THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES GIFT OF Dr. Sllen B. SulJivan ^J^i.^ /(!/ S^n^c/Z^e^^^t^^ OUTLINES OF- PSYCHOLOGY DICTATIONS FliO.M LECTURES — BY — HERMAN X LOTZH THAXSl.ATKl). WITH A CHAPTER OiJ THE AXATOMY OE THE BRAIN — BY — ('. L. HEKKICK. ILLUSTRATED- MIXXEAPOLLS. MIXX. S . M . WILLIAMS L. KIMBALL A: CO., riii.NT. library /33 PREFACE The tr;iiislati()ii of Lotze's G rtnxlziicijc dcr Psifrli- ohxjic. wliiih tonus the principal part of this l)()ok. was made in 1(S82. and it was expected to ])nblish it at once. Oircunistances prevente«I. for the time, the carrviui;" out of the phm. l)iit lately a ])ersonal need of some small text l»o(dc to use in couueetion witli the study of com-' jtarative auatomy in the scientific dejiartment of an underi;raduate course led to its revival. This circum- stance explains why the short chapter on anatomy has heen ai»])en(h^d unnecess:n'ily. as it may seem. It is be- lieved that, in its ju-esent form, this volume will ])rove convenient: firstly, for use in connection with the little that can usually he said n]»on the ]>hysiolou'y of the nervous svstem in the comj)arative anatomy of our ordinary colleecia] attention in tlie phi]oso])hical (h'partment. Of the value of Lotze's little woi'k nothing" need be said here, theyreat German ])hilosopher is ra])idly gaininj^ recognition even in 706494 IV I'KKFACE. America, while the series of " Outlines." of which this forms a ])art, has been exceed iiiiiiy wfU rt'crivcil ahroad. Attention may he' ask(-(l. howcvci'. to the fact thiit these are I)ut i>/tf/iiii'<: and emhnn-e hut tlic (lictatcd portions of an extended lectui'c course. TJicir use in the school room implies oral explaiiatiou aud illustra- tion, or. better, they uniy form the frame work for a lecture course which may deal a^ fully with auatomical and physiological details as time permits. It is a nnitter of regret that no English work iu this de]»artuient has as yet a])peared which is not devoted to the iudirect in- culcation of a theory (uuorthodox oi- otherwise ). or for some other reason unadapted to jdace iu the liaiids of college students. Of the writer's part of the work it is not becoming to speak further than to exj^ress the ho])e that the sacrifice of literal accuracy will be found to have been atteuih'd with compiuisating advantages in ]>erspicuity. The vei-y foi-cible and coluxpiial style, which is sf) strikiu^' iu the origiual. is verv hai'il to imitate, and one uuiy l>e satisheil if the atteiujit prove intellijicible. TABLE OF CONTENTS. IXTliOJM ( TION PAGE. - 1 PAKT FIliST. INDIVIDUAL P:LEMEXTS OF THE INNER LIFE. CirAi'TP:K FnjsT. — Simple Sen.-iatioiis . . . - 5 Skctiox 1. Detinitioiis — Excitations of Sense - - 5 Section 2. Nervous Action . . . . . .> Section 8. Sensation Pi-oper . . - . . 7 Section 4. CoiTesi)ondence between the Irritation and Sensation - - - - - - !• Section o. Duration of Sensation - . . . 10 Section 0. Intensity of Sensory Stimuli - - - 11 Section 7. Wel)er's Law - - - - - 18 Section 8. Increments in Intensity - - - 14 Section D. Periodicity of Sensory Stinuili - - IC Section 10. Subjective Sensation - - - -17 Section 11. Complexity of Or uans of Sense - - 19 Section 12. Subjectivity or Objectivity of Sensations - 20 Cii.\ptek Second. — The Process of Conception - 22 Section 1. Concepts distinjfuished from Sensations 22 Section 2. Unconscious Concept^ _ . . - 22 Section o. Memory 2:) Section 4. Vividness of Concepts - 24 Section o. Contents of Conce])tion - - 26 Section (i. The Power of Conce]its . . - . 2(> VI TABLE OF CONTEXTS. PA(!K. Skction 7. Assdciatioii <>t' Coiuepts - - - - 27 C'liAriKi! TniKi). — lichitivc KiiowIediiP and Atteiitioii . '.\\ Sk('1I()N 1. CDinparcd Concepts- .... :5l Skctiox 2. The F.iculty Involved in (oniparisnn - :>2 Section :>. General Notions :!2 Skctiox 4. Limitations of Co, sciousness - :{;! Skctiox 0. 01>servation and Attention - - :;4 Cii.M'TKii Fouin'H. — Tlie Intuitions of Space . - . :i(i Section 1. How is tlie Idea of Spice Produced - :!(; Section 3. Visual lieju-esentation .... :',(; Sectiox 8. The Soul L'nextended .... ;57 Section 4. Combination of Discrete Impressions ;!7 Skction .>. Orig'in of Spatial Intuitions Inexplicable :!S Section (5. Theory- of Local Indices ... ;;[<)tions - ('(i PART SECOND. THE SOLE. Cn.U'TKK FiKsT.- On tin- Ivxistencc of thn Soul - Tl Section I. ."Method of Study - - - - - 71 Section 2. -Materialistic Ex))lanation - - - 71 Sec'iion 8. Construction of Unity in Consciousness 72 Sec'I'ion 4. Doctrine of Monads - - - - - 78 Seciion 5. Bod}' and Soul - ----- 74 Ch Ai'TEK Second. Tiie Reciprocal Action Ketween Soul and J3ody - - - - 7(i Section 1. Ci^nditions of Heciprocity - - - 76 Section 2. Inai)p!ica1)ility of Mechanical Analogy - 70 Section 8. Cause of Correllatiou - . . . 77 Section 4. The Link Between Soul and Body - - 78 Section 5. The Notion of Matei'iality. - - - 7i» VIU TAHLK l)F ('()XTF:XT.S. PACK. CllAl'lKi; 'I'lllKD. 'I'lic Seat of the Soul - - - - 82 Skctiox 1. Position 82 Skctiox 2. Omniproscnce ..---. 82 Skctiox 'S. Physical Analogies Ai)plied to the (Jpeia- tioti of Psycliical Forces - - - 8:') Section 4. Soul Centers in the Brain - - - 84 Sectfox 5. A Fallacious Notion of Position - - 84 Section 6. The Soul and the Brain - - - . 8(5 SKCTtox 7. Partial Truth of .Materialism - - . 80 C'liAi'TKii Fix itrit. —The l{elation of the Soul to Time - 88 Section' 1. Immortality ------ 88 Skctiox 2. Substance as Explainin"- Existence - - 89 Sectiox 8. Essential Unity of Nature and the Condi- tioning Power of the Absolute - '.tO Section 4. Source of Permanency in Nature. (Figure omitted) - 91 Skctiox 5. Birth of the Soul - - - - . 92 Cii.vrTKU Fifth. — The Soul's Essence . - - . 93 Section 1. ^Meaning of Essence - . . . 9:! Section 2. The Doctrine of Faculties. (Figure omitted) ------- 94 Section 8. Ilerbart's E.xplanation - - - - 95 Section 4. The Soul's Act> not Automatic - - - 97 Sectiox 5. Idealistic Interpretation - . - - 98 ('ii.vrTEU Sixth. — The INIutable Coidition of the Soul - Idl Skcti(»x 1. The Conditions of the Soul's Action 1(»1 Sectiox 2. Unconsciousness ------ t(i2 Section :>. Hypnotism lii;> Section 4. Partial Unconsciousness . - . . 104 Section o. Corporeal Basis of Memory - - - Kt-") TAI'.I.K OF CONTENTS. IX I'AGIC. 8i:(Ti(iN (i. Dreamiim' ------- 106 Skction T Thf "rt'iuixT.niifnts ----- 107 Skction 8. Phreno'.oyy - 108 Skctiox !). Sensoriinn and ^lotoriuni CVniimune - 10!J Skction 10. C'Di-poreal Basis of Hi^licr Faculties - - 111 Skctiox 11. ^[nrliiil AcTivity Soiniiainlmh.iice - 112 Cn.\i'TEK SEvii;NTJi."-Tlif' Ucaiiii of Soul- - - - 114 Section 1. Animal and Plant Souls - - - - 114 Skction 2. Diversity of Souls - - - - - 11.5 Section '■). Humanity Distinguished l)y I'nderstand- in- - - IIT) Skction 4. Humanity Distiuiiiiislied ]iy Uea^on - - 117 Skction •"). Humanity Distiniruislied liy "\M11 - - 118 Skction (i. Fn-edom . victory and Sensoi-y Nerves - - - 128 Section (i. Chemical Constituents - - - - 180 Section 7. Form and Development of the Central Portion of the >;ervous System - - lo2 Section 8. Connection Between tiie Brain and f)ther parts of the Nervous System - - - lo8 Section 0. Physiology of the Brain - - - - 141 Section l(t. Development of Sensory Functions - - 143 INTRODUCTION. Sensations, conceptions, feelings, and acts of will con- stitute the group of familiar facts which we are accus- tomed to designate, although with a reservation in view of future discoveries, as the life of a peculiar being — tlie soul. In order to fully meet our scientific requiremeuts it is necessary, Jirsf, through the agenc}^ of observation, to completely set forth all the individual elements of this life and the general formulas for their combination — Dexcripti vp or Eiiq^ir ical Fsijc holof/ ij; secondh)., to spec- ify the nature of the subject in which this life subsists as well as those active forces and conditions by which this life is produced and caused to maintain that course with which experience has made us familiar — E.rpJatia- tonj or Mei(( pit ij deal Fsi/rhologij; Jiiudhj^ to give a rational explanation why all these facts exist, or, in general, the mission of soul-life in the world — Ideal or _Speci(lafire Psijeliologi^[. Now since the latter problem does not admit of a solution in strict scientific form, while the treatment of the first is easily coml>ined with that of the second, the question with which we are chiefly concerned is this: •"Under what conditions and INTRODUCTION. Itv means of what forces are the single processes of spiritual life produced: how are they united with. and modiiied by each other so as to produce, through their combined activity, the total of spiritual life." Our course is that offered ])y the phenomena them- selves, that is, we begin with external impressions, by which the spiritual activity is excited from moment to moment afresh, then consider the manifold internal transfurnuitions which these im})ressions undergo, lastly the retlex activities — motions or other acts — which re- sult from them. Only after the enumera ion of these individual ele- ments of the spiritual life is it i)ossil)le to pass to a com- prehensive consideration of the nature of that suliject Avhich controls this life. PART FIRST. The Individual l^Jements of the Inner IJfe. CHAPTER FIRST. SIMPLE SENSATIO>s'S. §1. We here understund by simple sensations tliose which evince no combination of similar or dis-similar parts, and we, furthermore, assume them to be induced (as is usually the case) by external impressions. In this case we distinguish in the production of a sen- sation, as the first process, the exiernaJ sense excitement. No object becomes, by virtue of its existence simply, an object of apprehension; it becomes such only as it either itself approaches to contact Avith our bod}*, as in the case of impact, or communicates to the surrounding medium motions which extend from element to element until at length they reach our body, as is the case with sound and light waves. In all cases, however, the external sensory stimulus is a motion of some sort or other and has no similarity to the mental processes which are evoked by it. §2. The second essential is that process in'thiii the body which is caused by the external excitement. By their contact with the body these external irritants pro- duce manifold changes in the external layers, of which we know little, and which we do not need to follow 6 OUTLINES OF PSYCHOLOGY. psychologically because they can only become the sources of sensation when they reach the ends of the nerves distributed tliroiinhout the l)ody. In them an excitement is produced which must extend through the entire length of the nerve-thread to the brain before a sensation can ])e produced. An injarv of the nerve, which })revents this trans- mission, results in the complete loss to consciousness of knowledge of the irritations in the perij_)heral nerve termini. In what that excitement known as the nervous action consists is not definitely ascertained. ])nt it is only im- portant ill psychology to answer the question whether this is siuiply a sort of physical motion or whether it already participates iu the character of psychical life. Sensation does not sim])ly exist at large in the nerves but we mnst explain just what it is that is affected by the sensation. The nerve as aAvholeit cannot be, for the nerve is an aggregate of many parts and. moreover, is never, as a whole, in a state of excitement but, on the contrary, one ])art is affected after another successively. It would therefore be necessary to assume that each indivisible atom of the nerve is a sensitive subject and each transmits its sensation to its neighbor until at last it reaches the soul. The fact that the transmission of the excitement may be prevented by alterations in the physical continuity of the nerve, as. for exami)le. by incision, shows that OUTLINES OF PSYCHOLOGY. this transmission is the resnlt, not of an immediate sym- ])athy. but of* a physical effect produced upon one nerve atom Ijy another. Then we must suppose that the atom ;i acts physic- ally upon the atom b and. as a result of this action, b enters the state of sensation E. Then atom b im])arts a physical impulse to atom c which thus, in turn, be- comes affected by the sensation E. The last nerve atom Z acts then, in a way entirely uukuown. upon the soul and now this also is so excited as to ])roduce its sensa- tion E, It is easy to see that this last impulse, by means of which our sensation ( which is. after all. the only thing of which we really know anything) is produced, would have exactly the same result if the nerve atoms exerted simply a physical influence upon each other and if their own sensations (which are simply assumptions and not discovered facts ) did not exist at all. Since the idea of sensation in the nerves themselves contributes nothing to the explanation of onr own sensations, and, more- over, is not demonstrable, while the passage of a ])hy- sical impulse can not l)e denied, we shall, in the future, consider the nervous action as simply physical motion which passes from one nerve element to another and which does not partake of the psychical nature charac- teristic of the resulting sensation. §3. The third link in this chain of processes is that OUTLINES OF PSYCHOLOGY. condition of consciousness so familiar to all, the sensa- tion itself — the act of seeing a light of a definite color or the hearing of a sound, for exauiple. Of the two elements in this process Avhicli we are able to distinguish in our thinking, namely the qualit- ative content, which we perceive, and the perceiving activity hy which it is made known to us. neither the one or the other is comparable Avith the nature of the external excitement or the nei've process. As accur- ately as we may analyze the nature of ether waves we never discover in them the reason why they are seen as light rather than heard as sound, nor why one sort is perceiyed as red and another as Ijlue and not the re- verse. Furthermore, however we may combine the physical motions of nerve atoms there never comes a point where it is clear that the motion last produced is not to remain motion l)ut must ])ass over into the en- tirely different process of sensation. Vain are all attempts to discover how it is that the simple i)hysical motion gradually passes over into sen- sation. We must, the rather, be content to state that nature has. by one of its imposed necessities, quite un- known to us, so correllated these two dissimilar series of • j^rocesses — motions and sensations — (which we are un- able to derive the one from the other) that a member of the one series always produces a definite member of the other. OUTLINES OF PSYCHOLOGY. 9 §4. It would 1)6 assumed that these two series of processes would not be linked together without system, but rather that similar excitements in one series would correspond to similar sensations in the other and differ- ent excitements to different sensations. And, when, in the series of stimuli, a definite progress, retardation, periodicity, or prominent elements occur it would be expected that, in some way, all these would find expres- sion in the corresponding series of sensations. This assumption is but partially supported by exper- ience. In the first place, the various classes of sensa- tions (^colors, sounds, odors) occur serially one after the other, forming no complete system. It does not in the least follow l^ecause we perceive ether waves as light that we must perceive air waves as sound. The same is true of the individual elements of the different classes. He whose experience of taste and sight was limited to the taste sour and the color yellow would not be led to susjiect the existence of bitter and blue. Again, it is only in the case of sounds that we find a definite progression in the series of excitements corres- ponding to a similar progressive arrangement of the series of sensations; the pitch of sounds increasing with the rapidity of the vibrations of the sound Avaves. It should here be noticed that the manner in which the sensations reflect the variation in the exciting cause is itself quite peculiar. The difference in pitch between tAvo tones has no similarity to the difference between 10 OUTLINES OF PSYCHOLOGY. two numbers, but expresses an entirely peculiar increase of qualitative intensity wliicli could not have been ex- pected and of which we have no other illustration. In like manner the rennirkable instance of the doul)- ling of the number of waves finds a ])eculiar expression in the octave, which is not perceived as the douljling of anything but as a remarkable coml)ination of identity and dissimilarity l»etween the tones nnexemidified else- where. On the other hand colors, although they correspond in their prismatic arrangement to a similarly increasing wave-rate, do not at all arrange their impressions in a series of increasing intensity. This discrepancy results from the fact that we can only legitimately ex])ect a correspondence between sensations and their immediate causes — the nerve-processes. The latter, however, we do not understand, and are forced to compare, in all cases, only the results of sensation with the external stimulus upon which, as we saw, they do not immedi- ately depend. Finally, since our sensations do not form a perfect system, it is possiljle that the realm of sensations is )iot exhausted by our senses but that other animal souls may exist with entirely different, although, of course, to us unkmtwu. forms of sensation. i?-). The duration of sensation can be roughly com- pared, in general, to that of the nerve process which OUTLINES OF PSYCHOLOGY. 11 ])rodnces it. For we find, niider ordinary cireumsiaiices, that it never continues lon^jfer than the duration of the external irritation, unless the latter leaves behind en- during effects Avithout or within us. which themselves constitute the stimulus for new sen>ations. Strictly speaknig. however, an excitement of the nerve, once produced, cannot cease of itself l)ut must be inter- rupted by active opposition. This is usually furnished during health by the continuous activity of the nutrit- ive process, by means of which the normal and indifferent condition of the nerves is restored and they thus ju-e- pared to impartially receive new impressions. Very generally, however, not only when the irrita- tion is very severe but particularly in the case of the sense of sight, the process may not be rapid enough. Then we have continuous or sometimes periodical exci- tations corresponding to the well-known illusions. /. e., actual sensations, which, if active enough, prevent the sense from receiving new impressions. An exam))le of this is furnished l)y the Ijrilliant figures produced by looking at the sun. §6. Every day experience, as. for example, observa- tion of an approaching light or of an expiring sound, shows that we are, in general, very sensitive to small differences in the intensity of the .•-timuli of sense. They are. however, only ]ierceived as more or les>^ in- tense and the moment never comes when we can affirm, 12 OUTLINES OF PSYCHOLOGY. from the evidence furnished by the impression simpl}^ that one light is half as bright or one sound half as loud as another. This circumstance prevents us from finding, by the most direct method, the exact law governing the de- pendence of the sensation upon the intensity of the stimulus. We can, indeed, easily arrange a series of irritations which admit of an accurate measurement of their var- ious intensities but we can not, by means of the obser- vation of the intensity of our own sensation corres- ponding to them, refer to each its value in nu^ubers. We can not, therefore, derive from the comparison of these two sets of values the general law which suffices for all. We are, therefore, driven to the following cir- cumlocution, depending on the fortunate circumstance that we are at least able to judge with a high degree of accuracy and certainty of the likeness of two sensa- tions. According to the fundamental experiments of Ernst Heinrich Weber (article " Sense of touch and sensation" in R. AVagner's Dictiominj of Flnjaioloyy, vol. Ill, part 2. ) which have since been confirmed and extended hy many others, tAvo similar excitements, when they begin to vary, do not produce two evidently dis- tinguishable (instead of identical) sensations until their intensities stand in a definite geometric ratio. This ratio remains the same for one and the same sense, within the limits, of course, of irritations so small as OUTLINES OF PSYCHOLOGY. 13 not to awaken the nerve and so violent as to disturb the function. On the other hand it is different for differ- ent senses, approaching about 3 : 4 for the hearing and simple feeling of pressure upon the skin; 15 : 16 for the latter when supplemented by muscular sensa- tion in lifting; 100 : 101 for sensations of light. §7. The dependence of our capacity for distinguish- ing impressions upon the ratio of the intensity of the irritation, which has been derived from observation, is embodied in Weber's Latr. It does not explain, however, in what way the ratio of the intensity of the irritation really prepares us to distinguish impressions. It does not explain, namely, whether the variations in the intensity of the irritations produce a noticable difference in the /;?/('y/s/f// of sensations, these otherwise remaining the same, or whether they produce sensations quaUfdiirehj different, and which are in this way dis- tinguished. In itself, every sensation is a single indivisible act. To separate in thought as distinct elements the qualitative content and the intensity with which it is perceived is indubitably permissible in so far as the immediate im- pression, with regard to which we can alone decide, agrees with it. This is, for example, the case with sounds. Here we may really convince ourselves that a sound of definite pitch and timln-e may become louder 14 OUTLIXKS « F PSYCHOLOGY. or fiiinter without altering its character on this account. On the other haiiiL it is quite ([ueistionable if the sen- sation of a heavy ])ressure is tlie same as that of a lighter one, or if the taste of a concentrated acid is really the same taste as that of a more dilute acid of the same kind. Still more reluctant are we to consider the sensation of cold as sini})ly that of a feel)ler heat. Both art', rather. o])p()site poles, although the agencies producing them are similar processes. Finally, various intensities of light have really vari- ous colors; a less lu'illiant .white is not simply pale white, but it has become gray, and this gray, as well as black, cannot be considered as simply a feebler sensation of white. These ])oints have been overlooked hitherto and not disposed of. The following discussion depends upon the assump- tion, which, although unjiroven. may be correct, that sensations are distinguished because their intensities vary accdrding to a detinite scale. §8. It must be first remembered that for each sense a certain small irritation is necessaiy before a sensation can result. Naturally, in order to explain this circum- stance, which is lint at all self-evident, a resistance of some sort must be assumed l)y reason of which a very small irritation is })revented from aifecting the mind. Where this resistance is offered is not known. It is farther assumed that the passage from complete OUTLINES OF PSYCHOLOGY, 15 identity or imperceptible difference in two impressions to a difference jnst distinguishable is always one and the same constant increment of the sensation ( /. c. of the second impression as compared to the firsts and that the minuteness of the distinction, may. therefore, be employed as a scale for measuring the intensity of the sensation. It may be inquired, how must the irritation increase so that the passage from one value of it to another may always produce a constant increment in the inten- sity of sensation. According to the experiments refer- red to the answer is this: In order that the intensity of the sensation may increase l)y a constant difference. /. e.. in arithmetical ratio, the intensity of the irritation must l)e increased much more rapid!}'. /. ('..in geometri- cal ratio: or. the relation of the first to the second is comparable to that of a logarithm to the number of which it is the logarithm: more simply expressed, sen- sation belongs to that class of activities which rise in intensity with greater difficulty the more intense the ac- tivity they are already exerting. The following questions remain to answer: — 1. Why this peculiar relation occurs at all, and why the sensation and the irritation are not, the rather, di- rectly ])roportional. which would seem more mitural? None of the theories offered is satisfactory, but the most ])lausil)le assumption is that, in the transformation of 16 OUTLINKS OF PSYCHOLOGY. the external irritation, something or other takes place which proceeds slower as the irritation increases. 2. But why is it that all impressions are not distin- guished — that, for example, a weight 3 must increase to 4 in order to produce an additional sensation of pressure and none is produced by 3^, 3^, or 3| ? Certain arrange- ments can be easily thought of by which this discontin- uity in the series of sensations could be produced but it is not in the least known where or how in the body or soul such arrangements are situated. Both these riddles are quite unsolved. (Comp. G. Tit. FecJtiier, Elements of Psycho-physics, Leipzig, 1860. G. E. Muellef, Fouiulation of Psycho-ph3'sics, Berlin, 1878.) §9. It may, perhaps, be claimed that a state of rest or an entirely unvaried excitement is never the immediate occasion of sensation, hwi that the passage from one condition to another is always necessary. From this it would follow that sensations which may continue to us for a long time, for example, the seeing of a light or the hearing of a sound, must be based on series of single im- pulses with inter veriing })auses so that here also a fre- quent repetition of alterations between excitement and a state of rest would occur. In the case of sensations of light and sound this can be proven. Hei'e even every single flash of light and OUTLINES OF PSYCHOLOGY. 17 every shortest sound consists of a considerable number of discrete impulses which are transferred to the organs of sense. In the case of the other senses this evidence is wanting. If it be said that all processes of stimulation which are to ])roduce sensations must have the form of oscill- ations between two opposite conditions, it, at least, must not be understood that the sensation consists in the enumeration of these impulses. They can only be regard- ed simply as the actual conditions upon which the origin of sensation in an unknown way depends. In the con- tent of sensation itself — in redness or warmth — we dis- cover no motion whatever and still less the numljer of the oscillations by reason of which it becomes the cause of sensation. §10. If an excitement a. which is ordinarily produced by the operation of an external irritant and which i^ fol- lowed by the sensation A. be exceptionall}^ produced by an irritant arising within the body then the same sensa- tion A will folloAv; this is called suhjedire sensaiion. Common examples are the ringing in the ear, flashes of light in the eye, and fever chills and heat. In connection Avith this stands the theory of the specijic eneygij of the nerve according to which each in- dividual sensory nerve always produces the same sensa- tion however it ma}^ be irritated. If it were so, it would not l)e strange, for every connected system of parts 18 OUTLINES OF PSYCHOLOGY. which is disturbed but not destroyed reacts in attempts to regain its equilibrium, the form of which re-action, depending upon its own structure and its inherent ac- tive forces, is not altered 1)V the diversity of thedistiirl)- ing irritants. But, in that case, since this attempt in one nerve is distinguishable from that in every other, each nerve must have its own peculiar structure, a con- dition which we have not. as yet. discovered. There are no facts, however, which require to be thus explained. vVe simply know that light stimuli, blows, pressure and the passage of electrical currents through the eye waken sensations of light, and. jterhaps. that blows and electricity produce sensations of sound, and the latter of taste. Now a motion of the ponderable portion of the elastic globe of the eye can hardly take place as the result of a blow without its being followed by a translation of a part of it into motions of the ether within it. thus producing light waves whicli would constitute as suffic- ient an irritant to affect the optic nerve as if they came from without. In like manner, a blow may impart to tense mem- branes and organs vibrations which then constitute normal stimuli to the auditory nerve equally with sound waves from without. Finally, the electric current produces certain chemical decompositions of the fluids of the mouth in which are to be found sufficient irritants to affect the trustatorv nerve. OUTLINES OF PSYCHOLOGY. 19 Hence it may be maiiitaineil that in (jrder that the nerve should reach the condition a which is followed by the sensation A a definite adequate irritation is jiec- essary, but very many inadequate irritants exist which subdivide in their operation into various components, one of which may be an irritant adequate to produce the sensation A, others being perceived at the same time in other sensations, as, for example, the simultan- eous feeling of pain in case of a l>low. §11. The operation of the external irritation is not as simple as formerly supposed: waves of light not act- ing, for example, directly upon the optic nerves to awaken according to their eonstitiition all possible color and light sensations. There are found in the eye pecu- liarly constructed layers, as yet not well understood (rod and spindle layers) which appear to be designed to translate the light waves entering them into chemical changes in a peculiar substance (optic-purple) which then act as irritants upon the oj)tic nerve. In the skin and tongue we likewise find peculiar tactile and gusta- tory organs, which, in some unknown way^ are sup- posed to give to the irritati(Ui the detinite character nec- essary to affect the nerves contained in them. In the ear we find something analogous, although here the simpler arrangement seems to prevail, each single nerve-fibre being receptive only to a single tone. The entire expanse of the tiltres (in the organ of Corti) 20 OUTLINES OF PSYCHOLOGY. is thus like a piano and each thread receptive to only one rate of vibration. A similar hypothesis is in vogue as to the eye. Accord- ing to this theory there are three sorts of threads, of which each is irritated independently, and each is sensi- tive to one of the three fundamental colors — green, red, and violet. The other colors result from the simultaneous irritation of threads of the other sorts. This hypothesis is not invented gratuitously, but to ac- count for the phenomena of eoJor-hliiidness which are explained by it. It is necessary to explain, however, why a definite combination of simultaneous excitements can produce from red, green and violet, the other colors, as yellow, blue, and red, which, so far as the impressions of sensa- tion are concerned, seem not at all likely to be derived from them. §12. In one sense, a// sensatious are but sul)jective, /. e., only appearances in our consciousness which have nothing corresponding to them in the external world. Even in antiquity this truth was outlined, and modern physics tills out the ])icture. The external world is neither silent nor loud, neither l)right nor dai'k, but is as utterly incomparal)le to these as is sweetness to a line. Nothing is hapi)ening outside of our l)odies but motions of various sorts. Physiology often makes the untenaljle statement that OUTLINES OF PSYCHOLOGY. 21 sensations are simply apprehensicns of our OAvn condi- tion. All that goes on in the nerves while we are see- ing is not in the least perceived by us, and there is known no process in our sonls preceding the sensation so in- timately that it may be called an act of })erception of the sensation. It may be said, therefore, that sensa- tions are appearances within us which are, indeed, the results of external irritations, but are not strictly rep- resentations of them. The proofs upon which this theory rests^ all, admit of evasion. It may be still assumed that things are really red or sweet, but we cannot know them to be so except as they cause motions to operate upon us which cer- tainly are neither red nor sweet, but cause to arise in our minds the same redness and sweetness, as sensations, that really are peculiarities of things. The real proof is that such objective peculiarities are unthinkable- Wherein consists the brightness of a light which no one ever saAv, or the sound of a tone no one has heard is quite as impossible to say, as Avhat a toothache would be which no one ever had. It is, therefore, part of the very nature of colors, sounds, odors, etc., to be limited to a single jiosition and a single occasion. They can, namely, only exist in the consciousness of a soul, and then only when the sensa- tion is felt. CHAPTER SECOND. THE PROCESS OF CONCEPTION. §1. Concepts, in contrast to sensations, are those pic- tures of memory which are left in consciousness by earlier sensations. This agrees with our ordinary use of language: we conceive of the absent, which we do not perceive, but perceive the present which do not require to conceive of. Conception is peculiarly distinguished from sensa- tion. The concept of the brightest light does not gleam, of the loudest tone does not resound, of the acutest pain does not ache. In each case, however, the concept accurately represents the gleam, the sound and the pain which it does not really reproduce. §2. These pictures of memor}^ are not ahraijs pre- sent in consciousness in this form. They appear only now and then, but, when they do. in such a way that no external irritation is necessary for their re])roduc- tion. It follows that they were not entirely lost in the meantime, but must have transformed themselves into some conditions, which we cannot, of course, describe, but for which we may emjdoy the contradictory but convenient name. " unconscious concepts," to indicate OUTLINES OF PSYCHOLOGY. 28 that they are formed from concepts and, under proper circumstances, may again become concepts. The study of the process of conception must exphiin both these states. §3. The disappearance of concepts from the con- sciousness no one can observe; we can speak only upon the basis of decisions drawn from what we find in con- sciousness afterwards, and upon general principles. Two views stood opposed to each other. It was for- merly thought that the disappearance of concepts is quite natural, and that the opposite — memorij — requires explanation. Now. however, following the analogy of the physical law of inertia, it is thought necessary to explain forf/etfiii;/. because the continuance of an ex- cited condition is self-evident. This analogy is rather lame. It api)lies to the motions of bodies, but motion is only an alteration in external relations liy which the moved body does not suffer, because it is situated exactly as favorably in one place as the other, and has neither cause nor standard for putting forth a resistance to the motion. The soul, on the contrary, is placed in various internal conditions according as a. or b, or nothing is conceived. It is conceivable that it reacts against each of the impres- sions offered, and thus, without annihilating any of them may, perhaps, change them from conscious sen- sations into unconscious states. 24 OUTLINES OF PSYCHOLOGY. Even the principle of the unity of the soul, admissible as it is in itself — even this unity, which makes necessary the reflex action between the many conceptions, so that one must replace the other — does not lead us to the goal. For, if it be asked in what way the soul, in its unity, utilizes the plurality of concepts, the most reasonable assumption would be that all qualitatively diverse sen- sations or concepts are fused in a single homogeneous intermediate condition. Yet this is not the case, but the concepts, for exam- ple, of blue and yellow, or large and small^ when once originated in the consciousness as distinct, never mingle. It is also clear that all the higher spiritual products^ which consist chiefly of relations between different points which are to be compared, would be impossible if, in this fusing into a common condition, the divei'sit}" of the different points were lost. The following thoughts are suggested simply as hy- potheses which are not deducible from principles. §4. According to the analogy of physical mechanics, concejits might ])e considered as forces Avhich oper- ate upon each other according to the degree of their resistance and intensity. Both ]iarts of this hypoth- esis are difficult to support by experience. In regard, firstly, to the intensity, this notion is employable in the case of sensations, in as far as the greater per- ceived content is an effect of the greater activity of sen- OUTLINES OF PSYCHOLOGY. 25 satioi], or a more severe agitation or affection of the perceiving subject. But the simple concept of a bright light is no greater than that of a feeble shimmer, and that of thunder requires no greater effort than that of a slight noise. The conceiving activity seems then to permit of no distinction in intensity, but this must be found alone in the conceived content. Moreover, the more or less obscure concepts^ which we think we have of one and the same content, by no means produce a diverse intensity of the conception. Simple concepts Avhich seem obscure to us, as, for example, that of the taste of a rare fruit, we do not have at all. but simply know, from other sources, that the fruit has a taste. The greater the field within which a choice is possible between various tastes with- out reaching a decision, so much the more obscure ap- pears the concept of the real taste which we are seeking but do not possess. CompJex concepts, such as pictures of external objects or scientific formulae, are not obscure because the entire content becomes gradually fainter. Ijut because it be- comes discontinuous. Single portions drop out entirely, but, particularly, the definite relations in which the re- maining constituents stand to each other are forgotten. The greater the number of the possible connections between which one hesitates, the greater the. so-called, obscurity of the concept. On the other hand, as soon 20 OUTLINES OF PSYCHOLOGY. as a concept is thought complete in all its parts and connections, it is not possible to conceive it more or less vividly. The increase in clearness v^hich seems to result from the association by research with the con- cept, say of a triangle, of the many other thoughts un- kno^vn to the beginner, is ])ut apparent. §5 The second of the notions employed, that of re- sistence, awakens the question whether it refers to the conteid of the concept, or to the activity by which it is conceived. These are not identical. Concepts are never that which they represent, that of red is not red. that of a triangle is no triangle, that of passion is not a passionate concept. If two conceived contents oppose one another, as right and left, ])lus and minus, black and white, it does not, in the least, follow tliat the conceiving activities Avhich produced them are also opposed, and so, according to the analogy of opposed physical motion, would tend to neutralize each other. §6. The notions of intensity and reaction would onl}^ be applicable to the founding of a system of psychical mechanics if they could be referred to the conceiving activity. This is not the case. It could merely be accepted as a fact, if the intensity and reaction of conceived con- tents were the causes of the alterations of conception. OUTLINES OF PSYCHOLOGY. 27 Experience does not confirm this; conceptions of laro-er contents by no means displace those of smaller. On the contrary, the latter are sometimes in a position to sup- press even the sensations of external irritation. Now concepts never mter the soul without doing something else: connected with every impression is that which is conceived to be its result, and also a sense of the value which it has for the physical and sjiiritual well-being of the one perceiving. These feelings of pleasure and displeasure are just as capable of gradual diminution as the simple conception is incapable of it. This feeling of participation is sus- ceptible to great variations dependant upon variations in the state of mind, and according to the amount of this feeling of participation, or, briefly stated, according to the amount of interest which a concept, for various reasons, excites in the soul at each instant, it operates with greater or less force to suppress other concepts. It is in this, rather than any inherent peculiarity which the concept has. that what we call the power of the concept consists. §7. The second question was, how do concepts return into consciousness? With regard to this, it is simply known that a concept, b, very frequently returns if an- other, a, be produced in consciousness. As, however, not any b appears as a result of the jiresence of any a we please, there must be a more in- 28 OUTLINES OF PSYCHOLOGY. timate connection between those which reproduce each other than exists between those which do not so rejjro- duce each other. This connection is called «ss(»ciafio)i -;-a sim))le name which does not in the least express in what the connection consists. Likewise is repro(//(c- tion a simple name for the fact that a o^iven a recalls into consciousness b, which is associated with it. Nevertheless, the conditions under which Ijoth assoc- iation and reproducticni actually take ]dace may be studied. The two primary classes which are usually first men- tioned, /. e., re})roduction, on the one hand, of likes by like, and, on the other, of opposites by opposed concepts, are not readily supported by experience. For it cannot be said that a sound or color recalls more vividly all other sounds and colors than some other ciuiceids. If, on the other hand, opposites remind of each other, as darkness of light, night of day. plus of minus; the reason is not their opposition alone, but the si)ecial importance which these have for oui- life or its activities, so that we are thus reminded of the one by the other. But the third and fourth cases, the reproduction of parts of bodies occupying space b}' other parts and. on the other hand, the mutual reproduction of the parts of a successive whole, as. for example, a melody in its original order, do certainly occur. Examples are unnecessary. Neither does it seem nec- essary to refer the third case, as is often done, back to OUTLINES OF PSYCHOLOGY. 29 the fourth, because, it is said, the perception of a sim- ultaneous whole takes place in a successive manner, the eve requiring to run over the whole and thus gradually perceiving the connection of each several part with the next. We do, indeed, form accurate images only in this way, but it is not to l)e denied that an instantaneous glance may form images of which the single parts are capable of reproducing each other. The facts may, therefore, be thus summarized: — Every pair of concepts, whatever their content, assoc- iate themselves whenever they are produced simultan- eously or one immediately following the other (,. e., without intermediate ones ). To this case may be re- ferred without further argument, the special ease with Avhich a number of concepts may be repeated in their order but not out of it. If, finally, 'iHiDiediate reproductiou be given as a spec- ial case, comprising instances where the concept or sen- sation a is again awakened by the influence of a new irritation which produces the same a, it must be re- membered that the second a could not be recognized as a repefif/oii of the first if they were really both ident- ical. The first one. however, which is thus awaked by the second, now reproduces, on its part, those associated cii- cumstances under which it was previously experienced, and these are different from those of the present moment. The recognition of the original a is, there- 80 Ol'TLINKS OF PSYCHOLOGY. fore, dependent upon mediated reproduction. /. e., of other concepts through the agency of a. §8, Most concepts, in the course of a lifetime, assoc- iate themselves in the same way with many others. If, therefore, a definite f is again distinguished in con- sciousness, it is quite uncertain Avhich of the many others, g, h, i, or k, with which it was formerly assoc- iated, may now l»e reproduced. The basis for tlie decision in favor of any one lies partly in the course which tlieconcei)ts prior to f have taken, with which g, h, i, and k may not eciually agree; partly in our mood or the humor produced each moment by the activity or restraints of our being; jjartly. finally, in the peculiar conditions of the physical life, whicl] we will here omit entirely. l)ut of which we Avill speak further on. These views cari only Ije tarried out in a general way. it being imi)<;)ssible to Ijuse theories upon them which can be carried into details, and equally impossible in an individual case t<) discover the causes which have really jtroduced the seemingly ca])ricious flow of our thought. CHAPTER THIRD. RELATIVE KNOWLEDGE AND ATTENTION. §1. Up to this time we have spoken of the rehitions and alterations in conceptions. In onr inner life, how- ever, there . is, besides these elements, a conception of these relations and vicissitndes. These two things are quite different. We know that when the concept of 1)lue and red ap- pear at once within us, they, by ^lo means combine t(j produce violet. If this Avere the case, the result would be a simple concept taking the ])lace of the others, and a comparison of the two would be inade impossible by their disappearance. Every comparison — in general, every relation between two elements (in this case red and blue) — is evidence that both the factors are distinct, and that a conceiving activity passes from the one, a, to the othei', and that this alteration which is experienced in passing froui the conce})t of a to that of b is itself in consciousness. Such an activity we exert when we compare red with blue, and the result is a new concept of qualitative sim- ilarity which we accord to )x)th. If a strong and a weak light are perceived at once, the result is not the sensation of a single light equaling 32 OUTLINES OF PSYCHOLOGY. the sum of them both, Ijut they remain distinct, and in passing again from one to the other we become con- scious of another qiiantitive alteration of our condition, i. e., the simple perception of more or less of the same impression. Finally, if two identical impressions have appeared within us they do not unite to form a third, but. as we compare them, as above, and do not Ijecome conscious during the transition of an alteration in the concept, the new conception of equalit}" arises. §2. It is inijiortant to explain that all these new con- cepts, which we consider as of a higher order, do not appear as resultants of a mere reciprocation of the orig- inal simple concepts in the same way that in mechanics a third movement results from the uni(ni of two others. This analogy does not hold good at all in the spiritual realm. The two impressions, a and b, are rather to be considered as stimuli which operate upon the peculiar and unit nature of a conceiving subject, and. in this, give rise to the reactionary activity through which new concepts, for example, that of similarity, identity, con- trariety, etc.. result, which would not ])e produced by a simi)le conilnned activity of the separate impressions Avithout the stimulation of this new spiritual activity. §3. In the same wa}' as these new concept are formed, all of what we call general notions are jn-oduced. OUTLINES OF PSYCHOLOGY. 33 It is onstonuiry to assume that dissimilar coustitneiits of compared concepts neutralize each other by their contradiction, but the remaining simtlar components constitute directly the abstract i)art. However, the single exani])les, out of which we construct a general notion, are not destroyed in the process, but their con- cepts remain along with the general notion which, as ti new product, simply I'efers to these. Moreover, the general notion never forms a permanent picture which may be conceived (jf in the same conspicuous way as the single examples from which it is composed. " Color in general "' can not be imaged to the mind — it does not look green or red — it does uot "look" at all, and just so the concept "animal" ]iroduces no distinct image like the concept of a single species. All such general notions are not, therefore. ])rodurts of the comlnned operation of mauy single concepts, for tliev would then have the same (diaracter as their components. The names with which we designate them (such as the word color) are sim])ly conveniences for the conception of a grouj) of single impressions, but with the accessory idea that they refer not to them, but to the common features contained in them, wliicli cannot, however. l)e separated from them as a similar coucejit. 5^1. r]ioii this fact dejiends the various narrower and broader meanings of the w(n'd c'liisi-in/i^iiirss. ft often ha]ipensthat we perceive the plui'ality of tdements. but le to become conscions of them liiter, even after the sensuous impres- sion is past. It follows that these impressions were by no means ontside of consciousness, otherwise we conld not remember them afterwards. But the faculty of comparison, which enumerates and conceives of the re- lations actually existing between them n-as not exerted. It is seen from this that the two o[)ei-ations are sep- arable. The process of comparison, as the higher, can not 1)6 employed without the sim])le perception of the sensa- tion, but the lower is not necessarily accom]ianied by the higher. Common ex})erience shows that tliere are many cir- cumstances whicli prevent the apjiearance of this higher activity. In many emotions we hear the sounds l)ut do not understand the words: or. uiulerstand the words but not the signiiicance which they have for us. Even l)odily and some little understood conditions cause that the simple sensation of impressions persist while neither their external nor internal connection reaches our con- sciousness (mind-blindness ). §5. What we have above mentioned is nothing, in reality, but a series of various degrees of I'ttoifion. This was formerly considered as an activity of the soul which, like a departing and approaching light, illumin- OUTLINES OF PSYCHOLOGY. 35 ates, more or less brilliantly, the impression, while it is of itself unperceived. Later this idea of an activity was entirely rejected (Herbart). and the statement was made that the fact that Ave are attentive to something signifies simply that the concept of this something rises in our consciousness liy its own intensity. We cannot accept the latter assumption, nor can we admit the statement that attention is sim])ly a more in- tense illumination of the content. We attain anything through the agenc}' of attention only when the con- ceived content affords opportunity for the operation of our faculty of reference and comparison. Even a simple content is compared l^y us at least with other simple contents, or Avith itself in different moments of its duration. We learn from this that the mere obsenrifio)! of the content, intense as it may be, amounts to nothing. It is plain, fiually, that this com- parison of one content with another may be carried to any desirable extent. Various stages may thus, indeed, be distinguished in the consciousness according as simply the thing itself and its oAvn nature is conceived; or its connection with others; or. finally, its significance and importance to our })ersonal life. CHAPTER FOURTH. THE INTUITIONS OF SPACE. ^1. Metiiphysics riiises the iri'itants upon tlie retina is insured cannot he in vain. Certainly it is true that an ini})ression is not perceiveil at a definite [toiut hecause it is at that point, luit it is certain that it mi<'"ht affect the soul far differently in this jiosition than if it were ])ro- duced in any other point. Now we will imagine the folhiwin*^" arrang'enient: Each color-iini)ression R, for example red, produces the same sensation of redness whenever it affects the retina. But along' with this in eai h jioint. a, b, C, etc.. a certain accessory impression. A, 14, C, etc., is produced which is indejiendent of the nature of the color seen, and simplv dejiends u])on the peculiarities of the irritated s}»ot. In this manner a local impression is associated with each color-impression, so that RA will indicate a red reaction at the j)oint a, RH a red reaction at the point b. These associated ini])ressions become indices which enahle the soul to refer the same sensation red now to one and now to another place, or even simult- aneously to Vf-rious ])oints in the space ])erceived hy it. In order that this may occur in an orderly manner these accessory impressions must lie quite distinct from the principal ones, and not interfere with them. But they must not only l)e like in kind, but definite mem- bers of a series, or a svstem of series, so that each ini- 0UTL1KE8 OF PSYCHOLOGY. 41 pression R may be able, by its local index, to distinguish, not simply a particular, but an absolutely definite place from all others. §7. This is the theory of locaJ iiidiecs. The funda- mental idea is that all diversities in extension, and relations between impressions upon the retina must be translated into corresponding unextended but simply intensive relations between the impressions concurring Avithout extension in the soul. These are not reflected in actually discrete impressions, but there results simply a concept of snch a redistribution. U]i to this point we hold this })rinciple to be neces- sarily valid. On the other hand, only hypotheses are, available to answer the question, in what these impres- sions consist which are assumed as accessory to the sense of sight. We suggest as follows: If a bright light fall upon the sides of the retina, where, as is well- known, the sensitiveness to impressions is duller than in the middle, there results a rotation of the eye so that the more sensitive part of the retina becomes the re- ceptive organ. This we call casting a glance upon that light. This motion takes place involuntarily, origin- ally without our realizing its purpose, and always Avithout our consciousness of the means by Avhich it is efEected. We may, therefore, include it among the so-called reflex motions which result from the excitement of a 42 OUTLINES OF PSYCHOLOGY. nerve, otherwise sensory in function, to transmit a stimulus resulting in a definite motion: this taking place by means of existing anatomical connections, in a way entirely mechanical. Avithout farther agency of the mind. Now in order to jn'oduce such a rotation of the eye. suited to the purpose mentioned, each individual part of the retina must, when irritated, produce a degree and direction of this rotation peculiar to it alone. At the same time, however, all these rotations would be quite analogous motions and members of a series graduated according to their magnitude and direction. • §8. The application of this theory (many minor points aside) is as follows: — If a bright light fall upon a point P of a retina which has, as yet, had no sensation of light, there re- sults, by virtue of the connection of nervous processes, such a rotation of the eye that, instead of P, the point E, where the impressions are most vivid, is sul)mitted to the irritation of the light. During the rotation of the eye through the arc P E, the soul is conscious of its position at each instant, a feeling similar to that by Avhich we are informed of the position of our memljers in the dark. The arc P E, therefore, cor- responds to a series of constantly changing sensations of position, the first member of which we may also call P and the last E. Now, when in a second instance the OUTLINES OF PSYCHOLOGY. 43 point P is affected by light, the result is not onh^ arep- ititon of the rotation P E, hut the very first meniher. P, of the series of sensations of positions reproduces the Avhole associated series P E, and this series of concepts is independent of the actual rotation throuoh the arc PE. The same thing; would take place in another ]K)int Q, except that the arc Q E, the series of sensations of position Q E, and the introductory nieniljer Q would have different values. Finally, if it should happen that both thefpoints P and Q were irritated to the same degree, and the arcs P and E and Q E were siinilar. l)ut opposed to each other the actual rotation P E and Q E eould not take place, nevertheless, the irritation of the points P and Q would not be inoperative. Each would reproduce the series of sensations of position belonging to it, P E or Q E. Therefore, although the eye does not move, the excitement of the points P and Q associates with them the concepts of the magnitude and peculiar- ities of the series of changes which would be experi- enced by the consciousness in the act of transferring the irritations to the point of the eye where they would be most clearly seen, or, in ordinary parlance, in the act of casting a glance. We now nniy state that in the act of seeing a thing to the right or left of a given line of view we simply become conscious of the anujunt of effort necessary to cause them to coincide with that line. 44 OUTLINED OF F.SY('HOLOGY. §9, In this discussion we have simply explained the relative position of the individual colored points in the held of view. This whole inia<>e would, however, have no position in any greater space, indeed, no concept of such space would he present. We ohtain the image of a place at first through the agency of the eye^ the opening and closing of which ( of which jtrocesses we are otherwise C(mscious) determine its existence and non-existence. The visible world is before the eyes, and whatever is behind not only does not exist for us, but we do not yet know that there is such thing as •' behind us.'' Motions of the "body extend our knowledge. If the field view in a certain position contains the images a, b, and c, passing from left to right, and we then revolve upon the axis of the body toward the right, a disappears. ))ut on the right d is added. A\'e perceive in succession the images of b c (I, c d e, d e f x y z, y z a, z a b, a b c. As a result of a recurrence of the original images we have two thoughts; first, that the visible objective world is in the form of a continuous extension all about us, and, secondly, that the alterations in our condition, of which we are apprized during the revolution by the varying sensations of ])osition. depend upon changes in our relations to this quiescent external world, i. e., upon motion on our ]>art. It is easy to see that out of the concept of a continiu)us horizon the concept of spherical extension may Ije derived by various revolu- tions in other directions. OUTLIKES OF PSYCHOLUGY. 45 §10. This spherical surface woiikl possess only super- ficial extension, and no hint of a third dimension would be given. The concept that such a thing as a third dimension of space exists can lujt spring up spontane- ously, Init must be derived from experience, which comes of passing about among the visible objects. From the manifold variations in the various images we reach the impression, in a way tedious to describe, but easy to imagine, that every line in the original im- age is the beginning of new surfaces, which do not coin- cide with those first seen. l)ut lie at a greater or less dis- tance from them in s]iace which extends in all directions. We have later to i-onsidcr the question how we esti- mate the distances in this third dimension of space. §11. The crossing of the rays of light in the small opening of the pupil causes the image of upper points in an ol>ject to lie l)elo\v. aud those of lower points above, upon the retina, so that the image, as a whole, is re- versed. But it is only prejudice which makes it seem en- igmatical that we do uot see tilings upside down on this account. Like every geouietrical peculiarity of the im- age this relative position is utterly lost in the trans- mission into consciousness, and the position in which a thing is seen is not at all predicated l)y the position of tlie image. But in order that we may ascribe position at all to objects — in order, in other words, that the expressions 4() OUTLINKS OF PSYCHOLOGY. above, below, upright and inverted, may have a mean- ing, it is necessary to have a concept of space v^^hich IS entirely indeiiendent of the sensations of vision — a concept of space in which the entire contents of the fiekl of vision may be arranged, and iix which, above and l)elow are two qualitatively opposite, and conse- quently not confusible directions. The muscular sense furnishes such a concept. Below is the point towards which gravity tends, above is its opposite. Both these directions are clearly disting- uished by immediate sensation, so that we are never de- ceived as to the position of onr l)(»dy in the dark. We call objects upright when the lower part of the object is seen by the same motion of the eye by which we see parts of our person Avhieh our muscular sense assures us are below, and the upper parts of the object in like manner with the same motions which l)ring up- parts of the body into view. This agreement is brought about by the inverted pos- ition of the image on the retina. In an eye in which the sensitive surfaces were in front of the axis of rota- tion, but with the greatest sensitiveness in the centre of the retina, the same result would require the image to be positive. §12. It is not possible to explain satisfactorily why we see singly, although having two eyes. It does not indeed always happen, but two impressions must fall OUTLINES OF PSYCHOLOGY. 47 exactly upon two definite points, in order to comlnne. Naturally, we might explain that the two points which correspond must produce identical local indices which can not be distinguished, but we can not demon- strate how this postulate is satisfied. In like manner physiology contents itself Avith simple names. Points on the two retinas which produce simple im- pressions are called identical points, and those which furnish double impressions are called iton-klentical. §13. We naturally refer irritations of the skin at once to those }ioints of the skin Avhere we see them op- erate, l)ut in case of a repetition when we cannot see them, the memory does not assist in the least, for most of the ordinary irritants have affected all possible parts of the skin, and might be referred to one point as read- ily as another. In order to correctly localize them, we must be in- formed anew at each moment where they belong, that is to say, some accessory impression must be associated with each primary impression (of impact, pressure, heat, or cold) and independent of it. l)ut dependent upon the point irritated. The skin is able to give rise to such local indices, for, on account of the continuousness of the skin, no single point can be irritated without a displacement, tearing, stretching or vibration of the adjacent parts. More- over as the skin possesses, at different points, different 48 Ol'TLINES OF PSYCHOLOGY. thickness, various elasticity or moveableiiess — passing now over firm surfaces of bone, now over the fleshv muscles, and now over cavities — and, as these relations vary with the varying positions of the members, it fol- lows that the sum of the accessory influences about one irritated point would be different from those groujjed about another. These influences when received by the teruiini of the nerves, and apprehended by conscious- ness, may cause the indescri])able sensation by means of which we distinguish a touch at one ])oint from one at another. Ft can not be said, however, that every point of the skin has a peculiar local index. The experiments of E. H. Weber show that on the margins of the lips, the end of the tongue, and the ends of the fingers, two })oints of contact (with dividers) can be distinguished whe-n only one half a line a])art. while there are places on the arm^, lejects. for exam])le mountains and water surfaces, leave no natural scale, so that only the OUTLINES OF PSYCHOLOGY. 53 apparent size is given, we can only arrive at the real size and distance by dividing it into parts which we esti- mate according to their relations to the apparent size of a known object contained in them. A very important means, linally, is furnished by ]iarallax, i. ?., the amount of displacement of the image of the object C, upon a fixed background. P, Q, R, if viewed from both ends, A and 15 of a line, A B. This is greater for a nearer and less for a more distant ()1)ject. We use this method daily by fixing an oliject in one eye and then the other, or moving the head from left to right, or walking intentionally to iind fro. Science has made great use of this l)y carefully per- forming the same ex])eriment with the assistance of fine instruments for measurement. §3. The comparison of sensuous (pialities (colors, sounds, tastes, degrees of warmth) affords a certain quantitative measure of the impression, be it intensity or extension in si:)ace or duration of time. It demands, moreover, that the testing organ be exactly the same in order that the various local indices shall not modify the impressions of different organs. A person does not test the warmth of two vessels of water simultaneously with two fingers, but successively with the same, etc.- At the same time the other breakers must be avoided — that of allowing too great a, time to intervene to leave both impressions vivid in consciousness, or too short a time, 54 OUTLINES OF PSYCHOLOGY. 30 that the secondary effects of the first interfere witli the second impression. These secondary effects are of two sorts. If they are strong and fresh, they obscure the second impression. l)ut very often, and in the cases of different senses, it happens that the nerve which has been for along time subject to the same excitement, after this has ceased, spontaneously assumes another sort of excitement, through wliich it passes again to its state of equilibrium. And this counter excitement produces sensations, as, for example, an eye long effected by green, red, or yellow sees afterwards the compliment- ary colors — red. green, and violet. These contrasting sen- sations appear in the case of ordinary and muscular sensation as well. §t. We consider a l)ody to l)e in motion if its image moves over the retina, and tliis appearance not only takes place if we experience a passive motion (as in riding on shipboard) but, also, when we are conscious of our motion and convinced that the objects which we are passing are stationary. Naturally, the apparent motion of objects is the opposite of our own motion. The well-known revolving motion which occurs after spinning about for some time and suddenh' becoming stationary appears to be caused by an unconscious move- ment of the eyes in the direction previously pursued by the body. Tnis motion, when it reaches the corner of the eyes, is instantly reversed but to l)egin over again. OUTLINES OF PSYCHOLOGY. 55 thus the same objects pass by continually without in- termission. §5. If any object, as, for example, a staff, is brought into loose contact with the body, say the hand, in such a way that change of position is possible, a new and peculiar combination of sensations of pressure on the different fingers, for example, is produced. Out of each combination we form, from earlier experi- encC; a concept of the position which the object (as the staff) then occupies. If now. the staff be brought in contact with an exter- nal object, and if it meets the same resistance in all its positions and this pressure acts through the staff upon the hand, we not only transfer the position of this resistance to the common intersecting point of all these positions, l)ut we think we feel it immediately and clearly at the place where it is offered, just as if the staff were endowed with sensation as much as the sur- face of the hand on which its other end rests. This feeling of double coiifacf, which has innumer- able examples, produces a peculiar vividness in our con- ceptions of external objects. It serves, first of all, to make possible the profitable use of many tools, as, for example, the probe, knife, fork, pen, etc. By means of it we seem to perceive the resistences or obstacles to these instruments in loco, and are able to apply the proper corrective instantaneously. 56 OUTLINFS OF PSYCHOLOGY. It teaches us, further more, of many of tlie peculiar- ities of things, for example, of the length of a balanced stick, or the breadth of a ladder rung, or the length of a thread attached to which a Ijall revolves abou^ the hand. Finally, it gives us the pleasant feeling of an exist- ence in spirit beyond the limits of our bodies, and this is the reason for the numerous delicate and peculiar prolongations or appendages of our body which usually serve as ornaments. [Note. — The further elaboration of this thought belongs to Physiology, but the force of the remark would be lost if cousidered to apply simply to the hair and nails, upon which we are much more dependent forour sen- sations of the o Iter world than we at tirst realize. The minute ridges and points found upon the skin of the hands setve in the same way that a probe does to acquaint us with the position of an object, for example, a needle, which otherwise we could only use aa roughly as we now do when the fingers are gloved.— C. L. H.] CHAPTER SIXTH. THE FEELINGS. [SUSCEPTIBILITIES] §1. We apply the term feelings exclusively to con- I ditions of pleasure or displeasure as contradistijiguished (^ from sensations, these being but indifferent perceptions of a content. We do not thereby assert that these two spiritual ac- tivities appear separately, it being more probable that primarily no concept is entirely indifferent, but, rather that the feelings of pleasure or displeasure inhering in them only escape our attention because, in adult life, the sense and significance which the impressions have for our sphere of existence have become more import- ant to us than the consideration of the impression itself. f' We conclude, therefore, that, as notions, sensation and feeling, although always connected, are quite dis- tinct efforts, and not derivalile the one from the other. Not any sort of a relation between various simultan- eous sensations or conditions produces of itself , an effect upon the sensibilities, but it is necessary, in order to produce a feeling that this relation should be brought to bear upon the soul, producing a reactionary activity of a faculty not previously included, ;. ^., a feeling. 58 OUTLIX£« OF PSYCHOLOGY. §8. A natural though undemonstrable inference, and a reasonable hypothesis is that feelings result from, and, at the same time, indicate the agreement or disagree- ment between the excitements produced within us and the conditions of the continuance of our well-being. Pleasure would then be the result of the stimulation of our natural faculties within the limf^-s of these condi- tions, and would increase with the intensity of the ex- citement: pain, on the other hand, would be induced by the fact that the excitement produced, partly on account of its intensity, and partly on account of its form (Avhich is generally overlooked), disagrees with these conditions. This does not imply that the soul first ol)- serves the excitement, then its rel.ition to these condi- tions, and, finally, decides, according to the opinion produced by these acts, to feel pleasure or pain, but, it is like sensation, say of a red color, simply the result of a series of processes in tlie nerves (although it does not enumerate them). In like manner, the feeling is only tlie last result of that strife or disagreement and only enters consciousness at the close of this unperceived process. §3. Pleasure and displeasure are general terms, which, thus comprehensively taken, do not designate a concrete thing, but every real pleasure or displeasure has its own specific character, and these cannot 1)e formed out of various portions of a general pleasure or OUTLINES OF PSYCHOLOGY. 59 pain any more than the various colors are produced by diiierent combinations of light and shade. Of the con- ditions under which the feelings in general, or definite forms of feelings arise, we know almost nothing. The first group which we can distinguish, the sen- siioits feelings, i. e., those which depend directly on sense irritations, are the more intense in the various senses the less these senses are adapted to discern them objectively. Colors and their contrasts produce simply satisfaction or dissatisfaction; dissonances of sounds disturb the hearer, personally ; pleasure and displeasure of taste and smell are much more intense; but only in the skin, Avhich itself furnishes but little information, and in the inner portions, which do not contribute at all to our know- ledge does this displeasure assume the character of actual pain. The advantage of this arrangement is evident, but the mechanical cause is unknown. §i. These less intense feelings of the higher senses lead to a second class, the d's^thetic feeJuigs, which are connected chiefly, Imt not exclusively, with the simultan- eous occurrejice of numerous impressions and, in the simplest cases, are actually dependent upon the simplic- ity or complexity in the relations which subsist between them. The real reason why this simplicity, for example, in concordant sounds, acts favorably upon us is unknown, 60 OUTLINES OF PSYCHOLOGY. for these relations, as such, are not, as a rule, perceived. The character of this aesthetic feeling of satisfaction or dissatisfaction can be distinguished from simple sen- suous comfort and discomfort in that the universal spirit within us and not our personal well-being is augmented or disturbed by these impressions. To these are aMed the ethical feelings, oi which we must speak because approbation or disapprobation is simply the expression of an importance or lack of it which Ave perceive only in our feelings, and on this account is quite distinct from a merely theoretical judgment con- cerning the truth or falsity of a postulate. §5. Further description of the susceptibilities is un- necessary, but, on the other hand, it is useful to dis- tinguish two conditions. That is frequently called feeling which should really be called affection, consisting, not in a quiet condition or mood of the soul, but in a motion which — as in anger or fear — produces disturbauces in the process of concep- tion, and also generally includes involuntary motions, partly simply gestures, and partly the beginning of ac- tions which arise from the given inducing cause if not controlled. In like manner we must distinguish sentiments, /. e., those apprehensions by the soul that certain contents of conception have always a definite value. Bravery or patriotism are not themselves simple feelings but causes OUTLINES OF PSYCHOLOGY. 61 out of which, according to the nature of circumstances, varying sorts of feelings may spring. §6. The notion "I" is usually defined as that of the simultaneous subject and object of consciousness. This definition, right as it is in itself, applies, nevertheless, to every being which participates in this general character of identity. When we speak of self-consciousness we do not mean the general form of activity which '' thou " and " he '" possess equally with " I.'" but we mean that knowledge by which we distinguish '' I " from " thou " and '■ he." It would be useless to affirm that " I " is the subject and object of ;;/y knowledge, but '' he" sub- ject and object of /eing their actual results. §5. A fourth class is formed by the iiiiifafive ittotions, as. for example, those made when the observer uncon- sciously imitates the blows of the boxers or of those playing at ten pins, and when the uneducated narrator imitates the motions descriljed. In this case it is the conception — and that of a definite motion — which, without further knowledge or volition, is translated spontiuieously into the motion. To this class belong most of our daily motions which we often even call acts. As soon as. at the conclusion of a train of thought, the conception of a motion founded upon it springs up and no resistaJice is offered it in any quarter, this concept passes over spontaneously into a motion without a distinct impulse of the will needing to be exerted or perceived. This applies particularly to acquired accomplishments, as of writing or piano-jtlaying, where the simple con- 66 OUTLINES OF PSYCHOLOGY. ception of the production of a^^oiind produces the nec- essary movements without any distinct conception of these motions lieing" developed in consciousness. §6 These considerations a})pear to constitute a dis- tinction between roJuuidyij and inroliintarti actions. In fact, they do not. Let our convictions of the nature of the will, to be developed later. l)e what it may. nothing; can be ascribed to it Init trill buj. It can only produce a result when a given change in the comlition of a motor nerve is combined with a given decision of the will, as the spiritual conditioning agent, by a natural law inde- ^})endent of it. When this is not the case the will ^_reinains a useless wish without result. An act is voluntary if the internal initiatory condi- tions from which an act springs are ai)proved. adopted, or controlled by the will when they have taken place. Invol- untary is every one which, although it, mechanically con- sidered, springs from the same initiatory ))oint and pro- ceeds in the same way, does not pxptM-iencc such ap))rovaLx The control of the will may l»e likened to our usi^ of the Alphal)et. VV^e can not devise new sounds or let- ters l)ut are limited to those which the organs of speech makes possible. l)ut we can combine these in endless variety. In like manner, the soul, in that it combines the initiatory conditions as it ])leases. may unite these ele- ments of corporeal origin — motions — into the most varied processes and thus affect the expression of its will. PART SFXOND. THE SOUL. (THEORETICAL PSYCHOLOGY. > CHAPTER FIRST. ON tup: p:xistex('E of the soul. §1. After this eiiiuiier;itiou of the iudividiuil elements of the inner life we inquire eoncernin<>" the nature of the subject in which they inhei'e or are made possible. Our iinal conclusion will be most simply developed by usino- those provisional views which we are accustomed to at first employ, and then ^'radually transforming them in order to adapt them to encounter difficulties with Avhich, in their earlier form, they could not cope. It must be remembered that everything' can not be said at once, and that only the final form which our view assumes is our ultiuiate conviction. §2. The permanent union of the spiritual life with the bodily, in which alone it becomes the object of observation, makes the attemjtt natural to re<4"ard it as simply a product of Ixnlily functions. However, it ivS an old discovery, recently newlv made, and by no means wantino; in truth, that out of all combinations of material conditions the origin of a spiritual condition of the soul never l)ecomes analytic- ally conceivable; or. more simply expressed, if we think of material elements in such a way as to predic- OUTLINES OF PSYCHOLOGY ate of them nothing which does not beh)ng to the notion of matter, if we simply conceive of them as entities in space which are moveal)lp and may call each otluM* into motion by their power: if we. tinall}'. imagine these motions of one or many elements as varied or combined as we please, there never comes a time when it is self- evident that the motions last )>rodnced may not longer remain motions but must be transformed iinto sensa- tions. A materialism, therefore, which assumed that a spiritual life could spring out of simply physical condi- tions or motions of bodily atoms would be an empty assumption, and. in this form, has hardly ever been advocated in earnest. The materialistic views which have really had adher- ents have proceeded from the premise that what we call matter is really better than it externally ajipears. It contains in itself the fundamental peculiarity out of which the spiritual conditions may develope just as well as physical predicates — extension, impenetral)ility. etc. — are developed out of another fundamental peculiarity. From this results the new attempt, out of the recip- rocal operations of these psychical elementary forces to elucidate all the elements of the spiritual life just as its bodily life is derived from the reciprocation of the physical elementary forces of its constituents. §3. This view, though not, on its face, improbable, is wrecked upon the fact that it is impossible to explain OUTLIXES OF PSY( HOLOGY. 73 by it the ori<roducing"it is no more seen, so, from a unifi- cation of the pluiality of psychical motions a ctmiplete unity of consciousness is formed, this would he an inac- curate expression of the analogy drawn from mechanics. It is. indeed, true that if two motions act u])0)i one and the same indivisi])le point or physical element, they produce a sim})le resultant. This resultant does not hang in the air, however, hut exists only as a condition of the simple element upon which the components oper- ated. Thus ccmipleted. this analogy does not lend to the result expected, hut l)ack to tin- ordinary view, namely, that these numerous elements, even if they possessed psychical capacities, could only proc.uce the unity of consciousness if there existed a single indivisible ele- ment n])()n whicli all their activities operate, and which must be so constituted as to concentrate all these impressions in its consciousness. ^•A. If Ave (1eiu»te by a, b,. . . .z the single bodily ele- ments which are assumed to )je both physical and psych- ical. the(piestion arises, Avhat result would be })roduced in a given time by the recijirocal action of one upon an- Ol'TMNKS OF I'SY('»OL()(JY other ? Tf they were fill similar and under like conditions it would hardly fail to happen that at the end of the time all would lie in a similar state. Z. If this state Z then were a consciousness it would he jtresent in our con- sciousness with tlu' same content, as many times expressed as thf uuuiher of elements acting u})on one another. On the other liaud a unitv of the consciou.s- ness, aside from this similarity of all the individual consciousnesses, would not result. In reality, the elements a, b,.---Z aiv not similar, but they certainly stand under various conditions in the structure of the organism, some of them, on account of their restricted nature aud unfavorable position, can a|)])rehend vividly but few oi)erations from without, others, superior and better situated, devel- ope a much richer consciousness of all the jtossible con- ditions of the others rei)resented in it. Which, now, out of the many dissimilar examjjles of consciousness is ours — that which we know by inner experience? We natur- ally wruld assume that it would be the consciousness of the most highly developed element of all — the central monad of our bodv. according to Leibniz. For we iind the alterations in our body most closely connected with the condition of the "■ I." aud very little goes on in it which we have reason to ascribe to the activity of other central points of consciousness. i^5. It f(dl(iws that we do not succeed in evading the OUTLINES OF PSYCHOLOGY. i'O view of the single and indivisible subject [soul] of our consciousness as a distinct part, while the other parts constitute a body, i. e., an aggregate of many elements which, taken separately, may be related in nature to the soul, l)ut in no instance are identical with it. but are dissimilar beings. This assumption, in itself conceivable, of a soul life in every bodily element remains quite useless for the explanation of our soul life, for we can not transfer ourselves into the condition of these elements. They have worth for us simply as they operate as irritants upon our soul and thus produce that internal condition which is alone known to us. Therefore we may con- sider material elements as matter simply. The other related assumption, that the soul, on the other hand, possesses physical peculiarities, perha[)s promises to be useful, but the popular consensus has not received it, but, rather, has contrasted the soul, as an immaterial being, to material elements and thus ])ro- duced the difficulties of the following chapter. (CHAPTER SECOND. tup: reciproc.'al action betwekx soil and BODY. §1. Let the possibility of an immaterial existence be admitted (of which more anon) — it is then customary to object that, in that case, no reciprocation, at least, between it and the body is possible. The latter won Id find on the shadowy soul no point of a)»plication for its physical forces; the sonl would produce no eifect upon matter by its inner conditions, thus the complete dissim- ilarity of the two would prevent all action. §2. To this it tnay be replied, that we deceive our- selves if we believe, in any case whatever, that we appre- hend the condition of a reciprocation, and if we consider that relation betwt^en soul and body in which this does not occur as an e.xceptional state of inadaptability. [f we observe the inner mechanism of a machine and the connection of its parts, we think we understand its operation because oui" observation has been al>le to notice various thinj^s al>out it. Upon a little retlection, however, we find that we do not understand either of the two conditions upon which rests the operation of OUTLINES OF PSYCHOLOGY. the macliinery, /. e., the cohtr-sion of its ])arts and the transference o^' the motion. Many wor:ls may, indeed, be exitended n])<)n it. hut we do not yet know how one element of a s(did ))()dy sets about it to hokl fast its nei«j:hl)or. or how it is able to cause the motion with which it is affected to cease and to reap])ear in another part. What we really observe in these cases is but the external imagery in which a series of processes passes by. each individual of which is united with its silccessor in a completely invis- ible and incomprehensible manner. In the relations between soul and l)ody we cannot follow this series of processes as far as we wish, but if we were able to follow it, for example, to the point where the physical excitement acts upon the soul, this latter transition would, indeed. l)e (piite unintelligilde, but no whit less comprehensible than the transference of a motion from one material element to another. §3, The source of the doubt above-mentioned is the false assumption, common even in antiquity, that only similars can o])erate one upon another, or be affected by each other. One can be tempted to make this assumption only by considering- the activity to be produced simply as a condi- tion which is already present in the operating cause a, and may be transferred to b without alteration, and. consequently, presupposes a similar lodgment in b OUTLINKS OF PSYCHOLOGY. as in a, and thus a, complete parallelism between a and b. On the other hand, we borrow from metaphysics the conviction that such a severing of the condition from that of which it is a condition and its transference to another subject is completely inconceivable. The effect of an a upon a b consists alwa^'s in the fact that a con- dition, A, of a is the occasion which ]n-oduces. according to an universal law, of wliich iu)thin<>' is to be said here, in b, out of its own nature, the condition B, which, in general, need have no similarity to the condition A. Even ordinary experience teaches that one and the same effect. A, may j)roduce the most various results, accord- ing as the objects, b, C, and d, upon which it acts, differ. We have, therefore, no right to set up coiulitions which must be fulfilled in order that a may affect b. The identity, or similarity of l»oth gives the ])ossibility of their operation no greater com])rehensibilitv or plaus- ibility than would their (lissiniilarity or even their incoiuparalnlity. tj-t. A l)oii(l betweeu body aiul soul is often denumded in order to nuike com])rehensible the i)ossibility of their reciprocation. However, bonds are only needed to unite those things which, of themselves, will uot act upon eacb other, but are (jiiite iudifferent to each other. The uniting ))ower of a bond consists in the fact that OUTLINES OF PSYCHOLOGY. 79 its elements are united with each other; nevertheless, we can not be always svi])posing upw connecting links, but come, finally, to an immediate reciprocal action of the individual elements which cling together without the intervention of any sort of machinery. :V bond between l)ody and soul would, then, only be needed if they were quite iiulift'erent the one to the other. If we had such a bond it would not help us. for the specific form in which the body would act upon the soul and the soul upon the body by means of it would depend not upon the bond, but upon the specific nature of the two connected eleuicnts and their ol)ligatiou to reci))rocation. Instead of one such l>ond then, we assume that both are connected by many peculiarly formed bonds. Each individual reciprocal action to whieh they are compelled by their own miture, is such a l)ond. which connects, not in a general. l»ut in a definite way. §5. We proceeded upou the agreeiuent that the notion of the soul as an iniuiaterifd being is possible. Now, however, even this is denierehensions which, at first, seem to represent the real are simply secondary a])pearances which the results of the reflex activities of elements, in them- selves entirely super-sensuous, are made known to us. OUTLINES OF PSYCHOLOGY. 81 Hence the notion, not of the immaterial, but of the material requires to be demonstrated, and the gulf which seemed to separate body and soul as two completely heterogenous elements and thus to prevent their reciprocal action really does not exist. \,Note. — The reader will be interegted to compare the ideas briefly set forth in this section with the dicta of modern materialism. (Compare the open- ing pages of Hermacn Ulrici's Leibund Seek). Some of the various phases of materialistic thought on the relations of soul and body will be gathered from the following sentences: — " Will is the necessary expression of a condition of the brain occa- sioned by external influences" (Moleschott). " Man is but tlio sum of parents and nurse, of |)lace and time, of air and weather, of light and sound, and of food and clothing; " or, accord- ing to Feuerbach, " Der Mensch niir ist was er isst," i. e., Man is but what he eats. The ttnal ultimatum— "Thought is as much a secretion of the brain as bije is of the liver or urine of the kidney" (C. Vogt) stands in bold ".". contrast to the teaching of our author here and elsewliere. — C. L. H.] CHAPTER THIRD. THE SEAT OF THE SOUL. §1. A.n immaterial being can have no extension but may have phice, and we define this as the i)oint to which all effects from without must be transferred in order to produce an impression n]wn this being, and from which alone this Ijeing exerts its immediate activ- ities upon the environment. In regard to the soul, no one questions that it is only present within its own body and here only acts immedi- ately upon its environment by the agency of the body. §2. It has been attempted to conceive of the soul's special relation to the body according to the analogy of our conception of the omnipresence of God. Weuuder- stand by this that God is as near with immediate efficiency to one point of the world as to every other, that his will neither requires to pass over any distance to reach the world element z nor needs any intermedi- ary means to apply it to z. But we do not, by any means, understand that the unlimited extent of the arena which God thus rules applies to himself as a per- sonal peculiarity. In like manner, it is conceived, the soul, without OUTLIXKS OF PSYCHOLOGY. 83 extension in space itself, is, in its own body, all-present. This analogy is, however, quite unserviceable. We have already seen in the discussion of feelings of double contact how nature succeeds in producing the illusion, so indispensable to the beatification of our life, that we are present with immediate sensation and motion in every part of our body. On the other hand, physiological experiments show that the soul stands only in immediate reciprocation with the central organ of the nervous system, with the entire remainder of the body, however, only mediately, through the nerves themselves. §3. We are accustomed to assume of a physical force that it operates in infinite distances without intermediate mechanism. It operates, however, in diminishing ratio, in that the intensity of its activity diminishes with the distance. According to the first condition, we may say of that body which is- the conveyer of the force, it is univer- sally distributed in space; according to the second, how- ever, we must confine it to a limited space, that is, where the activity is greatest. This analogy is also quite inapplicable. The slightest discontinuity in a nerve, even in closest proximity to the brain, destroys the reciprocation with the soul throughout the entire region supplied by it. It has, therefore, no force opera- tive at a distance which can overleap this separation. 84 OUTLINES OF PSYCHOLOGY. ' The third analogy alone remains, /. c, that of opera- tions which take place in contact through transmission of motions. §4. This analogy has been chiefly followed, and it has been attempted to find such a point in the central organ in which all sensitive nerves unite in order to deliver up their messages, and from which all motor nerves spring in order to distribute the excitements received to the body. This conception not only has certain inter- nal difficulties, but it, in general, does not agree with our empirical knowledge. Not only has such a central point of the entire nervous organism not been found thus far, but we have well-founded reason to assert that it never will be.* The question now arises how, under these circum- stances, the notion of a seat of the soul can he held ? §5. We return to our original definition, but extend it as follows: — We err when we assert that because a thing is in a given place it can act upon that environment. As long as we neglect the activity it is impossible to say what is meant by a thing's being in a place nor how it differs from its existence in another place where it would be exactly as well situated as in this one. We think the order of thought ought to be reversed, *See Part Third— Functions of the optic thalmuB aud corpora striata. OUTLINES OF PSYCHOLOGY. 85 and should say if it is in the nature of a being, a, to reciprocate activities with b, C, d, then, by this fact, its systematic position is determined, and, in the arrange- ment of the world in space, it is that point of which the immediate surroundings are formed by b, C, and d, But the connection of all things may, in general, be so many-sided that an element, a, is not only deter- mined to reciprocate with the group b, C, d, but equally immediately with p, q, r, while p, q, and r, on account of other relations in which they stand, cause its system- atic position, and hence its position in space, not to be near them, but separated from them by an interval. In this case the active element a would not have one, but, with the same degree of truth, several positions in space without being sub-divided into a plurality^ just as we conceived of God as omnipresent, but not himself extended. Omnipresence, of course, includes aJJ space, here, however, we must assert that the immaterial being must have several distinct seats which are separated by intermediate spaces in which their presence does not in the same sense reside. Nevertheless, no real difficulty inheres in this view. We have simply to rise above the power of ordinary training which leads us to conceive of the immaterial being according to the analogy of Ijodily atoms, and, therefore, ascribe to it a sensible, limited magnitude and form, and hence but a single position in space. 86 OUTLINES OF PSYCHOLOGY. §6. The question remains why certain portions of the brain have the preference as seat of the soul over others, although, so far as we know, there are no remarkable differences in the structure or arrangement. Here also we must alter the ordinary conception. A single element, a, is not designed to always stand recip- rocated with one kind of element, b, but not with another, c. Every being, a, is affected or excited to activity solely by uhat tak-es place in other beings. Let this activity be denoted by x, which, according to uni- versal natural law, is the operative premise from which it is designed that a new condition shall be produced in a, then it is produced, and a receives this influence, whether it is originated in b or c. On the other hand, if X is not such a premise, a remains indifferent and un- changed whether x occurs in b or c. In exactly the same way the soul will enter into reciprocity only with those points in the central organ in which all the com- binations, adjustments and rearrangements of physical excitations are carried on after the completion of which alone these can rise up into consciousness of the soul, or which are, in other words, the legitimate stimuli of its activities. §7. If one were able, therefore, to observe microscopic- ally as accurately what goes on within the brain as we may observe the anatomical structure, it would appear super- ficially just as assumed by materialism; i. e., in various OUTLINES OF PSYCHOLOGY. 87 points of the brain individual psychical processes would proceed at the instigation of physical processes there taking' place, and the unit being of the soul would never ap])ear as the object of such observation. However, we do not accept the interpretation given by materialism for these facts. These psychical functions do not take ])lace as self- evident appendages or products of the physical processes, they can only be conceived as possible if the latter act simply as excitements operating upon the peculiar nature of that soul-being which is omnipresent within these limits and not confined to a point, and thus lead- ing to the exercise of its own jjeculiar faculties. CHAPTER FOURTH. THE EELATION OF THE SOUL TO TOFE. §1. Experience could only lead ns to the conclu- sion that the soul originates and dies with the Ijody. Necessities, foreign to these theoretical investigations, have excited the desire to estaldish its inniiorfdlitii, and this has Ijeen attempted ))y including it under the notion of a substance which contains, even in its own iiatnre, the quality of indestructibility. This subordination leads to two nndesiral)le results which would gladly be avoided, namely, the reasons ])y which the human soul nniy be included under the notion of substance would apply equally to every animal soul. On the other hand, this indestructibility pre-supposes not only immortality after death, but endless existence before l)irth. and thus we do not kjiow where to Ijegin; nor does experience give us any evidence of such pre- vious existence. Finally, it would l)e asked, if the notion of substance contains such an unavoidable difficulty, is it, after all useful, and not rather a sim])le figment of the brain, and whether, in the former case, the soul would belong to that class which should be included in it. OUTLINES OF PSYCHOLOGY. 89 §2. In fact, substance is but a name for everything which is able to act upon others, to be acted upon, or to sustain various conditions and, in these changes, remains the same as a permanent unit. On the other hand, it is a figment of the brain to be- lieve that further explanation can be adduced as to how the faculty for such conduct is originated, and to seek this explanation by conceiving of a bit of rigid and indistructible substance in each thing, around Avhich nucleus the other peculiarities or conditions, by the which one such thing differs from another, are grouped. Such a notion, when applied, shows itself ever com- pletely unfruitful in explaining those appearances for which it was assumed. It does not appear how such a substantial nucleus can be consistent with the plurality and changeability of the peculiarities which we are accustomed to assume (by the use of a word without significance) ''inhere" in it. Briefly, then, things are not things because a substance is concealed in them, but, since they are as they are, and conduct themselves as they do. they pro- duce in our phantasy the false appearance of such a substance as the cause of their conduct. The soul, then, inasmuch as it, as unit-subject of its inner conditions, conceives not only of others but is conscious of itself, deserves, in the highest degree, the title of a substance or being. But this, on the other hand, does not at all justify 90 OUTLINES OF PSYCHOLOGY. the assertion that this capacity, if once exercised, must hen always be exercised, and cannot, in the career of the thing, be originated or cease to be. §3. For the decision of tliis matter we l)orrow from metaphysics a demonstration wliich stands opposed to the conception to which the study of nature has accustomed us. For the latter attempts to explain the course of nature by assuming a multiplicity of original elements, of which each might exist if the others did not. and which, further, have, in themselves, no necessary connection one with another, but are either brought into such relation or else had somehow been placed there, and which, finally, are obliged by general laAvs to exert one reciprocal action in one relation and another in another relation. On the other hand, we briefly assert that really no effect of one element upon another is conceivable with- out contradiction as long as they conceived of as origin- ally independent and unrelated one to another. It is only possible if we consider them as dependent modifi- cations of a single actual being which is in them all as the ground of their existence and, further, the reason why they are obliged, under definite conditions, to act in a definite manner, and, finally, as that which makes the fulfilment of the above-described obligations possible; or, otherwise expressed, all things are not what they are, neither do thev act as thev do because of an endowment OUTLINES OF PSYCHOLOGY. 91 of their nature which belonged to them before the world Avas. Neither Avas the world, at a later period, obliged to conform to them, so that there was only pro- duced, in consecjuence, what was permitted by these postulates. But they all exist, and operate as commis- sioned by this single absolute being: and all that we generally consider as the final unalterable elements and laws of nature have this invariableness and value only in conformity to the ])lan for the fulfilment of which they were ordained. This view was not invented to satisfy the present requirements, it is, rather, necessary in order to compre- hend the simplest effect of Oiie element upon another, but it is applicable to our case. It may lie within the bounds of possibility that all these varying appearances are produced by combinations of unchangeable elements at the dictation of universal laws. For this reason, then, there are in the world those constant quantities whose activities always occur in the same way and which are but the actions con- stantly produced or sustained by each individual exist- ence. But it also lies within possibility that there are other elements, only appearing in given points of time in the course of nature, namely, when all the conditions are met Avhich, according to the universal plan, can luring them into being. There is no reason why these elements, when once produced should not conduct themselves as simple , 92 OUTLINES OF PSYCHOLOGY. indevisible and independent foci of converging and diverging activities. Among these elements we number the soul. A further C(uestion — how these are brought into that con- dition of indejiendence — Ave dismiss as out of place. Nor can we explain how it is, or was brought about, that those constant elements exist and continue eternally. §5. At the place and moment in which, in the course of physical nature, the eniljryo of an organic l)eing is formed, the soul belonging to the organism is formed out of that universal being everywhere present, and this act is a consecpient of that physical process. Super- ficially viewed, materialism seems to be correct in stating that the soul originates in and with ( not, how- ever, out of and through) the body. And it is useless to question regarding the manner in which it appears, as it were, from without simultaneously with the body. So far as immortality is concerned, it is not a subject to be decided upon from a theoretical standpoint. We hold, as of general a]iplical)ility, only the funda- mental law that whatever has once been formed will endure as long as it has an unaltered value for the coherence of the world. Ijut will self-evidently cease to exist as soon as this is not the case. Yet this law is not applicable in our hands, we cannot presume to say what may constitute the merit which produces the perman- ence, or the lack Avhich makes it impossible. CHAPTER FIFTH. THE SOUL'S ESSENCE. §1. 1)1 investigating the essence of a thing we may first inquire how this thing differs from another; second, how it is that the content thus indicated can exist as a real thing. The second question may be answered in the case of objects whose distinctive peculiarities consist only in the form of a material previously existing. In this case we usually consider matter as the ''being/' and the form as unessential. But simple matter, like every simple being, cannot be continually derived from some- thing different from itself. We have often before dismissed, as unanswerable, the questions how it is that any content can exist, and act and be acted upon as a thing. Our inquiries must, then, be what are the peculiar characteristics consti- tuting the soul's real being, by which it is distinguish- able from other substances. We can only learn of tne nature of each thing, and in like manner of matter, through its operations and effects. It is, therefore, not an error, liut the natural method of psychology to define the nature of the soul thus reversely. 94 OUTLINES OF PSYCHOLOGY. The first systematic attempt, in the doctrine of the faculties of tJic sonI, has remained unfruitful. The multitudinous psychical activities were classified according to their resemblances, and it was, indeed, cor- rect to ascribe to each such group of actually produced activities a facultjj. However, this notion was not as fruitful as that of force in physics, for the physicist only seriously speaks of a force when, not only the form of the effect is known, but when a law can be given, according to which its magnitude varies in iiroportion to the varia- tion in certain conditions. The faculties of the soul, on the other hand, were simply abstracted from the fon)i of the activities and no law was found for them, thus simply a tautology was reached as, for example, in the statement that the faculty of sensation jiroduces sensation without ex- plaining under what conditions. On the other hand i>hysics has been successful only in so far as it has reduced all natural processes to motions of masses, By means of this similarity in the processes it was possible to accurately define the result obtained by the simultaneous and combined operation of various forces upon the same object. But psych- ical conditions can not ))e reduced to such a common standard. We have no idea of what would result from the com- bined action of the faculties of susceptibility aud of OUTLINES OF PSYCHOLOGY. 95 conception. What is known concerning it is derived independently of it from experience and a knowledge of humanity. Both these deficiencies are not to be removed by any better carrying out of the theory. It can only serve, then, as a convenient catalogue of spiritual activities but not as an explanation of them. §3. The unproductiveness of this theory, and the poor standard it supplies for the connection of the various faculties (which it always viewed as the expressions of an individual soul) induced Herbart to attempt the explanation of all these spiritual activities and fac- ulties as a series of results springing successively from a single primitive activity of the soul. The soul was considered as one of the super-sensuous, aljsolute beings of completely simple nature, which always remain unchanged if undisturbed, and yet, when they are affected by external irritants which would produce disturbances in their nature put forth activ- ities for self preservation. And these self-preservative efforts vary with the disturbances producing them. In the case of other real beings, as, for example, those composed of matter, we can know nothing of the character of this process of restoring the equilibrium. In the soul, on the other hand, we know, or dare to assume, that they, in general, are in the form of con- ceptions. 96 OUTLINES OF PSYCHOLOGY. By means of physical irritations, which Herbart did not follow further, the soul is induced to put fortii this reaction, and the conceptions here occurring. ,. e.^ of simple sensations, a definite color, sound or taste, are the simple elements through the farther reciprocation of which results the whole of the remainder of the soul life. We mention here, gratefully, only the previously mentioned explanation which elucidates the process of conception according to general mechanical laws. On the other haud. we cannot agree with the attempt to derive all the higher activities of the soul as inde- pendent mechanical products of this process of conception without the supjiosition of some faculty in it not yet men- tioned. This law was not indeed, considered necessary, for Herl)art himself admitted that even the simplest sensa- tions grouj) themselves in entirely distinct classes, colors, sounds, tastes, none of which are derivable one from another; that the soul thus really possess quite distinct faculties which we cannot derive from that unity which we still insist upon. Nothing, then, was to prevent the assumption that these sensations and their relations among one another operate as new stimuli upon the soul unit, and then produce entirely new reactions which it would, how- ever, be impossible to derive from these sources them- selves. Such an assumption would only be met by the OUTLINES OF PSYCHOLOGY. 97 demonstration that it is unnecessary, and that really all the higher activities are quite independent results of the reciprocal attrition of the simplest concepts. This demonstration has not succeeded as may be seen from the following examples. §1. We have already found it impossible that a soul, were it but a conceiving ])eing, should conceive of relations between its concepts other than they really are, for example, as though they were in space while they are not. If it does so, then it must add to this actual existence something new from its own nature which is not derived from the thing itself. In like manner it was found impossible to consider attention as simply the intensity of the conception itself; the subject which exerts all the applying activities in which the real office of attention consists would, in that case, be entirely wanting. We now find it quite impossible to consider feelings of pleasure or displeasure as inde- pendent results of the various positions in which the conceptions, during their progress, may become related one to another. If the soul were simply a conceiving being it would conceive all these facts accurately and indifferently, even though the}^ were fraught with its own destruction. The fact that it partakes in an interest in them is a new fact which must proceed from some other peculiarity of its own existence. Finally, no one could be persuaded that what we 98 OUTLINES OF PSYCHOLOGY. mean when we say " I will " signifies simply the access of a conception into consciousness through a conflict with forces which attempt to prevent it. However obscure and inexplicable the idea that in this case we have to deal with an act and not simply a happening — an act produced by ourselves, the unit- subject of our Avorld of concepts — yet the fact itself which we thus designate and discover immediately in inner experience cannot be displaced by this hypo- thesis which throughout explains nothing, any more than the appearance only of such an act could present itself to us as distinguished from its simple occurrence. We close, then, with the conviction that it is possible and necessary to credit to the unit-being of the soul more than a simple adaptability for conceptions, and that even these reactions of the first order which take place as a result of external stimuli, in the form of conceptions, may, by their relations and combinations? become new stimuli by means of which faculties of the soul not before affected are excited to expression. §5. The explanation of the origin of the higher spiritual activities from the lower must be given up. In the place of such a mechanical construction, another view may be presented, which affirms that the sum of spiritual expressions, let them originate as they may, are. at any rate, suited to one another, and necessary, OUTLINES OF PSYCHOLOGY. 99 hence, those ideas which express the destiny of the soul are completely realized. The Idealistic systems^ and particularly latterly that of Hegel, made this attempt. According to these, the world in general is not a simple fad^ it has also a meaning. In this whole every individual has its definite position, and the being of each thing consists really in the partial idea with the real- ization of which it is intrusted and through which it contributes its own to the unbroken whole of the ultimate or universal idea of the world. If we can formulate an accurate exhaustive expres- sion for this ultimate idea, we can derive from it the form of each thing, the totality of the faculties neces- sary to it, and, finally, the general laws according to which these must operate in order to reach that con- summation. As, however, that definition is impossible, instead of a scientific deduction, capable of proof and counter proof, we must accept one which comb nes, with more or less taste, more or less of aesthetic correctness, the single s])iritual activities with such a comprehensive expression as may have been found for this ultimate idea. The learned conceptions which are possible in the premises, and which have not Ijeen wanting have, moreover, become one-sided on account of an historic circumstance. 100 OUTLINES OF PSYCHOLOGY. The question coucerning the method and truth of our knowledge or concerning the relation between subject and o])ject has so absorbed all attention that the process by which the existing being becomes conscious of its own existence, /. e.. the development of self- consciousness is considered the real goal or the final content of the entire world-system. The soul appears simply designed for the solution of the problem of self- consciousness within the earthly life, and the various forms in which this office of pure intelligence is gradu- ally performed fill nearly the whole field of psychology. T\\Q content of this, however — that which is sensuously perceived, or viewed, or conceived — on the other hand, is quite as much neglected as the entire remainder of the soul life, of susceptibilit}" and volition, which only comes under consideration in as far as it can be applied to this problem of self-objectivity. CHAPTER SIXTH. THE MUTABLE CONDITION OF THE SOUL. §1. The life of the soul consists, not in a uniform possession, biit in the varying operation of its faculties. In this it is in most obvious dependence upon the body. The opportunity afforded by certain disturbances of the body has made it possible to define this dependence more accurately. Three interpretations of the observations made con- cerning them are, hoAvever, possible. Firstly, the organ disturbed may be the operative cause of the spiritual function which can not, therefore, be performed after its disarrangement; secondly, this organ may be the sole transmitter of the irritations necessary to the soul in order that it may be induced to put forth a function otherwise explicable out of its nature; or, thirdly, the disturbance may exert, either directly or by means of alterations which it induces in other organs, a positive activity of a repressive sort upon the soul, and this prevents, for a time, the expression of the faculty which itself persists. Only the first of these interpretations appears unten- able on account of the impossibility of considering psychical functions as self-evident products of physical 102 OUTLINES OF PSYCHOLOGY. processes. If we wish to prove the two factors actually connected, one or the other of the last mentioned inter- pretations would be necessary in every individual case, the first alone would require further demonstration. §2, If we understand by consciousness that which we more explicitly call the condition of wakefulness, the question arises upon what depends its opposite, /. ^., unconsciousness, the first example of which is normal sleep. In relation to this, it is plain that, in general, both methods of explanation are admissible, but that the entrance of sleep and the possibility of its inter- mission does not indicate an exhaustion of the nervous forces, so that they, consequently, are not able to pro- duce the necessary stimuli to continue wakefulness, buti rather, a positive hindrance, in various directions minute, but as a total, constituting the feeling of weariness which lessens the interest of the soul in the carrying on of the train of thought and which, by means of this abandonment on the part of the soul, is increased in its effectiveness. Instantaneous unconsciousness from fear appears to originate in the same way. Considered as simply a phys- ical stimulus the frightful vision or the jiews heard is very insignificant and harmless. Only after our reflection, which considers the significance of it in its entire con- nection with our existence does this perception acquire its fearful power. Then the process of our spiritual OUTLINES OF PSYCHOLOGY. 103 life may be disturbed immediately, and the bodily insen.- sibility following may be simply the reaction of these psychical disturbances. This view is not entirely excluded in the case of unconsciousness in sickness or after injuries of the brain. The restricting influences are felt partly in the form oi pain, but not necessarily so. As we are quite unconscious of the conditions prevailing in our nerves previous to sensation and only the latter enters consciousness, so, likewise, the con- sciousness may disappear without the workings of the forces which quenched it becoming objects of percep- tion. §3. It has, in recent times, been frequently thought that the activities of certain irritations conduce to the continuance of wakefulness and their absence to the production of unconsciousness. It is concluded from experiments upon hypnotism that in the complete exclusion of external excitements of sense and prevention of motion the entire spiritual activity is so reduced that the state of wakefulness cannot be maintained, but complete unconsciousness takes place, a process which has been in a few cases observed in human beings, but which affords no trust- worthy conclusion. Moreover, we know that when interest is not excited by some inner activity of the mind, as in a state of ennui, even the operatioji of external irritants does not prevent falling asleep. 104 OUTLINES OF PSYCHOLOGY. Positive agencies are also known which dispose to sleep, such are, a multitude of regularly recurring rythmic motions of the body, rocking, knitting, combing, the continuous viewing of large illuminated uniform sur- faces, the convergence of the axes of the eyes in squinting, etc. Lastly, the manipulations of the mes- merist belong here. Nevertheless, upon none of these methods can certain conclusions be formed, for the instances of their inop- eration are extremely frequent, and admit of a supposi- tion of a co-operating condition as yet unknown. In all cases, however, at the very most, only the external condition^ on the one hand_, and its effects, on the other, are known, while the intermediate processes which con- nect the one with the other are quite obscure. §L If the minimum activity of the waking condition, ?'. e., sensation of external imjiressions, be exerted, it does not of necessity follow that the next higher activ- ity, i. g., the consciousness of the relations between the individual impressions, should be present at the same time. It is well-known that in our daily experience, this latter activity may be absent, as when, for example, we follow with attention some chain of thought to which these impressions are foreign, or when we are excited by painful emotions. There are, however, pathological derangements, of a OUTLINES OF PSYCHOLOGY. 105 nature, indeed, as yet unknown, which produce inadapt- ability for the unification or understanding of impres- sions perceived in sense. §5. We do not need to assume a corporeal basis to explain the retention of the conception once received, ?'. ^., the fact of memory. For even in material ele- ments we cannot discover how far it is their materiality which causes the observed persistence of their condi- tions. On this account it would be equally pertinent to ascribe this peculiarity to every immaterial subject which is capable of acting or receiving action. However, the necessity of thinking of a vast number of various mixed impressions enduring within the com- plete unity of the soul favors the other view that this necessity would be better satisiied by assuming a large number of elements. Not as though the impressions produce a condition of quiescence by their reactions, but, rather, according to the analogy of light and sound waves, motions are assumed which extend over many elements and, unperceived, after interaction, undergo further development. Nevertheless, it would be imposs- ible to use this general analogy further in detail. Each image of an approaching object would, in each instant, be the source of new vibrations which do not obscure the previous one. How a single concept of the object can result out of these; again, how two simult- 106 OUTLINES OF PSYCHOLOGY. aneous motions can associate themselves so that the renewal of the one should reproduce the other without the production of a new impact; finally, how it hap- pens that one motion, which belongs to a partial impression of a complex image, awakens exactly those others which belong with it as parts of the same image — for all these questions a physical analogy is wanting. Although this discussion seems to make a corporeal basis unnecessary, still, pathological observations show that it is, in some form, present. The fact that those events immediately prior to the outbreak of an illness frequently are forgotten may be explained by the fact that their concepts had associated themselves with a sense of illness which is not present after convalesence, so that the key is wanting the touch of which alone could reproduce them in memory. Nevertheless, other facts — the impossibility of recall- ing certain similar groups of concepts, for example, sir- names or single sayings — do not admit of explanation. §(>. The unconsciousness of sleep is of various degrees of intensity which can be measured by the magnitude of the excitements necessai\y to waking. It is often incomplete in so far that, for example, irritations of the senses of feeling and hearing operate upon the consciousness and produce the consequent sensations. As, however, in sleep, that attention, which is OUTLINES OF PSYCHOLOGY, 107 exerted intentionally during wakefulness, and which is then conscious of the complete connection between the surrounding objects, chiefly through the instrument- ality of the sense of sight, is absent, the sensations reproduce themselves without the selection of those which are apparently connected by their contents, or are brought into connection by some prior process of conception. Upon this fact depends the fantastic char- acter of dreams, which very frequently collect about a very small nucleus of actual sensation complex imagery which, although concordant, is not in reality connected in the least with it. This activity of consciousness may so increase as to permit the correct answering of questions, and it thus becomes possible for those who are awake to direct, to a certain extent, the train of thought and, perhaps, even the actions of the sleeper, for no presiding conscious- ness of actual relations and the personal condition opposes the direct translation of the conception excited into the resulting motion. §7. We ascribe considers ble influence over the pro- cess of all spiritual conditions to the temperaments, by which is simply meant an expression for the amount and kind of excitability to external impressions; the greater or less extent to which the excited conception reproduces others; the rapidity with which concepts vary; the intensity with which they unite with them- 108 OUTLINKS OF PSYCHOLOGY. selves feelings of pleasure and pain; and the ease with which external acts associate themselves with them. Notwithstanding the infinite variety of temperaments considered in this sense, there ma}' be mentioned the four common ones as the most definite types: — The sanguine, exceedingly mutable and with vivid excitability: the pJilef/iiiafic, with slighth' varied and slow, but not on this account feeble, reactions : the choloric, w^ith one-sided receptivity and great energy in certain directions; the senfinienfal (in place of the melancholic), distinguished by especial receptivity to the susceptibilities of all possible relations, but which is not affected by the simply matter-of-fact. It is necessar}' to avoid confusing the temperaments wdth various pathological conditions or peculiarities of character, although it is clear that each temperament has its strong and weak side for moral culture and bodily health. We have no definite knowledge con- cerning the corporeal basis of the temperaments. §8. Phrenolof/ij or Cranioscoj)!/ has claimed to dis- cover, by external indications, a series of organs for the individual spiritual functions. This is, indeed, without any foundation, in as far as it sought to define the position of these organs and to separate them in space. On the other hand, it is not entirely in error when viewing certain external forma- tions as simply the indications which show that the^ OUTLINES OF PSYCHOLOGY. 109 otherwise unknown, conditions exist, upon which actu- ally depend, we know not how, the particular intensity of these functions. It is prevented from becoming such a useful collec- tion of facts, however, by another fault. Only those functions or talents can be taken into account which are not ambiguous and^ when present cannot be well concealed nor yet counterfeited when absent, for exam- ple, musical, artistic or mathematical talents, of all which we have actual examples enough of inheritance in a family. But peculiarities of character which can l)e estimated only by a delicate knowledge of human nature, and not even then with certainty, and which, in a given case, may be the product, not simply of natural abilities, but of education and accident, are not at all adapted to this determination, although often so used. §9. A Sensorium cotnmune and, more recently, a moforimn commune have been distinguished. The necessary activity of the first results from the fact that the individual impressions cannot become objects of the cognition of the soul as such but only after com- bination or some other adjustment. The organ has this office, the simple collection of the impressions into one place seems unnecessary. How far this process extends we do not know, apparently it may be related to the previously explained process of apprehension of 110 OUTLINES OF PSYCHOLOGY. space, to which, perhaps, a large part of the brain is dedicated. It would be assumed concermng a nwtoriuin coDiDinne that it combines the individual roots of the motor nerves in such various ways that there results a series of subordinated centres, each of which needs but a singJe impulse in order to set in motion at once many properly combined activities. The sort of effect which the soul exerts upon these points is certainly incorrectly conceived, if it be assumed that the impulses coming from the soul are of identical sorts and only distin- guished in their effects by the direction which they take, and hence the various termini which they finally reach. The determination of such a direction would be impossible unless the soul possessed a knowledge of the structure of the brain with which we cannot credit it. We assume, therefore, on the contrary, that eveiy concept of motion, a, which arises in the soul is a qualitatively different condition from another concept of motion, b. To a belongs the resulting condition A, to b, another, B. Both these conditions can only take place in those points of the nervous system Avhich are adapted by their organization to be excited thereby, just as a glass, for example, only responds to those tones which are capable of producing vibrations in it by impact. The impulses of the soul do not. then, recpiire to be directed, OUTLINES OF PSYCHOLOGY. Ill but find the place for their application spontaneously. It should not be understood, however, that they require to pass over a distance from a given point to that place. We should conceive the function of the organ of speech in a similar way, this being the only one which has, with considerable certainty, been referred to a definite spot in the hemispheres of the cerebrum. Injury of this spot prevents the possibility of com- bining the conceived sound-pictures of a word with the excitement of motions in the muscles of speech by which the actual articulation of the sound is produced. Although we can form Imt little conception of the sort of activity incumbent u]ion the organ, we are yet more in the dark as to the method by which such a dis- turbance in its activity can be produced as takes place in a pathological state of aphony. §10. For the higher spiritual faculties which consist in the judgment upon relations of given concepts, we do not know how to prove empirically a definite cor- poreal organ, nor yet how to conceive how such an one would subserve for the solution of the important part of the problem, /. c, the production of the act of judg- ment itself. It is conceivable, on the other hand, that this higher activity might be the complete and clear representation of those contents upon Avhicli judgment is to be passed, and hence might be considered but the undisturbed 112 OUTLINES OF PSYCHOLOGY. function of those organs which contribute, first, to the sensuous perceptions, then, to their reproduction and connection with others, finally, to the proper connec- tion with the feelings of the value of each. §11. There remains to be considered a large number of statements concerning abnormal spiritual activities in conditions of bodily ailment. The various instances of such cases are not all equally incredible. The assump- tion that cases exist of an immediate communication of consciousness with distant parts of the external world without the agency of the physical, cannot be dismissed a priori^ for all mediate perception must be reduced, in the last instance to immediate. Experience only can teach us when physical mediation is present and when not. Certain it is that the entire wakeful and spiritual life, which alone is amenable to accurate experimenta- tion, is connected with the external world by physical mediation. Senseless is the assumption, on the other hand, that the given appearances may be explained through- out by the operation of that animal magnetism which is supposed to be discovered. Again, it is not impossible that a simple sensation, such as that of light, can originate in nerves not designed for them, but it is quite impossible that an orderly apprehension of a multiplicity of sensations, for example, the reading of a letter, should take place in superficial nerves which OUTLINES OF PSYCHOLOGY. 113 are not, like the optic nerve, constructed for this com- bination of impressions. Finally, it is possible that various spiritual functions take place more vividly in such pathological conditions as diminish the regular intercourse with the external world, and thus remove those little cares and the timid- ity which in ordinary life stand opposed to the exercise of a given faculty. In these cases, for example, when a problem is solved in somnambulance which was before insoluble, this only takes place through the agency of those faculties which have l)een cultivated during the wakeful state. That nothing higher is reached in this condition than is attainable in a waking condition is shown by the unimportant content of all the disclosures received in it, and by the fact that the multitiule of such cases have not combinedly produced any advance in our knowledge. CHAPTER SEVENTH. THE REALM OF SOULS. §1. We have no reason to speak of a soul at all except where, without this assumption, facts would be incomprehensible. In reality, however, such inspiration may extend further than required by this test. An inspiration of all things has been conceived of, but this thought, although there may be good ground for it, has, as yet, remained unfruitful for the explanation of individual appearances. In sooth, plant-souls have been bespoken with great partiality, ( Fechner, Nanna, oder ueber das Seelenleben der Pflanzen; Leipzig, 1848,) and certainly inspiration is not connected with the centralized structure which we observe in animals and fail to find in plants. Never- theless, the more the organization of the plant, and hence the expressions, by means of which alone its inner life can become an object of our knowledge, varies from that structure, so much the less does it become possible to produce from this phantasy (although it may be correct) an object of science. The animal kingdom, then, alone remains as affording us such an ascending series in spiritual life. OUTLIXES OF PSYCHOLOGY. 115 §2 . -It would be a mistake to consider all animal souls as beings originally of the same sort, which either were afterwards furnished with powers or were adapted simply by the diversity of the external impressions for the greater or less development and the peculiarities of their spiritual perfection. We consider "soul," as before, only as a title which applies to all those beings which experience their inner conditions and the reactions from excitements in the form of concepts, susceptions and volitions. But that which is expressed by this term in common phrase, /. e., the real heinrf of the soul, may differ as essentially as we consider gold, silver and lead to do, although they only show this diversity by the differences in the degree of the same physical qualities, weight, cohesion, hardness and others. The question may arise where the idea of the instinct of animals comes in, to which is to be reck- oned not simply remarkable instinctive impulses but the entire typical life of all lower animals. Per- haps, for example, in the lower classes the souls are not prepared to the same extent for learning from experience, but, in agreement with their bodily organ- ization, have an original content in consciousness by which they are regulated in the same way that we are sometimes by the accidentally formed ideas of dreams. However, this assumption cannot be fruitfully pursued. 116 OUTLINES OF PSYCHOLOGY. As a farther assistance in the explanation it may be added that, in an entirely different organization of the nervous system, perhaps the vegetative processes, of which we are quite unconscious, are objects of percep- tion and starting points for acts which appear reason- less to us. Not less probably, there may exist sensa- tions of external circumstances, the organs for Avhich we do not possess, as, for example, sensitiveness to minute electric variations in the environment from which might result sensitiveness to changes in the weather, not as premonitions of the future, but as perceptions of what already exists. Nevertheless, it is wrong to refer all animal soul-life to such instinct. For certainly there exist in their actions accommoda- tions to circumstances in such a way that the same reflection and use of experience, upon which our every day existence rests must exist in them as well. §3. If the understand ing and its activity, fJiOiimply allow the process of conception to go on according to mechanical laws, but puts forth an activity which separates those conceptions not belonging together and not merely permits those belonging together to remain so, but causes them to be at once conceived in the form of general notions or laws indic- ating that they belong together. OUTLINES OF PSYCHOLOGY. 11' There is no occasion for referring such comprehensive reflection to animals in order to explain the purpose seen in their activities, and the way in which they adapt themselves to circumstances. The ordinary pro- cesses of conception (inasmuch as even they gradually associate themselves according to their affinities ) serve quite 8s well for them as they do even for man in the greater part of every-day life. If the understandbuj or fhougJif be considered as a distinctive character of man, the following circum- stances may be mentioned which favor its develop- ment: — The long period of helpless childhood, which makes the collection of many experiences possible; then the skilfulness of the hand which makes man a born experimenter, and permits a multitude of con- nected observations; finally, speech, partly because the sound images, as symbols of conceptions, serve to fix their content and make possible the combination of many conceptions into an object of internal contempla- tion ; partly, and chiefly, because communication causes a further development of each individual process of conception through the stimulating, enriching and cor- recting supervention of new chains of thought. §4. Reason is considered the most definite peculiarity of man, and by this is understood the faculty of per- ceiving immediately eternal verities in itself whenever external experience has furnished to consciousness the 118 OUTLINES OF PSYCHOLOGY. facts concerning which it has to form a judgment, par- ticularly concerning moral propriety or impropriety. We know nothing regarding the primal psychological origin of this simplest law of our knowledge and hence have reason to consider it one of those reactions in the original nature of the spirit which can never be explained by the external occasions which are, never- theless, necessary that it may be awakened, although this explanation has been attempted. It is, moreover, indifferent whether they be consid- ered as inborn endowments or acquired by experience in life, if it only be admitted that, after it has been formed, it is the expression of truth, found, indeed, in experi- ence, but, as to its content and value, quite independent of it. §5. Moral truths are designed to govern the /////. Of this, in like manner, w^e only speak in the case of man, according no volition to the acts of animals because we consider their acts as simply the natural results of iiti- puhses but not as acts of a will. Impulses are originally but feelings, and chiefly those of displeasure, or of unrest. They are usually connected with incitations to motion which, after the manner of reflex motions, lead to all sorts of motions which have proven, after more or fewer errors, the proper ones to allay that discom- fort. Then after the feeling of discomfort has com- bined with the concept of that act by which the OUTLINES OF PSYCHOLOGY. 119 discomfort was allayed, a real impulse is formed .which has a goal to reach, and which sways the acts of the soul. In the same way many operations of human life are performed which we incorrectly say are inlled when, in fact, simply no will was exerted to prevent their taking place. We can only speak correctly of irill when the motives of various actions and their values are compared in full consciousness, and then a choice is made between them. It is quite unreasonable to assume that we ex- press by the words ^' I will" no more than is involved in the future tense " I shall." This would only be the case if the verb, the future tense of which is used, itself means an act in the notion of which there inheres the idea cf volition. Unprejudiced observation must admit that the peculiar approval of a conceived act or the adoption of a resolution, however impossible it may be to construe it, is an actual process within us, inexplic- able by the mechanism of conception. §(». And if this characteristic of the will be conceded it would be expected, from the standpoint of explana- tory science, that the utterances of the will would be determined by definite laws. If ethics assert the free- dom of the will psychology need not be appealed to to decide, on the basis of, so-called, experience, whether this freedom is possible. It is not true that we find in our subjective observa- 120 OUTLINES OF PSYCHOLOGY, tion the determining causes of all our acts. Very often we find nothing, and, even where we think we have found something, it is ambiguous, for if the motives for two opposed acts, a and b, have been long compared in reflection, and then a decision in favor of a is formed, it will always afterward appear as though the reasons in favor of a, by their forcefulness had mechanically subdued those for b, and this semblance would result just the same if the decision in favor of a had been really reached by a completely undetermined freedom. It must be relegated to metaphysics to inquire whether the notion of such freedom is harmonizable with our universal apprehension of the world, and to practical philosophy to inquire if it promises the advantage which caused its employment. PART THIRD. THE STRUCTURE OF THE BRAIN. C. L. HER RIC K STRUCTURE OF THE BRAIN. PRIMITIVE ELEMENTS. §1. The paiimal body, complex and mysterious as it seems, and diverse and complicated as its various organs really are, is composed of nothing but cells and cell derivatives. As stated by Lotze, it is impossible to avoid conceiv- ing of man as a unit-entity surrounded by or resident in a heterogeneous agglomeration of corporeal units, and yet it is impossible to picture to ourselves the way in which the various processes which bring about sensa- tions and which are really only states in various unlike bodily elements transmit the perfected product to our spiritual apprehension. However, although there is no physical analogy for the process it must be accepted as a fact, and we may, at least, be interested to learn just what adjustments in the body are necessary to such and such spiritual affectations, and through what mediation the spirit controls the body. The nervous system is no exception to the above statement, and all of that wonderful mechanism which we call the brain, and which is the physical basis of character and the soil in which the soul, in its corporeal 126 OUTLINES OF PSYCHOLOGY. relations, is rooted, is a mass of cells and cell products like the muscles and bones which do its bidding. §2. All of these simplest morphological elements are descended, in the case of every individual, from one, or rather, two primitive cells — egg and sperm. Only in the lowest group of animals. Protozoa, does the entire organism consist of but a single cell. In this case the cell as a whole performs all the functions devolving upon a vital being, and, in the absence of nervous organs, the whole animal may be said to do the thinking and feeling as well as feeding and moving. This primi- tive condition is never entirely lost in any living cell however highly differentiated the animal, and however restricted, as a consequence, the functions of the indi- vidual parts may be. The last function which could be given up would be nutrition, for should a cell become too highly specialized to take nutriment its life would at once be lost. It is found, moreover, that others of the original functions persist, though to a different ex- tent in different types of cells, in many of the cellular elements of the body. In animals of a higher rank than the Protozoa differentiation is inaugurated by the subdivision of the primitive cell into numerous similar bodies and finally into groups of such cells, the func- tions of which differ with their position. §3. Ordinarily, the first stage in this process is the OUTLINES OF PSYCHOLOGY. • 127 formation of a loose aggregation of cells called the morula, after which a central cavity may be formed by the further subdivision and growth of the peripheral cells, and a hollow sphere called the hIasfuJu results. A portion of the cells may now become invaginated so that a double sack is formed. In this, or in analagous ways, a body, consisting of two germ layers, ectoderm and entoderm, arises, and from these two layers of cells all the parts of the body are produced by similar pro- cesses of invagination or by the migration of groups of cells to the cavities between these germ layers. In such animals as never pass beyond the f/astnda stage the ectoderm commonly furnishes the cells charged with locomotion and nervous functions, while the entoderm is charged with nutrition. Even in higher animals, in which these systems are perfectly distinct in adult life, the organs of locomotion and enervation spring primar- ily from the ectoderm, while the digestive system is only the greatly modified entoderm. §4. In the process of development, the cells, once similar, become greatly modified, and it is only by the help of high powers of the microscope and the delicate manipulations of modern histology that the cellular character can be discovered in many tissues. Nervous tissue consists, in general, of two distinct elements — ganglion cells and nervous fibres. The latter may be considered as simply appendages to the 128 OUTLINKS OF PSYCHOLOGY. former. The cell, as we have seen, is the unit of struc- ture, and as nerve cells are designed to exert their influence in all parts of the organism, it is evident that when differentiation of the body removes the generators of nerve power from immediate contact with the parts to be affected there must be provided conducting chan- nels of nervous matter to transmit the excitation. This is the office of the nerves. Nerve cells vary greatly in form and size, but consis of a nucleated, pigmented mass of sarcode, usually with no true cell wall, and giving off nerve fibres composed of a similar substance. Some nerve cells are so large as to be visible to the unassisted eye, while others are among the most minute morphological elements. Nerves are essentially bundles of minute fibres insolated by various protective sheaths. As a nerve issues from its cell it is usually without a sheath, and then consists only of a bundle of nerve fibres con- stituting the, so-called, ((xis ri/Iiiider. This, the essential portion, is surrounded by two sheaths which unite, node-like, at intervals. Each nerve is thus a bundle of primitive fiibrillae surrounded by the medular sheath and the primitive sJtenth of Sinnni. §5. Of both these elements, ganglion cells and nerve fibres, there are two sorts, motory and sensory. All the various procssses of mental life may be divided into two primary groups; first, those concerned with influences OUTLINES OF PSYCHOLOGY. 129 from without and, second, those which are designed to exert influences upon the bodily organs. So far, at least, as the simpler acts of mind are concerned, they may be said to consist of shocks from without and reac- tions from within, hence we expect to find, as we do, that the centripital and the centrifugal channels are connected by linking nervous threads. The simplest connection of a nervous system will then ]ncture to us a sensitive apparatus upon the surface of the body which selects certain of the many external irritants to trans- mit to the brain. Here the nerve terminates in a ganglion cell Avhich is excited to ac'ion, the kind of action being determined l)y the character of the stim- ulus^ its modification in the organ of seiise, but particu- larly by the structure of the ganglion cell itself. We must avoid considering the activity of the ganglion cell as canned simply by the impulse which is received from the nerve. The nerve furnishes the occasion — the form of the reaction depends upon the structure and position of the cell. The third link in this chain of processes is the transmission of this new and different stimulus to a ganglion seated at the root of a motory nerve. Here again it is conceivable that the character of the excite- ment is completely changed in a manner dependent very largely upon the position and structure of the uKjtory ganglion. The last nervous process is a state of excitement transmitted through the motory nerve which acts like an electric shock upon various muscles 130 OUTLINKS OF PSYCHOLOGY. at the periphenil termini caiisinir contractions in the sensitive myoloii material. All the above processes are explicable according to physical analogies, but this does not ex})lain in the least how any of these processes are In'ought into relation with the soul so as to excite in consciousness an appre- hension of external happenings or internal states. We discover from experience that sensations from various organs as well as the most diverse mental states succeed in producing activities in one and the same motory centre, so we are prepared for the discovery of anatomy that there is the most intimate anastaniosis of the various ganglion cells, so that the simple picture drawn above ninst be tilled in with many details. Xo ganglion is afEected without transmitting more or less of its agitation to neighl^ouring parts, and the intimacy of connection is different in c.ifferent sets of cells : thus the perfection of the lirain as an organ of mind depends as much ujxtn the perfection of the correlation and subordination of the various ])arts as upon the size and delicacy of its material. CHEMICAL CONSTITUENTS. §6. Before taking up the more intimate description of the brain, it may be well to mention some of the chemical peculiarities of nervous matter. Although little is known of the comjiosition of the materials in which nervous functions reside, it is at least certain that OUTLINES OF PSYCHOLOGY. 131 they are very complex and in a state of very unstable equilibrium. Of these substances Lecithin, Cerebin and Cholestrin, having the formulas C44H)oNP09, CsrHiegNOs, and C00H44O, respectively, are most im- important. Lecithin is a substance resembling fat^ composed of the radical of the fatty acids, phosphoric acid, and clycerine, united with the amine base, Neurine. In addition to these are various albuminous compounds from which the above may be derived. Another substance, Nuclein, is among the elements but is found in the nuclei of all active cells, so that it cannot be reckoned among the necessary constituents of nervous matter. The primitive fibrillae, as well as the nuclei of the ganglion cells are rich in albuminous matter, while the protoplasm of the ganglia and the nerves seems to be largely made u}) of Lecithin and Cerebrin. This much is clear, that the jihysical force liberated in all nervous processes is derived from the decomposition of the highly complex and unstable molecules of the nervous tissues. The materials needed to supply the waste thus produced are afforded by the blood, although some of the specific nervous compounds seem to be the result of a synthesis produced on the spot where they are needed from materials richly sup- plied by the general circulation. (For a valuable dis- cussion of the way the force resulting from the chemical changes taking place in the nervous matter of ganglia and nerve cells is applied, or the " ])hysiological 182 OUTLINES OF PSYCHOLOGY. mechanics of nerve-substance," see Wundt, Grundzuege der Physiologischen Psychologie, Chapter VI., under the above caption. ) A further discussion of this sub- ject is not here permissible. FOim AND DEVELOPMENT (3F THE CENTRAL P(JKTlON OF THE NERVOUS SYSTEM. §7. The earliest condition of the nervous system which we need to notice finds the brain and spinal cord in the form of a hollow cylinder somewhat expanded and modified anteriorly. This front or brain ])ortion now Ijegins to grow much inore rapidly than the rest and its walls expand and become variousl}^ folded upon themselves and almost all of the compli- cated mechanism of the brain in man is derived from repetitions of this process of in- and evagination of the walls of the primitive neural tube. Three expan- sions appear at first, forming the first indications of the differentiation about to take place. The anterior of these prominences divides to form the cerebral hemi- spheres and optic thalmi, the middle one forms the o[)tic lobes or corpus bigeminum, while the posterior one produces the cerebellum and medula ol)longata. (Fig. 1, Plate I.) The separate chambers thus formed are still connected with each other and the central cavity of the spinal cord. (Fig. 2, Plate I.) Now begins a separation of the above-described OUTLINES OF PSYCHOLOGY. 138 organs into pairs, a process which is nearly complete in the case of the hemispheres; the thalmi optic open out- wardly; the separation is simply indicated in the case of the lobi optici; while the cerebellum divides and again unites. As a result of this process, of course, the cavity within is greatly modified, that contained in the hemi- spheres becomes separated into two, called the first and second ventricles, that portion within the thalmi is called the third ventricle. The opening in the medula is called the fourth ventricle and is connected by a nar- row canal (the aqi(ff/(/i(cfii.'< sj/lrii ) with the third ven- tricle. There is also a small cavity connecting the cerebellum with the l)rain basis. The most remarkalde change which now takes place is the change of position in the anterior portion of the nervous axis. At first the brain is obviously the continuation of the spinal cord, and so remains in fishes and amphibians (Fig 8. Plate I), but in higher vertebrates great fiextures change the original position, and great and unequal growth obscures the original relations. Two im])ortant changes thus brought about may be mentioned. First, the excessive development of the cerebrum causes it to extend Ijevond and overlap first the corpus bigemiuum and finally the cerebellum; second, the growth also causes foldings and impressed lines called fissures, the first of which to appear is thefissura silvii. Another fissure is opposed to the silvian and nearly at right angles to it — the fissure of Rolando or medium sulcus. 134 OUTLINES OF PSYCHOLOGY, By this means the cerebrnni is divided into lobes, of which the frontal, ])arietal and occipital are most important. In man, the whole surface of the cerebrum is thrown into convolutions wliich conform more or less to the direction of the principal sulci mentioned (Fig. 4, Plate I). The spinaJ cord is that portion of the i)rimitive ner- vous tube which changes least, V)ut, notwithstanding, great changes in form and structure are encountered here also. The central camil liecomes reduced in size and the whole is divided into two symmetrical halves by a longitudinal fissure both before and behind. These halves are connected by two commissures or nerve l)U}idles — the anterior and posterior commissures. The substance of the cord is composed of grey material or ganglion cells collected in two masses in the centre of white external matter con- sisting 01 threads passing forward toward the l)rain. The nerves which spring from the anterior or ven- tral side are nu^tory while the posterior roots sup- ply sensitive nerves. (Fig. n * *Fisb.— Transverse Section of the Lower Part of the Spinal Cora. 6, Anterior; c, Posterior median groove; g, Spinal canal; *, Posterior; i, Anterior nerve roots; d. Anterior cornus, with lursrer cells; e, Posterior coruus, with small ganalion cells; /, AuterioT; h, Posterior cummiesuree. OUTLIJS'EB OF PSYCHOLOGY. 135 The iiiednhi ohJongata is simply a somewhat modified anterior portion of the spinal cord, and the rather simple arrangement of the nervous tiln-es is here ex- changed for a more complicated order. The longitudinal fibres group themselves into various bundles called the pyramids, the lateral and posterior Ijundles, which latter forms the funiculus gracilis, funiculus cuneatus, etc. Upon the pyramids is seated a pair of peculiar prominences called the olives. Tlie cefeheJhiin is differentiated early, and, like the other parts of the brain mantle, as distinguished from its l)asis, consists of an external or cortical layer of grey or cellular matter, which in man, is thrown into strong convolutiojis, thus presenting in section the regular hgiire known as the arl)or vitie. The cere- bellum receives several distinct l>ui]dles of nerves, the lower of which forms the j)r()ressus ad iiicd. ohJoin/a- tHiii. the upper being the processus ad corpus h'ujciu- innm. From the sides issue the /iroccssi ad jxDiteiii which unite to ' forui a liand of li]:)res p.. bridging over the med- ^"j- ula, and hence called the pons ra/ori. (Fig. 6.*) *Fig. &■— Basal portion of Brain from above. (A portion of the cerebellum is ren:oved.) 7"^, Thalmi optici; Core, Couarium : na di, Cori.usbigemiuum 136 OUTLINES OF PSYCHOLOGY. The spinal cord is ]H'oduced forward after passing, as we have seen, through the raedula. as the two crura which support, like stalks, the hemispheres. Seated upon tlie crura, and forming with them jiarts of the basis of the brain is the corpux hi;/ei)i/ninu. The position of the thai mi opf/'ri has been already referred to as forming the walls of the third ventricle. From the front of this chamber two small openings, the foramina of Monro, lead into the two ventricles of the hemispheres. There is a small appendage below the thalmi called the Jii/jwplnjsis. The two hemispheres are united in mammals by a strong, thick band — the rorj)Hs ca//osinti. The crura, or extensions of the axis of the spinal cord, unite with the hemispheres, and near this point of union is accumulated a large amount of grey cellular matter, forming a prominence projecting into the lateral ventricles called the rorpxs sfridfiim. We need not i)roceed farther with the descrijition of anatomical details. The liistology as well as the configuration of the cere- bral elements associate them in two groups. The first, consisting of those parts which are the direct continua- tion of the s])inal coixl, constitute the basis of the Ijrain, and agree with that orsran in having the grev matter (nates nnd testes); TV, Pedunculus cerebelli superior (Processus ad Corp. liisremiinini); /"?«, Pediincuhis cerebelli luedialis (Proci»ssiii^ ad pontem. Betwecu /*»-. aud /'wi. isseenihe Pednnciiliis cerebelli inferior— Process ad med. oblongatam) : g, Girdliug fibres; jc, Fiuiieiilus ciuieatiis; /gf, Funic- ulus i;racilis; ,« , Funiculus lateralis: C. Cerebellum. OUTLINES OF FSYCHOLOOV. 137 arranged al)out the canal, or at least, medianly, while that part of the Ijrain, including the cerel)rum and cere- bellum, which forms a covering- for the others, has the cellular elements arranged cortically in a more or less thick layer, below which are white fibres passing down- ward toward the base of the brain to find exit with the medula. The cortex of the brain is about 2 mm. thick and, as a whole, as well as in its cellular elements, is invested with a web of delicate threads of connective tissue. This iiei(ro(/f/a serves not only to isolate the cells, but to convey blood vessels to each individual cell. These cells, Avhich are. perhaps, the most important of the cerebral organs, are arranged in layers, the su])erficial layers containing smaller, the deeper layers larger cells. The nerves coming from i)eripheral ])arts first, after reinforcement in the Ijase of the l)rain, con- tribute their stimuli to the superficial or sensory cells. The resulting activity in these smaller cells seems then to be imparted the larger or motory ganglion cells, from which the impulses there gener- ated are conducted again to the base of the l)rain and. after correlation and various modifications, an impulse to motion is transmitted to the ap})ropriate Biuscles. Nervous threads are thus either centripital (sensor}') •or centrifugal (motory) — names derived from the direction in which tlip nerve is adajited to transmit impressions. 138 OUTLINES OF PSYCHOLOGY. THE CONNECTION BETWEEN THE BRAIN AND OTHER PAliTS OF TIFE NERVOUS SYSTEM. §8. The sensory nerves sprin"' from the posterior ]>}irt of the spinal cord M'hih' the motory threads arise anteriorly, and the continuation oi these nerves toward the brain within the spinal cord maintain, in general, the same relations. There is, however, a crossing of a cer- tain ])oj-tion of the fibres, especially in the case of sen- sory nerves. This is a provision against accidents. In general, however, the anterior and posterior nerve l)undles represent the nerve roots of the corresj)onding sides while the lateral bundles contain fibres from both. By dividing the spinal cord on one side there results a total loss of motion and increased irritability on that side, and diminished ]iower of motion and irrital)ility on the side opposite. In the medula. also, there is a cross- ing of fibres from one side of the bod}' to the other which occurs in different sets of nerves at different points. The cutting of these nerves above this point causes total loss of motion to the portion of the ()i)po- site side of the body sup})lied by their termini. The cerebeUiim is connected directly with the spinal cord by the fibres of the processus ad med. oblongatum. The processus ad jiontem sends fil)res down to end in the grey cells of the bridge from which connection is afforded with the corpus striatum and other anterior centres. The fibres passing toward the cerebrum enter OUTLINES OF PSYCHOLOGY. 13^ the cells of the red nucleus of the crown of the crura. It is not known that any of the fibres pass directly to the cortical substance of the cerebrum. It therefore appears that sensory fibres transmit stijnuli to the cere- bellum which do not produce sensations because they never reach directly that part of the brain over which consciousness bears sway, but that the excitations are transferred to ganglion cells at the base of the Ijrain Avhere the stimuli necessary to produce motion are set into operation immediately. If this be the case we are prepared to understand how the cerebellum comes to be the seat of reflex and automatic activities as is usually maintained. Thus the function of the cerebellum seems to be in part the same as tliat of the grey ganglion cells of the spinal cord, which, in like manner, form second- ary centres independent of the consciousness through which sensory stimuli switch off, as it were, from the regular routes to the Ijrain. to l)e transferred to ap]iro- priate niotory fibres. From the optic thalmi, corpus striatum, and other basal portions of the brain fibres pass to all parts of the cortex of the cerebrum, and, as some recent authors claim, the former is receptive to sensory nerves, optic, auditory and olfactory, as well as those of ordinary sensation^ while the latter is the starting point for motory nerves. It is farther assumed that after the sensations are trans- formed into appropiate stimuli and these are co-ordin- ated they are transferred directly to the small cells in 140 OUTLINES OF PSYCHOLOGY. the perijihery of the cerebral cortex givino; rise to j^.ensa- tioii. Then, it may be, new forces are developed, accom- panied by chemical decomposition and the evolution of heat. These forces are conveyed along the nervous threads springing from the small cells to the larger deep - seated cells of the cere- bral cortex, (Fig. 7.*) and here, as in new generators, motory impulses are produced, and these are conveyed to the corpus striatum where correlations and combinations are affected, which result in the production of more or less complicated and prolonged motions of the body, in which they are assisted and partially controlled l)y unconscious pro- cesses carried (ni in the grey matter of the cerel)ellum and spinal cord. Such, most simply expressed, is the present view of simple cerebral activities. The detailsf which fill in and complete this outline are abstruse, and only obtain- able bv recondite researches. *Fio;. 7 — Diagram of the Courses of Nervous Stimuli, according to the theory of Luys. O TVi., Optic thalmi; C5., Corpus- striatum ; 0, Eye; a. Ear; /, Nerve trausmitting ordinary si'usations ; /, Small (seusory) cortical cell; II, Large (motory) cortical cell. The coutbl; of the currents indicated by arrows. +The above statements with reference to the functions of the optic thalmi are taken from Luys and may be found in Recherches sur le systeme OUTLINES OF PSYCHOLOGY. 14 1 PHYSIOLOGY OF TPIE BRAIN. §9. The simplest f auction of the central ortj^ans of nervous system is reflex artiritij. In its simplest form {his would consist of the transference of a sensory stimulus directly to a motory nerve. Practically, how- ever, it is necessary that the sensory affection should undergo a change before it is suited to act upon a muscle. Organs for this, purpose, as we have seen, are the ganglion cells of the spinal cord, medula and cere- bellum. Simple reflex activities lodge in the spinal cord, while those of a higher order occur in the medula. Breathing, swallowing and the beating of the heart are such activ- ities. Certain conditions in the capillaries of the lungs, for exam])le, produce excitements in nerves passing to the medula which, without the aid of consciousness or of the will, produce the necessary muscular exertion to cause inhalation, while, ordinarily, no such eifort is exerted in expiration. Reflex activities are found to be intimately connected, and this is explained by the vari- ous intimate anastamosings which takes place between the cells of the medula. Thus quickened breathing uerveiix; or, in Englith, in the Brain and its Functions, by tlie same author, forming one of the volumes of the luterniitloual Scientific Series. The writer IS forced to admit that these views are far from proven, and, indeed, arecon- tradicterl In the results of many experiments. Nevertheless there can be no doubt that such a relation as is here described exists between .-otne of the cells iu the brain, and if not thete, it matters little for the present purpose, lu the case of the corpus striatum facts seem unanimous. 142 OUTLINES OF PSYCHOLOGY. causes accelleration of the pulse, and certain affections of the ofustatorv nerve are accompanietl by reflex motions in the mimic muscles of the face. It is found that the brain exerts a restricting influence upon the reflex activities so that the removal of the hemispheres increases the reflex actions. This may, perhaps, be explained by supposing that that part of the stimuli which would normally be transmitted to the cerebrum is deflected upon the subordinate fibres leading to reflex centres. Automatic motions are a subordinate class of reflex activities in which the stimulus does not come from Avithout. /. e.. is not adapted to produce sensation, but •consists of a change in the condition of adjacent inter- nal organs. The vast majority of such motions seem to be pro- duced Ijy changes in the circulation or in the blood itself. The tensity of the muscles of the capillaries and the beating of the heart is regulated automatically, as is the breathing in part. Experiments seem to prove that the cereheUum is designed, through the correction of various sensations, for the regulation of voluntary motion as well as for certain reflex activities of a different sort. The removal of the cerebrum causes dizziness, uncertain gait and. often, undesigned motions, although the will is easily exerted, and the connection of the motor roots with the <;orpus striatum is unbroken. OUTLINES OF PSYCHOLOGY. 143 Of the fiinctioiis of the eerehrum it is not necessary to speak farther. What tlie phjsioh)g'ical Inisis of the higher spiritual functions is we are quite unable to say. The accompanying diagram indicates portions of the cerebrum which have been found, with greater or less certainty to ])e connected with the perception of certain classes of sensations or the production of spec- ific motions. (Fig. 8.*) DEVELOPMENT OF SENSORY FUNCTIONS. §10. Our knowledge of sensory functions is derived from investigations of the anatomy of the external organs of sense, but also in part from the l^ehaviour of animals when affected by different stimuli. Such investigations seem to ])lace it beyond peradventure that all the more complicated sensations and sensory organs are derived from the differentiation of primitive sensations and organs originally identical. Ordinary sensation, iuclnding the sense of touch, of temperature, and muscular sense, seems to he the starting point. *Fig. S.—Mofory Centres of the Brain. A, Motory centre of Facialis ard Hypogosf^ie region ; B, Motorj- centre of arm nnigcles; C. Motory centre of leg muscles; D, Motory centre of speech: U, Sensory centre of speech ; F, Visual region (?); S, Visual region. 144 OUTLINES OF PSYCHOLOGY. In the mostloAvly animals the sarcode wliich constit- utes the entire body must be the seat of every sensation by which the animal can ])e affected. Tt is assumed that those irritants which produces motions in the sar- code also give rise to sensations, ])ut that these will exhibit as diversity froui each other in ))roportion as one part of the body is different from another. Light prob- ably is perceived only as warmth, and even those pigment flecks in the Infusoria which undoubtedly serve to absorb and thus condense the light may not give rise to the sensation of light. The development history of the organs of sense sup- ports the idea that all sensory functions are derived from those of ordinary sensation. The development proceeds in two ways; first, the sense of touch becomes more highly differentiated by the development of sjjecial tactile organs; second, organs adapted for specific sensations are produced, so that the nerve termini become sensitive to special stimuli, such as light, sounds, tastes and odors. In all cases, however, these organs are produced by modification of the outer surface of the l)ody. The development of the tactile sense is earliest, and goes hand and hand with the production of special organs of locomotion. The clothing of cilia found in the Infusoria serves both purposes at once. In the case of insects we find sensory organs composed of rods seated on the enlarged termini of nerves, the rods OUTLINES OF PSYCHOLOGY. 145 being simply designed to communicate motions to the sensitive cell below. (Fig. 9.) This constitutes a transitioji to the more highly developed tactile organs in which epithelial cells of peculiar form enclose or include the termini of sensory nerves. The teeth, nails and vibrissa? are examples of accessory tactile organs in higher animals Avhich are not themselves sensitive, but stand in intimate relation to the nerves. In cases where no special apparatus is developed — and this applies to the majority of our sensory nerves — the ends of 'the nerves seem to be free between the epith- elial cells. Special organs of touch occur in the skin and in vari- ous inner organs, as the capsules of the joints and the mesentaries. Tactile splieres consist of two or more colls in a capsule, between which are disc-like organs usually parallel to the surface. ( Fig. 10. ) The office of these organs appears frequently to l)e the intensification of the pressure, etc., or its direct api)lication to the nerve. Among the specific senscrv organs those of taste and smell seem morphologically most nearly related to the organs of touch. Among lowly forms both these senses seem to be lodged in the same organs or the functions are not yet distinct. Organs, not only for recognizing but for producing odors, seem to be present in certain insects, as butterflies, and serve to assist the 146 OUTLINES OF PSYCHOLOGY. sexual instincts. The termini of the olfactory nerve correspond to the simple condition of the organ of touch where it consists of rod-like bodies seated on the nerve cell. In the sense of taste there is greater differentia- tion and the cells which constitute the termini of tlie nerves are enclosed in beaker-like groups of cells which are situated below the surface. Similar organs under the skin of fishes have been thought to indicate a sixth sense. (Figs. 11 and 12.) The organ of hearing seems to have been derived from the transformation of a ciliated surface. It is possil)le that even in the ciliated Protozoa the cilia, which are so easily affected by sound waves, may render them recognizalde. Most invertel)rutes and some vertebrates possess ears which consist of cavities lined with cilia and containing otoliths which seem to communicate the oscilations produced by sound waves to the cilia and theni-e to the nerve. An advance on this simple ear. which can hardl}' be supposed to distinguish different tones is furnished by such as have the cilia or rods of different sizes and lengths, each length apparently cor- responding to a definite wave length. Hensen (in the Zeitsch rift fur irissenschaffhcJic Zoolof/ic, xiii, p. 874) claims to have demonstrated by immediate observation that different filaments respond to differences in pitch. In many insects otoliths are wanting, but the rods are more solid and are covered by a tense membrane acting like a tympanum. The various classes of verte- OUTLINES OF PSYCHOLOGY. 14:7 brates, beginning with the fishes, exhibit a gradual dif- ferentiation and increase in complexity. The auditory sac, which is usually bi-lobed. develops on one side the semicircular canals, and on the other the cochlea. (Fig. 13.) The perfect ear is a Avonderfully complex organ, the physiological significance of the various parts being but imperfectly understood. It has been supposed that certain modified epithelial cells covered with cilia of various lengths serve to record the varying pitch of tones. This, so-called, or(j((n of corti has been compared to a bar]), each string of which is attuned to respond to a definite tone. The most credible hypothesis seems to be that the analysis of a harmony into different tones is accomplished by the membrane lining the cochlea, the varying width and tensity of which may make it better adapted for the purpose than a series of rods of varying length. Wundt supposes musical tones are distinguished in this way while tones which are com- posed of irregular vibrations, /. e., noises, may be recog- nized by the bundles of hairs before mentioned. Other parts of the organ seem to be designed to concentrate the sound waves, or to serve as dam]>ers upon the receiving organ. The organ of vision consists essentially of a receiving nerve and deposits of light-absorbing pigment. If the pigment flecks found in certain Infusoria, and especially in many low Avorms where they are closely connected with the central ganglia, are really eyes, Ave have in them 148 OUTLINES OF PSYCHOLOGY. examples of this simplest condition. In rotifers, etc., the cells in which the pier of lenses, each fitted to but a single rod or retina cell are grouped together like a mosaic and it is necessary to suppose that the frag- mentary images produced by each lense are united in the central ganglion into a continuous representation of the field of vision. This theory is called that of mosaic vision. The eye of man is not modeled after the compound eye of insects, but upon the simpler type offered by worms and mollusks. The pin-hole camera, a device by which a dim image is produced in a dark chamber by rays of light entering through a minute aperture, is mimiced by the eye of the nautilus. (Fig. 15.) A second chamber in which is developed a lense changes the pin-hole camera to a photographer's camera in which lenses secure the dis- tinctness of the image, while the larger size of the aperture greatly increases its brightness. An illustra- tion of this sort of an eye is furnished by the higher Cephalopoda (Cuttlefish). (Fig. 16.) OUTLINES OF PSYCHOLOGY. 149 The eye of vertebrates differs from that of the cuttle- fish chiefly in the fact that the elements of the retina are arranged in the reverse position. This is due to the greater complexity in the embryological development of the former, so that the epithelial layer out of which the retina is formed suffei's a double instead of a single invagination. The accompanying diagram (Fig. 17) indicates the arrangement of the various elements of the retina. It is proven that the rods and spindles are sensitive to light while the ganglion cells and the filaments of the optic nerves are not at all so, though they are more im- mediately exposed to its action. The ends of the rods are imbued with a purple red pigment which is exces- sively sensitive to the influence of light, changing rapidly in color when exposed to it. This pigment is constantly renewed by the process of nutrition during the life of the animal. The optic nerves pass to the corpus bigeminum and usually cross^ or form a cJiidsDia in their passage. This crossing is only complete when the fields of the two eyes are quite distinct. The larger the part of the field of vision the two eyes have in common, the more near the optic-nerve fibres are to being equally divided. (^Fig. 13.) In man it is found that the fibres passing to the inner half of the two retinas cross while those from the outer half })ass directly to the portion of the corpus bigeminum on the same side. 150 OUTLINES OF PSYCHOLOGY. A destruction of one half of the corpus begem- inum results therefore in the blindness of half of each retina, Avhile binocular vision is still possible for the remaining halves. The above outline touches upon a few points which may serve to introduce the reader to a line of study second to none at the present time in interest and importance. For a careful review of the whole field refer to Wundt's Physiological Psychology. PLATE I. Fig. 1. — Emiinjo of L'ltick. Fb, Fore-bniin ; Mb, Mid-brain: Mb\ Cerebellum; Mb^, Meclnla oblongata; Ai\, Auditory vesicle; Pi'. Primitive vertebra?: Mf\ Mesial or neural fold: T, Cau- dal lobe. Fig. 2. — Lonfjifudnial Section of Brain of Frog. J, 2, Lateral ventricles, or chambers of the hemi- spheres; .3, Chamber of optic thalmus. or third ventricle; i, Chamber of cerebellum; 5, Fourth ventricle: m^, Aquajductus Silvii. Fig. 3. — Brain of Fixh. (Pohjpterus.) A, From al)ove: B, From the side; 0, Olfactory lobes; H, Hemisphaees; Tit, Optic thalmi; Lo, Lobi optici; Ce, Cerebellum: J/o, Medula oblongata. Fig. 4. — Brain of Human Fcr'.fns, af seren monfJis. F, Frontal lobe: F. Parietal lobe: 0, Occipital lobe; T", Temporal lobe: S, Fissura Silvii; B. Sulcus of Rolando: MO, Medula: C, Cerebellum. Fig. 9. — Sensory apparatux in the Frobosis of Fly. n, Nerve; _r/, Ganglion cell; /', Tactile rods. Fig. 18. — Diagram of the Course of Xerre Fibres, passing from the retina to the brain. PLATE I, K. V. ^ Fid. 3. PLATE II. Fig. 10.— Tactile bodies. A, B, Tactile spheres from the bill of a duck; (', Tac- tile body imbedded in papilla of human skin; e, Epi dermis: )i. Nerve; s, Tactile body. Fig. 11. — A, An epithelium cell with two olfactory cells, from Proteus: g. ganglionic portion of olfactory cell; B, Epithelium aiL^- ollactory cells of man. Fig. 12. — Gtfstafonj Cnjtfroiii MoiifJi of Babbit. ^, Entire; B, Isolated sensory cells from such a cu}). Fig. 13. — Diagram.'^ of the Development of the Labij- rinth in (A) Fishes. (B) Birds, (C) Mammals: Y. Utriculus; .S, Sacculus: C, Cochlea; R., Recessus laby- rinthi. Fig, 14. — Eye of Spider in Section. L, Lense; ?, Epidermal layer; s, Rods; f/. Ganglion cells; p. Pigment. Fig. 15. — Diagramatic Sectio)i oj the Eye of Nautilus. B, Retina; o n, Optic nerve. Fig. 16. — Diagramatic Section of the Eye of a Cuttle- fish. L. LI Lenses; el Eye-lids; B. Retina; og. Optic ganglion: on. Optic nerve; int, Integument. Fig. 17. — Section of Huntan Betina. i, Membrana limitans interna; _r/\ Ganglion layer; (/2, Second ganglion layer; r/^, Third layer of ganglion cells: b. b^. Granular layers: a, Rod and spindle layer; e, External pigment layer. PLATE II Fid. 13. fid. 12. UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. KiHBS,3EPlVT3 SEP 4RK'fl BIOMED. riD BB3BBS0CT 2-W- °^m/ 1 7 75 BIOMEO LIB. DEC 5REC'D nn L9-50m-ll.'50 (2554)444 THE LIBRARY UNIVERSITY OF CALIFORNIA LOS ANGELES 0.::^ u q\V 'mi i>^&V ;>v£'i > ■ 'i^' ^iV'j*. o j^