ? Aristotle answers that as far as the mere 
 name is concerned, there is a general agreement to call the best 
 life, Eudaimonia, Happiness. But the real problem is one of 
 fact. What kind of life deserves to be called happiness? 
 Plato had laid it down that the happy life must satisfy three 
 conditions. It must be desirable for its own sake, it must be 
 sufficient of itself to satisfy us, and it must be the life a wise
 
 74 ARISTOTLE 
 
 man would prefer to any other. The question is , What general 
 formula can we find which will define the life which satisfies 
 these conditions ? To find the answer we have to consider what 
 Plato and Aristotle call the work or function of man. By the 
 work of anything we mean what can only be done by it, or by 
 it better than by anything else. Thus the work of the eye is 
 to see. You cannot see with any other organ, and when the 
 eye does this work of seeing well you say it is a good eye. So 
 we may say of any living being that its work is to live, and 
 that it is a good being when it does this work of living efficiently. 
 To do its own work efficiently is the excellence or virtue of the 
 thing. The excellence or virtue of a man will thus be to live 
 efficiently, but since life can be manifested at different levels, 
 if we would know what man's work is we must ask whether 
 there is not some form of life which can only be lived by man. 
 Now the life which consists in merely feeding and growing 
 belongs to all organisms and can be lived with equal vigour by 
 them all. There is, however, a kind of life which can only be 
 lived by man, the life which consists in conscious direction of 
 one's actions by a rule. It is the work of man to live this 
 kind of life, and his happiness consists in living it efficiently 
 and well. So we may give as the definition of human well- 
 being that it is " an active life in accord with excellence, or if 
 there are more forms of excellence than one, in accord with the 
 best and completest of them " ; and we must add " in a com- 
 plete life" to show that mere promise not crowned by per- 
 formance does not suffice to entitle man's life to be called 
 happy. We can see that this definition satisfies Plato's three 
 conditions. A vigorous and active living in a way which calls 
 into play the specifically human capacities of man is desirable 
 for its own sake, and preferable to any other life which could be 
 proposed to us. It too is the only life which can permanently 
 satisfy men, but we must add that if such a life is to be lived 
 adequately certain advantages of fortune must be presupposed. 
 We cannot fully live a life of this kind if we are prevented 
 from exercising our capacities by lack of means or health or 
 friends and associates, and even the calamities which arise in 
 the course of events may be so crushing as to hinder a man, 
 for a time, from putting forth his full powers. These external 
 good things are not constituents of happiness, but merely neces-
 
 PRACTICAL PHILOSOPHY 75 
 
 sary conditions of that exercise of our own capacities which is 
 the happy life. 
 
 In our definition of the happy life we said that it was one 
 of activity in accord with goodness or excellence, and we left 
 it an open question whether there are more kinds of such good- 
 ness than one. On consideration we see that two kinds of 
 goodness or excellence are required in living the happy life. 
 The happy life for man is a life of conscious following of a 
 rule. To live it well, then, you need to know what the right 
 rule to follow is, and you need also to follow it. There are 
 persons who deliberately follow a wrong rule of life the 
 wicked. There are others who know what the right rule is 
 but fail to follow it because their tempers and appetites are 
 unruly the morally weak. To live the happy life, then, two 
 sorts of goodness are required. You must have a good judg- 
 ment as to what the right rule is (or if you cannot find it out 
 for yourself, you must at least be able to recognise it when it 
 is laid down by some one else, the teacher or lawgiver), and 
 you must have your appetites, feelings, and emotions generally 
 so trained that they obey the rule. Hence excellence, goodness, 
 or virtue is divided into goodness of intellect and goodness of 
 character (moral goodness), the word character being used for 
 the complex of tempers, feelings, and the affective side of 
 human nature generally. In education goodness of character 
 has to be produced by training and discipline before goodness 
 of intellect can be imparted. The young generally have to be 
 trained to obey the right rule before they can see for themselves 
 that it is the right rule, and if a man's tempers and passions 
 are not first schooled into actual obedience to the rule he will 
 in most cases never see that it is the right rule at all. Hence 
 Aristotle next goes on to discuss the general character of the 
 kind of goodness he calls goodness of character, the right state 
 of the feelings and passions. 
 
 The first step towards understanding what goodness of 
 character is is to consider the way in which it is actually 
 produced. We are not born with this goodness of tempers and 
 feelings ready made, nor yet do we obtain it by theoretical 
 instruction ; it is a result of a training and discipline of the 
 feelings and impulses. The possibility of such a training is 
 due to the fact that feelings and impulses are rational capacities,
 
 76 ARISTOTLE 
 
 and a rational capacity can be developed into either of two 
 contrasted activities according to the training it receives. You 
 cannot train stones to fall upwards, but you can train a hot 
 temper to display itself either in the form of righteous resent- 
 ment of wrong-doing or in that of violent defiance of all autho- 
 rity. Our natural emotions and impulses are in themselves 
 neither good nor bad ; they are the raw material out of which 
 training makes good or bad character according to the direction 
 it gives to them. The effect of training is to convert the 
 indeterminate tendency into a fixed habit. We may say, then, 
 that moral goodness is a fixed state of the soul produced by 
 habituation. By being trained in habits of endurance, self- 
 mastery, and fair dealing, we acquire the kind of character to 
 which it is pleasing to act bravely, continently, and fairly, and 
 disagreeable to act unfairly, profligately, or like a coward. 
 When habituation has brought about this result the moral 
 excellences in question have become part of our inmost self and 
 we are in full possession of goodness of character. In a word, 
 it is by repeated doing of right acts that we acquire^ the right 
 kind of character. 
 
 But what general characteristics distinguish right acts and 
 right habits from wrong ones? Aristotle is guided in answer- 
 ing the question by an analogy which is really at the bottom 
 of all Greek thinking on morality. The thought is that good- 
 ness is in the soul what health and fitness are in the body, and 
 that the preceptor is for the soul what the physician or the 
 trainer is for the body. Now it was a well-known medical 
 theory, favoured by both Plato and Aristotle, that health in 
 the body means a condition of balance or equilibration among 
 the elements of which it is composed. When the hot and the 
 cold, the moist and the dry in the composition of the human 
 frame exactly balance one another, the body is in perfect 
 health. Hence the object of the regimen of the physician or 
 the trainer is to produce and maintain a proper balance or 
 proportion between the ingredients of the body. Any course 
 which disturbs this balance is injurious to health and strength. 
 You damage your health if you take too much food or exercise, 
 and also if you take too little. The same thing is true of 
 health in the soul. Our soul's health may be injured by 
 allowing too much or too little play to any of our natural
 
 PRACTICAL PHILOSOPHY 77 
 
 impulses or feelings. We may lay it down, then, that the kind 
 of training which gives rise to a good habit is training in the 
 avoidance of the opposite errors of the too much and the too 
 little. And since the effect of training is to produce habits 
 which issue in the spontaneous performance of the same kind 
 of acts by which the habits were acquired, we may say not 
 merely that goodness of character is produced by acts which 
 exhibit a proper balance or mean, but that it is a settled habit 
 of acting so as to exhibit the same balance or proportion. 
 Hence the formal definition of goodness of character is that it 
 is " a settled condition of the soul which wills or chooses the 
 mean relatively to ourselves, this mean being determined by a 
 rule or whatever we like to call that by which the wise man 
 determines it." 
 
 There are several points in this definition of the mean upon 
 which moral virtue depends of which we must take note unless 
 we are to misunderstand Aristotle seriously. To begin with, 
 the definition expressly says that " moral goodness is a state 
 of will or choice." Thus it is not enough that one should 
 follow the rule of the mean outwardly in one's actions ; one's 
 personal will must be regulated by it. Goodness of character 
 is inward ; it is not merely outward. Next we must not sup- 
 pose that Aristotle means that the " just enough " is the same 
 for all our feelings, that every impulse has a moral right to 
 the same authority in shaping our conduct as any other. How 
 much or how little is the just enough in connection with a 
 given spring of action is one of the things which the wise man's 
 rule has to determine, just as the wise physician's rule may 
 determine that a very little quantity is the just enough in the 
 case of some articles of diet or curative drugs, while in the case 
 of others the just enough may be a considerable amount. Also 
 the right mean is not the same for every one. What we have 
 to attain is the mean relatively to ourselves, and this will be 
 different for persons of different constitutions and in different 
 conditions. It is this relativity of the just enough to the 
 individual's personality and circumstances which makes it im- 
 possible to lay down precise rules of conduct applicable alike 
 to everybody, and renders the practical attainment of goodness 
 so hard. It is my duty to spend some part of my income in 
 buying books on philosophy, but no general rule will tell me
 
 78 ARISTOTLE 
 
 what percentage of my income is the right amount for me to 
 spend in this way. That depends on a host of considerations, 
 such as the excess of my income above my necessary expenses 
 and the like. Or again, the just enough may vary with the 
 same man according to the circumstances of the particular case. 
 No rule of thumb application of a formula will decide such 
 problems. Hence Aristotle insists that the right mean in the 
 individual case has always to be determined by immediate in- 
 sight. This is precisely why goodness of intellect needs to be 
 added to goodness of character. His meaning is well brought 
 out by an illustration which I borrow from Professor Burnet. 
 "On a given occasion there will be a temperature which is 
 just right for my morning bath. If the bath is hotter than 
 this, it will be too hot ; if it is colder, it will be too cold. But 
 as this just right temperature varies with the condition of my 
 body, it cannot be ascertained by simply using a thermometer. 
 If I am in good general health I shall, however, know by the 
 feel of the water when the temperature is right. So if I am in 
 good moral health I shall know, without appealing to a formal 
 code of maxims, what is the right degree, e.g. of indignation to 
 show in a given case, how it should be shown and towards 
 whom." Thus we see why Aristotle demands goodness of 
 character as a preliminary condition of goodness of intellect or 
 judgment in moral matters. Finally, if we ask by what rule 
 the mean is determined, the answer will be that the rule is the 
 judgment of the legislator who determines what is the right 
 mean by his knowledge of the conditions on which the well- 
 being of the community depends. He then embodies his in- 
 sight in the laws which he makes and the regulations he im- 
 poses on the educators of youth. The final aim of education 
 in goodness is to make our immediate judgment as to what is 
 right coincide with the spirit of a wise legislation. 
 
 The introduction of the reference to will or choice into the 
 definition of goodness of character leads Aristotle to consider 
 the relation of will to conduct. His main object is to escape 
 the paradoxical doctrine which superficial students might 
 derive from the works of Plato, that wrong-doing is always 
 well-meaning ignorance. Aristotle's point is that it is the 
 condition of will revealed by men's acts which is the real 
 object of our approval or blame. This is because in voluntary
 
 PRACTICAL PHILOSOPHY 79 
 
 action the man himself is the efficient cause of his act. Hence 
 the law recognises only two grounds on which a man may 
 plead, that he is not answerable for what he does. (1) Actual 
 physical compulsion by force majeure. (2) Ignorance, not due 
 to the man's own previous negligence, of some circumstances 
 material to the issue. When either of these pleas can be 
 made with truth the man does not really contribute by his 
 choice to the resulting act, and therefore is not really its cause. 
 But a plea of ignorance of the general laws of morality does 
 not excuse. I cannot escape responsibility for a murder by 
 pleading that I did not know that murder is wrong. Such a 
 plea does not exempt me from having been the cause of the 
 murder ; it only shows that my moral principles are depraved. 
 
 More precisely will is a process which has both an intel- 
 lectual and an appetitive element. The appetitive element is 
 our wish for some result. The intellectual factor is the cal- 
 culation of the steps by which that result may be obtained. 
 When we wish for the result we begin to consider how it 
 might be brought about, and we continue our analysis until 
 we find that the chain of conditions requisite may be started 
 by the performance of some act now in our power to do. Will 
 may thus be defined as the deliberate appetition of something 
 within our power, and the very definition shows that our 
 choice is an efficient cause of the acts we choose to do. This 
 is why we rightly regard men as responsible or answerable for 
 their acts of choice, good and bad alike. 
 
 From the analysis of goodness of character, we proceed to 
 that of goodness of intellect. The important point is to 
 decide which of all the forms of goodness of intellect is that 
 which must be combined with goodness of character to make a 
 man fit to be a citizen of the state. It must be a kind of 
 intellectual excellence which makes a man see what the right 
 rule by which the mean is determined is. Now when we come 
 to consider the different excellences of intellect we find that 
 they all fall under one of two heads, theoretical or speculative 
 wisdom and practical wisdom. 
 
 Theoretical wisdom is contained in the sciences which give 
 us universal truths about the fixed and unalterable relations 
 of the things in the universe, or, as we should say, which teach 
 us the laws of Nature. Its method is syllogism, the function 
 
 F
 
 80 ARISTOTLE 
 
 of which is to make us see how the more complex truths are 
 implied in simpler principles. Practical wisdom is intelligence 
 as employed in controlling and directing human life to the 
 production of the happy life for a community, and it is this 
 form of intellectual excellence which we require of the states- 
 man. It is required of him not only that he should know in 
 general what things are good for man, but also that he should 
 be able to judge correctly that in given circumstances such and 
 such an act is the one which will secure the good. He must 
 not only know the right rule itself, which corresponds to the 
 major premiss of syllogism in theoretical science, but he must 
 understand the character of particular acts so as to see that 
 they fall under the right rule. Thus the method of practical 
 wisdom will be analogous to that of theoretical wisdom. In 
 both cases what we have to do is to see that certain special 
 facts are cases of a general law or rule. Hence Aristotle calls 
 the method of practical wisdom the practical syllogism or 
 syllogism of action, since its peculiarity is that what issues 
 from the putting together of the premisses is not an assertion 
 but the performance of an act. In the syllogism of action, the 
 conclusion, that is to say, the performance of a given act, just 
 as in the syllogism of theory, is connected with the rule given 
 in the major premiss by a statement of fact; thus e.g. the 
 performance of a specific act such as the writing of this book 
 is connected with the general rule what helps to spread 
 knowledge ought to be done by the conviction that the writing 
 of this book helps to spread knowledge. Our perception of 
 such a fact is like a sense-perception in its directness and 
 immediacy. We see therefore that the kind of intellectual 
 excellence which the statesman must possess embraces at once 
 a right conception of the general character of the life which is 
 best for man, because it calls into play his specific capacities 
 as a human being, and also a sound judgment in virtue of which 
 he sees correctly that particular acts are expressions of this 
 good for man. This, then, is what we mean by practical 
 wisdom. 
 
 So far, then, it would seem that the best life for man is just 
 the life of co-operation in the life of the state, which man, 
 being the only political animal or animal capable of life in a 
 state, has as his peculiar work, and as if the end of all moral
 
 PRACTICAL PHILOSOPHY 81 
 
 education should be to make us good and efficient citizens. 
 But in the Ethics, as elsewhere, the end of Aristotle's argu- 
 ment has a way of forgetting the beginning. We find that 
 there is after all a still higher life open to man than that of 
 public affairs. Affairs and business of all kinds are only 
 undertaken as means to getting leisure, just as civilised men 
 go to war, not for the love of war itself, but to secure peace. 
 The highest aim of life, then, is not the carrying on of political 
 business for its own sake, but the worthy and noble employ- 
 ment of leisure, the periods in which we are our own masters. 
 It has the advantage that it depends more purely on ourselves 
 and our own internal resources than any other life of which 
 we know, for it needs very little equipment with external goods 
 as compared with any form of the life of action. It calls into 
 play the very highest of our own capacities as intelligent 
 beings, and for that very reason the active living of it is 
 attended with the purest of all pleasures. In it, moreover, we 
 enter at intervals and for a little while, so far as the conditions 
 of our mundane existence allow, into the life which God enjoys 
 through an unbroken eternity. Thus we reach the curious 
 paradox that while the life of contemplation is said to be that 
 of our truest self, it is also maintained that this highest and 
 happiest life is one which we live, not in respect of being 
 human, but in respect of having a divine something in us. 
 When we ask what this life of contemplation includes, we see 
 from references in the Politics that it includes the genuinely 
 aesthetic appreciation of good literature and music and pictorial 
 and plastic art, but there can be no doubt that what bulks 
 most largely in Aristotle's mind is the active pursuit of science 
 for its own sake, particularly of such studies as First Philo- 
 sophy and Physics, which deal with the fundamental structure of 
 the universe. Aristotle thus definitely ends by placing the life 
 of the scholar and the student on the very summit of felicity. 
 
 It is from this doctrine that medieval Christianity derives 
 its opposition between the vita contemplative!, and vita 
 activa and its preference for the former, though in the 
 mediaeval mind the contemplative life has come to mean 
 generally a kind of brooding over theological speculations and of 
 absorption in mystical ecstasy very foreign to the spirit of 
 Aristotle. The types by which the contrast of the two lives is
 
 82 ARISTOTLE 
 
 illustrated, Rachael and Leah, Mary and Martha, are familiar 
 to all readers of Christian literature. 
 
 The Theory of the State. Man is by nature a political 
 animal, a being who can only develop his capacities by sharing 
 in the life of a community. Hence Aristotle definitely rejects 
 the view that the state or society is a mere creature of con- 
 vention or agreement, an institution made by compact between 
 individuals for certain special ends, not growing naturally out of 
 the universal demands and aspirations of humanity. Mankind, 
 he urges, have never existed at all as isolated individuals. Some 
 rudimentary form of social organisation is to be found wherever 
 men are to be found. The actual stages in the development of 
 social organisation have been three the .family, the village 
 community, the city state. In the very rudest forms of social 
 life known to us, the patriarchal family, not the individual, is 
 the social unit. Men lived at first in separate families under 
 the control of the head of the family. Now a family is made 
 up in its simplest form of at least three persons, a man, his wife, 
 and a servant or slave to do the hard work, though very poor 
 men often have to replace the servant by an ox as the drudge 
 of all work. Children when they come swell the number, and 
 thus we see the beginnings of complex social relations of sub- 
 ordination in the family itself. It involves three such distinct 
 relations, that of husband and wife, that of parent and child, 
 that of master and man. The family passes into the village 
 community, partly by the tendency of several families of 
 common descent to remain together under the direction of the 
 oldest male member of the group, partly by the association of a 
 number of distinct families for purposes of mutual help and 
 protection against common dangers. Neither of these forms of 
 association, however, makes adequate provision for the most 
 permanent needs of human nature. Complete security for a 
 permanent supply of material necessaries and adequate protec- 
 tion only come when a number of such scattered communities 
 pool their resources, and surround themselves with a city wall. 
 The city state, which has come into being in this way, proves 
 adequate to provide from its own internal resources for all the 
 spiritual as well as the material needs of its members. Hence 
 the independent city state does not grow as civilisation advances 
 into any higher form of organisation, as the family and village
 
 PRACTICAL PHILOSOPHY 83 
 
 grew into it. It is the end, the last word of social progress. 
 It is amazing to us that this piece of cheap conservatism should 
 have been uttered at the very time when the system of inde- 
 pendent city states had visibly broken down, and a former 
 pupil of Aristotle himself was founding a gigantic empire to 
 take their place as the vehicle of civilisation. 
 
 The end for which the state exists is not merely its own self- 
 perpetuation. As we have seen, Aristotle assigns a higher 
 value to the life of the studenj than to the life of practical 
 affairs. Since it is only in the civilised state that the student 
 can pursue his vocation, the ultimate reason for which the state 
 exists is to educate its citizens in such a way as shall fit them 
 to make the noble use of leisure. In the end the state itself is 
 a means to the spiritual cultivation of its individual members. 
 This implies that the chosen few., who have a vocation to make 
 full use of the opportunities provided for leading this life of noble 
 leisure, are the real end for the sake of which society exists. 
 The other citizens who have no qualification for any life higher 
 than that of business and affairs are making the most of them- 
 selves in devoting their lives to the conduct and maintenance 
 of the organisation whose full advantages they are unequal to 
 share in. It is from this point of view also that Aristotle treats 
 the social problem of the existence of a class whose whole life 
 is spent in doing the hard work of society, and thus setting the 
 citizen body free to make the best use it can of leisure. In the 
 conditions of life in the Greek world this class consisted mainly 
 of slaves, and thus the problem Aristotle has to face is the 
 moral justifiability of slavery. We must remember that he 
 knew slavery only in its comparatively humane Hellenic form. 
 The slaves of whom he speaks were household servants and 
 assistants in small businesses. He had not before his eyes the 
 system of enormous industries carried on by huge gangs of 
 slaves under conditions of revolting degradation which disgraced 
 the later Roman Republic and the early Roman Empire, or the 
 Southern States of North^ America. His problems are in all 
 essentials much the same as those which concern us to-day in 
 connection with the social position of the classes who do the 
 hard bodily work of the community. 
 
 Much consideration is given in the Politics to the classifica- 
 tion of the different types of constitution possible for the city-
 
 84 ARISTOTLE 
 
 state. The current view was that there are three main types 
 distinguished by the number of persons who form the sovereign 
 political authority, monarchy, in which sovereign power belongs 
 to a single person ; oligarchy, in which it is in the hands of a 
 select few ; democracy, in which it is enjoyed by the whole body 
 of the citizens. Aristotle observes, correctly, that the really 
 fundamental distinction between a Qjfifik oligarchy and a 
 Greek democracy was that the former was government by the 
 propertied classes, the latter government by the masses. Hence 
 the watchword of democracy was always that all political 
 rights should belong equally to all citizens, that of oligarchy 
 that a man's political status should be graded according to his 
 " stake in the country." Both ideals are, according to him, 
 equally mistaken, since the real end of government, which both 
 overlook, is the promotion of the "good life." In a state 
 which recognises this ideal, an aristocracy or government by 
 the best, only the " best " men will possess the full rights of 
 citizenship, whether they are many or few. There might even 
 be a monarch at the head of such a state, if it happened to 
 contain some one man of outstanding intellectual and moral 
 worth. Such a state should be the very opposite of a great 
 imperial power. It should, that its cultivation may be the 
 more intensive, be as small as is compatible with complete 
 independence of outside communities for its material and 
 spiritual sustenance, and its territory should only be large 
 enough to provide its members with the, permanent possibility 
 of ample leisure, so long as they are content with plain and 
 frugal living. Though it ought not, for military and other 
 reasons, to be cut off from communication with the sea, the 
 great military and commercial high road of the Greek world, it 
 ought not to be near enough to the coast to run any risk of 
 imperilling its moral cultivation by becoming a great emporium, 
 like the Athens of Pericles. In the organisation of the society 
 care should be taken to exclude the agricultural and industrial 
 population from full citizenship, which carries with it the 
 right to appoint and to be appointed as administrative magis- 
 trates. This is because these classes, having no opportunity 
 for the worthy employment of leisure, cannot be trusted to 
 administer the state for the high ends which it is its true 
 function to further.
 
 PRACTICAL PHILOSOPHY 85 
 
 Thus Aristotle's political ideal is that of a small but 
 and highly cultivated aristocracy, without large fortunes or any 
 remarkable differences in material wealth, free from the spirit 
 of adventure and enterprise, pursuing the arts and sciences 
 quietly while its material needs are supplied by the labour nf 
 a class excluded from citizenship, kindly treated but without 
 prospects. Weimar, in the days when Thackeray knew it 
 as a lad, would apparently reproduce the ideal better than any 
 other modern state one can think of. 
 
 The object of the Politics is, however, not merely to discuss 
 the ideal state but to give practical advice to men who might 
 be looking forward to actual political life, and would therefore 
 largely have to be content with making the best of existing 
 institutions. In the absence of the ideal aristocracy, Aristotle's 
 preference is for what he calls Polity or constitutional govern- 
 ment, a sort of compromise between oligarchy and democracy. 
 Of course a practical statesman may have to work with a theo- 
 retically undesirable constitution, such as an oligarchy or an 
 unqualified democracy. But it is only in an ideal constitution 
 that the education which makes its subject a good man, in the 
 philosopher's sense of the word, will also make him a good 
 citizen. If the constitution is bad, then the education best 
 fitted to make a man loyal to it may have to be very different 
 from that which you would choose to make him a good man. 
 The discussion of the kind of education desirable for the best 
 kind of state, in which to be a loyal citizen and to be a good 
 man are the same thing, is perhaps the most permanently 
 valuable part of the Politics. Though Aristotle's writings on 
 " practical " philosophy have been more read in modern times 
 than any other part of his works, they are far from being his 
 best and most thorough performances. In no department of 
 his thought is he quite so slavishly dependent on his master 
 Plato as in the theory of the " good for man " and the character 
 of " mdral " excellence. No Aristotelian work is quite so 
 commonplace in its handling of a vast subject as the Politics. 
 In truth his interest in these social questions is not of the 
 deepest. He is, in accordance with his view of the superiority 
 of " theoretical science," entirely devoid of the spirit of the 
 social reformer. What he really cares about is " theology " 
 and " physics," and the fact that the objects of the educational
 
 86 ARISTOTLE 
 
 regulations of the Politics are all designed' to encourage the 
 study of these " theoretical " sciences, makes this section of the 
 Politics still one of the most valuable expositions of the aims 
 and requirements of a " liberal " education. 
 
 All education must be under public control, and education 
 must be universal and compulsory. Public control is necessary, 
 not merely to avoid educational anarchy, but because it is 
 a matter of importance to the community that its future 
 citizens should be trained in the way which will make them 
 most loyal to the constitution and the ends it is designed to 
 subserve. Even in one of the "bad" types of state, where 
 the life which the constitution tends to foster is not the 
 highest, the legislator's business is to see that education is 
 directed towards fostering the "spirit of the constitution." 
 There is to be an " atmosphere " which impregnates the whole 
 of the teaching, and it is to be an " atmosphere " of public 
 spirit. The only advantage which Aristotle sees in private 
 education is that it allows of more modification of programme 
 to meet the special needs of the individual pupil than a 
 rigid state education which is to be the same for all. The 
 actual regulations which Aristotle lays down are not very 
 different from those of Plato. Both philosophers hold that 
 "primary" education, in the early years of life, should aim 
 partly at promoting bodily health and growth by a proper 
 system of physical exercises, partly at influencing character and 
 giving a refined and elevated tone to the mind by the study 
 of letters, art, and music. Both agree that this should be 
 followed in the later " teens " by two or three years of specially 
 rigorous systematic military training combined with a taste 
 of actual service in the less exhausting and less dangerous 
 parts of a soldier's duty. It is only after this, at about the 
 age at which young men now take a " university " course, that 
 Plato and Aristotle would have the serious scientific training 
 of the intellect begun. The Politics leaves the subject just at 
 the point where the young men are ready to undergo their 
 special military training. Thus we do not know with certainty 
 what scientific curriculum Aristotle would have recommended, 
 though we may safely guess that it would have contained 
 comparatively little pure mathematics, but a great deal of 
 astronomy, cosmology, and biology.
 
 PRACTICAL PHILOSOPHY 87 
 
 With respect to the " primary " education Aristotle has a 
 good deal to say. As " forcing " is always injurious, it should 
 not be begun too soon. For the first five years a child's life 
 should be given up to healthy play. Great care must be taken 
 that children are not allowed to be too much with "servants," 
 from whom they may imbibe low tastes, and that they are 
 protected against any familiarity with indecency. From five 
 to seven a chrld may begin to make a first easy acquaintance 
 with the life of the school by looking on at the lessons of its 
 eiders. The real work of school education is to begin at seven 
 and not before. 
 
 We next have to consider what should be the staple subjects 
 of an education meant not for those who are to follow some 
 particular calling, but for all the full citizens of a state. 
 Aristotle's view is that some " useful " subjects must, of course, 
 be taught. Reading and writing, for instance, are useful for 
 the discharge of the business of life, though their commercial 
 utility is not the highest value which they have for us. But 
 care must be taken that only those " useful " studies which are 
 also " liberal " should be taught ; " illiberal " or " mechanical " 
 subjects must not have any place in the curriculum. A 
 " liberal " education means, as the name shows, one which will 
 tend to make its recipient a " free man," and not a slave in 
 body and soul. The mechanical crafts were felt by Aristotle 
 to be illiberal because they leave a man no leisure to make the 
 best of body and mind ; practice of them sets a stamp on the 
 body and narrows the mind's outlook. In principle then, no 
 study should form a subject of the universal curriculum if its 
 only value is that it prepares a man for a profession followed 
 as a means of making a living. General education, all-round 
 training which aims at the development of body and mind for 
 its own sake, must be kept free from the intrusion of everything 
 which has a merely commercial value and tends to contract 
 the mental vision. It is the same principle which we rightly 
 employ ourselves when we maintain that a university education 
 ought not to include specialisation on merely " technical " or 
 " professional " studies. The useful subjects which have at the 
 same time a higher value as contributing to the formation of 
 taste and character and serving to elevate and refine the mind 
 include, besides reading and writing, which render great litera-
 
 88 ARISTOTLE 
 
 ture accessible to us, bodily culture (the true object of which 
 is not merely to make the body strong and hardy, but to de- 
 velop the moral qualities of grace and courage), music, and 
 drawing. Aristotle holds that the real reason for making 
 children learn music is (1) that the artistic appreciation of 
 really great music is one of the ways in which " leisure " may 
 be worthily employed, and to appreciate music rightly we must 
 have some personal training in musical execution ; (2) that all 
 art, and music in particular, has a direct influence on character. 
 
 Plato and Aristotle, though they differ on certain points of 
 detail, are agreed that the influence of music on character, for 
 good or bad, is enormous. MusiCj they say, is the most imita- 
 tive of all the arts. The various rhythms, times, and scales 
 imitate different tempers and emotional moods, and it is a 
 fundamental law of our nature that we grow like what we take 
 pleasure in seeing or having imitated or represented for us. 
 Hence if we are early accustomed to take pleasure in the imita- 
 tion of the manly, resolute, and orderly, these qualities will in 
 time become part of our own nature. This is why right 
 musical education is so important that Plato declared that the 
 revolutionary spirit always makes its first appearance in inno- 
 vations on established musical form. 
 
 There is, however, one important difference between the two 
 philosophers which must be noted, because it concerns Aris- 
 totle's chief contribution to the philosophy of fine art. Plato 
 had in the Republic proposed to expel florid, languishing, or 
 unduly exciting forms of music not only from the schoolroom, 
 but from life altogether, on the ground of their unwholesome 
 tendency to foster an unstable and morbid character in those 
 who enjoy them. For the same reason he had proposed the 
 entire suppression of tragic drama. Aristotle has a theory 
 which is directly aimed against this overstrained Puritanism. 
 He holds that the exciting and sensational art which would be 
 very bad as daily food may be very useful as an occasional 
 medicine for the soul. He would retain even the most sensa- 
 tional forms of music on account of what he calls their "purga- 
 Jjve " value. In the same spirit he asserts that the function 
 of tragedy, with its sensational representations of the calamities 
 of its heroes, is " by the vehicle of fear and pity to purge our 
 minds of those and similar emotions." The explanation of the
 
 PRACTICAL PHILOSOPHY 89 
 
 theory is to be sought in the literal sense of the medical term 
 " purgative." According to the medical view which we have 
 already found influencing his ethical doctrine, health consists 
 in the maintenance of an equality between the various in- 
 gredients of the body. Every now and again it happens that 
 there arise superfluous accretions of some one ingredient, which 
 are not carried away in the normal routine of bodily life. 
 These give rise to serious derangement of function and may 
 permanently injure the working of the organism, unless they 
 are removed in time by a medicine which acts as a purge, and 
 clears the body of a superfluous accumulation. The same thing 
 also happens in the life of the soul. So long as we are in good 
 spiritual health our various feelings and emotional moods will 
 be readily discharged in action, in the course of our daily life. 
 But there is always the possibility of an excessive accumulation 
 of emotional " moods " for which the rputine of daily life does 
 not provide an adequate discharge in action. Unless this 
 tendency is checked we may contract dangerously morbid habits 
 of soul. Thus we need some medicine for the soul against this 
 danger, which may be to it what a purgative is to the body. 
 
 Now it was a well-known fact, observed in connection with 
 some of the more extravagant religious cults, that persons 
 suffering from an excess of religious frenzy might be cured 
 homoeopathically, so to say, by artificially arousing the very 
 emotion in question by the use of exciting music. Aristotle 
 extends the principle by suggesting that in the artificial excite- 
 ment aroused by violently stimulating music or in the trans- 
 ports of sympathetic apprehension and pity with which we 
 follow the disasters of the stage-hero, we have a safe and ready 
 means of ridding ourselves of morbid emotional strain which 
 might otherwise have worked havoc with the efficient conduct 
 of real life. 
 
 The great value of this defence of the occasional employment 
 of sensation as a medicine for the soul is obvious. Unhappily 
 it would seem to have so dominated Aristotle's thought on the 
 functions of dramatic art as to blind him to what we are 
 accustomed to think the nobler functions of tragedy. No book 
 has had a more curious fate than the little manual for intend- 
 ing composers of tragedies which is all that remains to us of 
 Aristotle's lectures on Poetry. This is not the place to tell
 
 90 ARISTOTLE 
 
 the story of the way in which the great classical French play- 
 wrights, who hopelessly misunderstood the meaning of Aris- 
 totle's chief special directions, but quite correctly divined that 
 his lectures were meant to be an actual Vade Mecum for 
 the dramatist, deliberately constructed their masterpieces in 
 absolute submission to regulations for which they had no better 
 reasons than that they had once been given magisterially by an 
 ancient Greek philosopher. But it may be worth while to 
 remark that the worth of Aristotle's account of tragedy as art- 
 criticism has probably been vastly overrated. From first to 
 last the standpoint he assumes, in his verdicts on the great 
 tragic poets, is that of the gallery. What he insists on all 
 through, probably because he has the purgative effect of the 
 play always in his mind, is a well-woven plot with plenty of 
 melodramatic surprise in the incidents and a thoroughly sensa- 
 tional culmination in a sense of unrelieved catastrophe over 
 which the spectator can have a good cry, and so get well 
 " purged " of his superfluous emotion. It is clear from his 
 repeated allusions that the play he admired above all others 
 was the King Oedipus of Sophocles, but it is equally clear 
 that he admired it not for the profound insight into human life 
 and destiny or the deep sense of the mystery of things which 
 some modern critics have found in it, but because its plot is 
 the best and most startling detective story ever devised, and 
 its finale a triumph of melodramatic horror.
 
 BIBLIOGRAPHY 
 
 The English reader who wishes for further information about 
 Aristotle and his philosophy may be referred to any or all of the 
 following works : 
 
 E. Zeller. Aristotle and the Earlier Peripatetics. English trans- 
 lation in 2 vols. by B. F. C. Costelloe and J. H. Muirhead. 
 London. Longmans & Co. 
 
 *E. Wallace. Outlines of the Philosophy of Aristotle. Cambridge 
 
 University Press. 
 G. Grote. Aristotle. London. John Murray. 
 
 *W. D. Ross. The Works of Aristotle translated into English, vol. 
 viii., Metaphysics. Oxford. Clarendon Press. 
 
 *A. E. Taylor. Aristotle on his Predecessors. (Metaphysics, Bk. I., 
 translated with notes, &c.) Chicago. Open Court Pub- 
 lishing Co. 
 
 G. D. Hicks. Aristotle de Anima (Greek text, English translation, 
 Commentary). Cambridge University Press. 
 
 *D. P. Chase. The Ethics of Aristotle. Walter Scott Co. 
 
 *J. Burnet. Aristotle on Education. (English translation of Ethics, 
 Bks. I.-III. 5, X. 6 to end; Politics, VIII. 17, VIII.) 
 Cambridge University Press. 
 
 *B. Jowett. The Politics of Aristotle. Oxford. Clarendon Press. 
 
 *I. Bywater. Aristotle on the Art of Poetry. (Greek Text, English 
 
 Translation, Commentary.) Oxford. Clarendon Press. 
 J. I. Beare and W. D. Ross. The Works of Aristotle translated into 
 English, Pt. I. (Parva Naturalia, the minor psychological 
 works.) Oxford. Clarendon Press. 
 
 J. I. Beare. Greek Theories of Elementary Cognition from AlcmacuH 
 to Aristotle. Oxford. Clarendon Press. 
 
 The works marked by an asterisk will probably be found most 
 useful for the beginner. No works in foreign languages and no 
 editions not accompanied by an English translation have been 
 mentioned. 
 
 There is at present no satisfactory complete translation of Aris- 
 totle into English. One, of which two volumes have been men- 
 tioned above, is in course of production at the Clarendon Press, 
 Oxford, under the editorship of J. A. Smith and W. D. Ross. 
 
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