Jacques Maritain Center :
Psychology / by Michael Maher, S.J.Locus of the Soul. -- There has been much discussion among philosophers, Ancient and Modern, regarding the precise part of the body to be assigned as the "seat" of the soul. Some have located it in the heart, others in the head, others in the blood, others in various portions of the brain. The natural inference from such a diversity of opinions is that no special area of the organism is the exclusive dwelling-place of the vital principle. The hopelessly conflicting state of opinion on the question would seem to be due to the erroneous but widely prevalent view, that the simplicity of essence or substance possessed by the soul is a spatial simplicity akin to that of a mathematical point. As a consequence, fruitless efforts have continually been made to discover some general nerve-centre, some focus from which lines of communication radiate to all districts of the body. The indivisibility, however, of the soul, just as that of intelligence and volition, does not consist in the minuteness of a point. The soul is an immaterial energy which, though not constituted of separate principles or parts alongside of parts, is yet capable of exercising its virtue throughout an extended subject. Such a reality does not, like a material entity, occupy different parts of space by different parts of its own mass. In scholastic phraseology it was described as present throughout the body, which it enlivens, not circumscriptive, but definitive; not per contactum quantitatis, but per contactum virtutis. Its presence is not that of an extended object the different parts of which fill and are circumscribed by corresponding areas of space, but of an immaterial energy exerting its proper activities ubiquitously throughout the living body. As it does not possess extension, it is not susceptible of contact after a quantitative manner, yet it puts forth its peculiar virtue, and acts with the same efficiency as if it possessed a surface capable of juxtaposition with that of a material body.
The Soul is not confined to any particular spot within the organism. -- The argument may be formulated thus: The site or locus assigned must be conceived either as extended or unextended. If the latter, then: (1) all hope of any physiological justification of the selected spot must be abandoned, since the smallest cell, and a fortiori every general nervous ganglion, must occupy an extended space; and (2) no particular unextended point has better claims than any other; therefore on this hypothesis the soul might with equal reason be located in almost any part of the body. If the site allotted be extended, then the chief merit claimed for this view is abandoned. If the simple soul is allowed to be capable of inhabiting a really extended locality, the exact area of the district is of little philosophical importance: the soul's indivisibility is equally unaffected whether the space be a cubic inch or a cubic foot.
The Soul is present, though in a non-quantitative manner, throughout the whole body. -- It is, moreover, so present everywhere in the entirety of its essence, although it may not be capable of ubiquitously therein exercising all its faculties. The proof of the previous proposition implicitly establishes our present doctrine; but reflexion on the thesis defining the union of soul and body recently proved, completes the argument. The soul, since it is the substantial form of the body, vivifying and actuating all parts of its material subject so as to constitute one complete living being, must by its very nature be ubiquitously present in the body. For it is only by the immediate communication of itself that it can so actuate and vitalize its co-efficient as to constitute a single substance. Again: since the soul is an indivisible essence or being, whenever it is present it must be there in the entirety of that essence or being; consequently, the entire soul is present in the whole body and in each part -- tota in toto corpore et tota in qualibet parte.
Difficulties. -- The chief objections urged against the present thesis seem to be the following: (1) The soul is the subject of sensations, but these, it is asserted, are originally felt only in the brain, and by experience thence transferred to the peripheral extremity of the irritated nerve; consequently the soul exists only in the brain. (2) It is impossible to imagine how a simple or indivisible Being can be simultaneously present in several parts of an extended space. (3) If the soul is thus diffused throughout the body, it must be capable of increase and diminution with growth; and also of occasional amputation of portions of its substance.
We may observe in reply: (1) Even if the brain alone be the centre of sentiency, yet the entire organism is the subject of vegetative life, and must be throughout animated by the energy which dominates the continuous processes of waste and repair. (2) Imagination is no test of possibility; we have experience only of the modes of action of things conditioned by space of three dimensions, and so cannot picture the being or action of an agent free from such limitations. We are similarly unable to imagine how unextended volitions can move extended limbs, or how spatial pressure can excite any mental state, but we have shown the absurd consequences which follow from the denial of the universal conviction of mankind on these last points. (3) The soul is not diffused throughout the body like water in a sponge. It must he conceived as an indivisible essence, without mass or quantity, exerting energy and putting forth its virtue throughout the animated organism. Those activities, however, which require a special organ are limited to the district occupied by the bodily instrument. In so far as the material subject by the limits of which vital activity in general is defined and conditioned, increases or diminishes, the soul may be said in figurative language to experience virtual increase or diminution -- an expansion or contraction in the sphere and range of its forces; but there is no real quantitative increase in the substance of the soul itself.
Phrenology. -- In the early part of this century, the physicians Gall and Spurzheim elaborated a " Physiognomical system," which pretended to determine precise localities on the surface of the brain where various mental powers are situated. Gall marked out the skull into twenty-six, and Spurzheim into thirty-five divisions, each of which was supposed to cover a definite field of the brain constituting the "organ" of some particular mental aptitude. The theory thus assumed above two dozen primary faculties or propensities, such as those of homicide, property, theft, wit, number, secretiveness, etc., lodged in separate compartments in the surface of the brain. Consequently, by measurement of human skulls, the relative vigour of the several propensities could be easily discovered, since special "bumps" or protuberances indicated, it was supposed, greater or less endowment in the corresponding faculty.
Phrenology, Craniology, or Cranioscopy, as this pseudo-science was called, has long since fallen into complete discredit, under the destructive criticism of both Psychology and Physiology. The scheme of "primary" faculties was arbitrary and artificial in the highest degree. The powers and aptitudes enumerated are not isolated or independent in the manner implied. Many of them are complex capabilities involving varied forms of mental activity. Moreover, intellectual faculties cannot be conceived as located in organs in the way represented. The progress of physical science, on the other hand, has proved the erroneous character of the views of the phrenologists concerning the physiology of the brain.
Localization of Cerebral Functions. -- Nevertheless, though Phrenology in its originally ambitious character is now generally acknowledged to have been past been exploded, Cerebral Physiology has for some twenty years past been working diligently at the kindred question of the localization of brain functions. The leading scientific authorities in the second quarter of this century unanimously declared themselves against the hypothesis of localization in any form. Flourens, Magendie, Longet, and other distinguished writers pronounced, on the strength of numerous experiments and observations, that scarcely any particular portion of the cerebral substance is essential to the performance of any particular psychical operation.{1} Consequently, the classical Physiology from 1820 to 1870 proclaimed that the brain as a whole was the single organ of the mind, that the quantity, not the locality of the brain which is destroyed affects mental activities, and that the degree of imbecility induced is, roughly speaking, in proportion to the amount of cerebral matter removed.{2}
Some experiments, however, of the German physiologists Fritsch and Hitzig, in 1870, threw serious doubts on the then prevalent doctrine, and a new movement of research, which still continues, was initiated, with the result of completely overthrowing the old teaching. By a series of elaborate experiments on the brains of dogs, monkeys, and other animals, Ferrier, Hitzig, Munk, Luciani, and more recently Flechsig and Von Bechterew, have established a fairly definite theory of localization of "motor-centres" -- that is, of areas in the cortex of the brain the irritation of which produces movements in particular limbs. The cerebral areas corresponding to some of the senses have also been made out with tolerable accuracy, others with less definiteness. Of the physiological concomitants of particular intellectual activities nothing is at present known, though some progress -- how much is as yet uncertain -- has been made towards the determination of "association-centres."
Method of research. -- In the study of cerebral functions three chief lines of investigation present themselves: (a) Experiment by stimulation and extirpation of particular portions of the brains of the lower animals; (b) Cerebral Pathology, or the science which deals with brain diseases in human beings; and (c) Comparative Anatomy and Histology, which examine the structural connexions of different parts of the brain and nervous system throughout the animal kingdom. Thus, the stimulation by electricity of certain areas in the cortex of the brain of dogs, monkeys, and other animals, is found to excite movements in the neck, arms, fingers, legs, tongue, etc. Conversely, the extirpation or destruction of these same portions of the brain temporarily suspends the power of movement in the corresponding limb. Again, postmortem examinations often show that atrophy and disease of the cerebral substance of these areas have been concomitant with paralysis of the appropriate limb. Moreover, several cures of such local paralysis have also been effected by the venturesome remedy of trepanning the skull and removing tumours found to exist where anticipated.{3} Finally, comparative study of the structure of the brain in different species of animals tends to establish the identity of the "areas" constituting the "motor-centres" of the several limbs; and it also shows that the number and definiteness of such "areas" increase in proportion as we rise in the animal kingdom and examine more highly specialized brains. And quite recently the study of embryonic anatomy has enabled Flechsig to reach valuable results by determining the date at which certain neural connexions are completed, and nerve-fibres attain maturity and are capable of functioning.
Results. -- By these various methods of research Perrier succeeded in mapping out on the surface of the brain above a dozen "motor-centres." Successive explorers have subdivided and largely increased the number of these areas. They are mostly situated in the vicinity of the summit of the cerebrum, about midway between the top of the forehead and the back of the head -- technically in the neighbourhood of the fissure of Rolando and the calloso-marginal fissure. (See, at the beginning of the book, Fig. vi. and Fig. vii., 1, 2, 3, 5, 6, and a, b, c, d.) The cortical areas on which visual impressions are "projected," that is, the spaces in the surface of the brain with which the images of sight are believed to be directly connected, are located mainly in the occipital lobes, in the hind portion of the cerebral hemispheres. (Fig. vii. 13, 13'.) Injuries here cause, it is alleged, not merely blindness, as in the case of retinal disease, but actual derangement of the faculty of visual imagination. (Seelenblindheit.) The auditory area is allotted to the upper convolution of the temporal lobe (Fig. vii. 14); and "word-deafness," "auditory asphasia," or inability to image, and consequently to understand articulate sounds, even whilst general hearing remains, was shown by Wernicke to be occasioned by lesions in this district. Previous to Wernicke, in 1861 Broca had found that motor aphasia, or the disorganization of the faculty of intelligent articulate speech, was caused by injuries in the third frontal convolution, which lies a little to the front of the subsequently discovered hearing-area. (Fig. vii. 9.) The difficulty of ascertaming the nature of the sensations of taste and smell of animals when subjected to experiments has made the localization of the cerebral correlates of these latter senses much more dubious. Indeed, we are warned by some of our best physiologists to receive with considerable caution even the most confident assurances of enthusiastic observers, especially when once they pass beyond the comparatively simple problem of determining motor-areas.{4}
Notwithstanding the considerable progress made in exploration, much of the brain, especially in the frontal region, being "silent," or not responsive to stimulation, its precise functions have remained unknown. For this reason there has been a constant tendency among physiologists to assume that this unoccupied cerebral territory is "the seat of general intelligence," without, however, venturing to explain clearly what they mean by this vague phrase. We have already shown the absurdity of attempting to conceive the higher rational activities as spatially situated in or exerted by bodily organs; but as we suggested in the first edition of the present work, these unclaimed districts may supply the material basis for memory, imagination, and those internal sensuous faculties upon which intellect is more immediately dependent. We now find that the progress of cerebral physiology during the last few years tends to confirm this conjecture -- which is indeed as old as St. Thomas.{5}
Thus the recent contribution of Flechsig lies in the advance he has made towards the establishment and closer definition of what he calls "association-centres" as distinguished from the previously acknowledged "projection-centres" -- the motor and sensory areas in direct connexion with sense-impressions and movements. To the former he allots quite two-thirds of the cortical substance of the human brain, reserving only one-third for the latter, whilst in most of the lower animals the distribution is reversed. Of these higher centres he affirms that "they are apparatus which combine the activities of the various special senses, inner and outer, into higher unities. They are association-centres of sense-impressions of different qualities, visual, auditory, etc. They make their appearance accordingly as subject of a 'co-agitation,' as the Latin language had prophetically characterized thought, and they may therefore be specially termed "association or co-agitation centres."{6}
As the chain of reasoning by which the reality of these higher centres is determined is necessarily more complex, and the evidence more fragile than that by which the "projection" motor and sensory areas are defined, we must be cautious in assenting too easily to the facts claimed to be established, before they are thoroughly confirmed -- and even then care will be needed for their correct interpretation. The circumstance, too, that serious lesions involving the destruction of large quantities of brain in this region without appreciably affecting any mental operations are frequently met with, ought to warn us of the precarious character of even the most plausible inferences in this subject.{7}
The "motor-centre" is usually found on the side of the head opposite to the bodily member to which it is specially related; but speech and other psychical operations not belonging definitely to either side of the organism are generally dependent on physical processes in the left hemisphere, except in the case of left-handed persons, who, it is said, are "right-minded" or rather "right-brained." The disease of aphasia in right-handed persons is, as a rule, accompanied by a lesion in the left frontal convolution. It seems also fairly proven that symmetrical portions of the brain in the right and left hemispheres are capable of performing similar functions; and it is chiefly -- though not exclusively -- in the relations subsisting between these corresponding parts that we find exhibited the law of substitution, which has constituted such a serious objection, or at all events limitation, to the value of all theories of localization.
Objections. -- On this general fact, together with negative instances presented by Pathology, the case of the opponents of localization mainly rested. It is true, said they, that irritation of a motor-area excites movement in the corresponding limb, and conversely, the extirpation or destruction of this part of the brain temporarily extinguishes or enfeebles the power of movement; but, nevertheless, if the animal be kept alive, it may after a few days recover complete use of the member again. In other words, some new portion of the cerebrum is capable of adopting the suspended function.{8} The part most fitted to do so seems to be in the first place the symmetrically corresponding area on the other hemisphere, and then the cerebral substance immediately surrounding the damaged centre. In addition to this difficulty post-mortem examinations have revealed several cases in which a very large part of one side of the brain, and even a not inconsiderable portion of both were atrophied or decayed, although no derangement in psychical operations, or in the action of the corresponding limbs, had been noticed during life. These objections admonish us how imperfect our knowledge of the relations between the brain and psychical action still is, and they also show how little foundation there is for materialistic dogmatism. At the same time we do not think they are conclusive against the doctrine of localization in every form. They indisputably demonstrate that the "centres" are not instruments of an absolutely fixed and permanent character like the external sense-organs. But they do not disprove the statement that the various sentient and motor operations of the soul, both presentative and representative, are, in ordinary conditions, specially dependent on particular parts of the brain; whilst the evidence on the other side makes this latter assertion well-nigh incontrovertible. They establish, however, that the principle which dominates the living organism has, within certain limits, the power of adapting to its needs and employing as its instruments other than the normal portions of the cerebrum.{9}
Although from a strictly methodical standpoint this topic would have been more appropriately dealt with at the beginning of this volume, we have preferred to handle it here at the end of Rational Psychology. We believe that its philosophical significance, or insignificance, can be better estimated, and the precise worth of materialistic deductions drawn from the doctrine of localization more accurately measured at the present stage of our work. The statement that the progress of Physiology has discredited or disproved the doctrine of the spirituality of the soul, is so frequently to be met with that it is extremely desirable the student should have at least a general notion of the character and value of the most recent investigations in Cerebral Physiology. Vague sweeping assertions, especially when uttered by men distinguished in Physical sciences, often give rise to a completely mistaken idea of the nature of the "recent advances in Physiology." We trust that our sketch of the subject will assist the reader to appreciate the true worth of such materialistic declarations.
Mode of Origin of the Soul -- Of philosophers holding erroneous ideas regarding the origin of the human soul, some have conceived it as arising by emanation from the Divine substance; others as derived from the parents. The former theory starts from a Pantheistic conception of the universe, and is in conflict with the simplicity and absolute perfection of God. The hypothesis that the soul is transmitted to the offspring by the parents -- and hence called the theory of Traducianism -- has taken a variety of forms. Some writers have maintained that the soul, like the body, proceeds from the parental organism: others that it comes from the soul. This latter opinion was advocated in Germany, in the early part of this century, by Frohschammer, under the title of Generationism. The soul in this view is generated, or perhaps more accurately speaking, created by the parents. Rosmini taught that the sentient principle arises by generation or traduction, and is afterwards converted into the rational soul by a mysterious illuminative act of God, through which the intellect is awakened to the idea of being.
Traducianism, whether understood of a corporeal or incorporeal seminal element, is an inadmissible theory. As regards the derivation of the rational soul of the child from the body of a parent, it is obvious that such a supposition is based on a materialistic conception of the nature of the mind. Nemo dat quod non habet: a spiritual substance cannot proceed from a corporeal principle. The derivation, however, of the rational soul from the soul of a parent is equally untenable. Every human soul is at once a simple and an immaterial substance. Consequently, the hypothesis of any sort of seminal particle or spiritual germ being detached from the parental soul is absurd. If the soul of the child, moreover, were generated or evoked out of the potencies of matter, it could not be a spiritual being endowed with intellect and free will, and intrinsically independent of matter.
Creation. -- Opposed to these various theories stands the doctrine according to which each human soul is produced from nothing by the creative act of God. The acceptance of this thesis is a logical consequence of the rejection of the previous views. By creation is meant the calling of a being into existence from nothing, the production of an object as regards its entire substance. The material things which we meet around us are a result of transformation or change, not of creation -- though of course their ultimate constituents must have been originally created. A spiritual being, however, cannot be effected by any such process of transformation. If produced at all, it must be formed from nothing. Now, the human soul is a spiritual substance, whilst at the same time it is of finite capacity, and therefore a contingent being. But because of its contingent and limited nature it cannot be self-existing; it must have received its existence from another being. On the other hand, inasmuch as it is a spiritual being intrinsically independent of matter, it cannot have arisen by any process of transformation; for, if it did so arise it would necessarily depend as to its whole being on its subject. Finally, since God alone, who exists of Himself, and who alone possesses infinite power, can exert the highest form of action, calling creatures into existence from nothing, the production of the human soul must be due immediately to Him.{10}
Difficulties. -- The chief objections urged against the doctrine of creation are the following: (1) The sentient-vegetative soul in man is of the same genus as that which informs the brute; consequently, since the latter is generated by substantial transformation, so is the former. (2) Like end must have like origin; but the human soul is immortal; therefore it must never have had a beginning. (3) The theory of creation involves continuous exercise of miraculous power on the part of God. To these difficulties the following answers may be given: (1) If the root of sentiency and vegetative life in man were an organic principle completely and intrinsically dependent on the body, as it is in the lower animals, then there would be no ground for affirming a special mode of origin in the case of human beings. But, although man's soul is generically related to that of the brute, it is separated from the latter by a specific distinction which involves this different mode of genesis. (2) The second objection has seemed very forcible to some minds, and we find even Dugald Stewart{11} holding that it destroys the argument for everlasting life based on the simplicity and incorruptibility of the soul. Yet when we reflect and demand proof of the assumption on which the objection is based none is forthcoming; and it is certainly not self-evident. God alone is without beginning, but He can will to exist whatever is not intrinsically impossible, and He may will it to last for ever. Consequently, there can be no absurdity in His creating from nothing a simple incorruptible being which He designs never to perish. (3) A miracle is an interference with the laws of nature, but in the given case creation of souls, when the appropriate conditions are posited by the creature, is a law of nature.
Time of its Origin. -- When does the human soul begin, to exist? Plato taught that previous to its incarceration in the body the soul had from all eternity resided among the gods in an ultra-celestial sphere. (p. 255.) The theory of metempsychosis or Transmigration of souls, has been held under one shape or another by many Eastern thinkers. It is, however, in all its forms, a gratuitous hypothesis. It is based on the false view which conceives body and soul as accidentally and not substantially or essentially united in man, and it possesses not a vestige of real argument.
Among modern philosophers, Leibnitz has considered human minds along with all the other "monads" to have been created simultaneously by God, at the beginning of the world. All souls were conserved in a semiconscious condition inclosed in minute organic particles ready to be evoked into rational life when the fitting conditions are supplied. Proof or disproof is here out of the question. If a writer asserts that his own soul, or that of anybody else, existed centuries ago in an unconscious state, we cannot demonstrate that the proposition is false; we can only point out that there is no evidence for such a statement. It is simply a gratuitous assumption. No sufficient end can be conceived for the sake of which such an unconscious life could be vouchsafed to the soul, and, consequently, it may be rejected as an unwarrantable hypothesis.
The Schoolmen taught that the rational soul is created precisely when it is infused into the new organism. The doctrine took two forms. Following the embryological teaching of Aristotle, St. Thomas held that during the early history of its existence the human foetus passes through a series of transitional stages in which it is successively informed by the vegetative, the sentient, and, finally, by the rational soul. Each succeeding form contains eminently and virtually in itself the energies and faculties of that upon which it is consequent. The advent of the rational soul only occurs, St. Thomas maintained, when the embryo has been sufficiently developed to become the appropriate material constituent of the human being; and this rational soul itself subsequently exhibits a gradual development in the manifestation of its powers, exerting at first merely the inferior forms of vital activity, later on sentiency, and only long after birth its higher rational faculties. The embryonic history of man is, then, in this view, that of a progressive evolution in the course of which the future rational being passes through a series of transitory stages not unlike the various grades of life to be found on the earth.{12}
The rival theory, which seems to have much in its favour, held that the rational soul is created and infused into the new being in the originating of life in conception; and that it is this rational soul which by the exertion of its inferior vegetative functions directs the growth and development of the embryo throughout its course.
Doctrine of Lotze and Ladd. -- On this question of the origin of the soul, Professor Ladd, to whom we have frequently been able to refer in terms of agreement, seems neither very satisfactory nor very clear. "Whence comes the mind of every man?" he tells us, "is a question with which metaphysics especially in the crude form in which it is found in theological (Why not add 'and scientific'?) circles -- naturally busies itself." Having rejected the traducianist and evolutionist hypotheses, he asserts that "the creationist theory of the origin of the mind in the form in which it is popularly conceived is no less unwarrantable or even unintelligible." He deems the doctrine that "God produces an entity called the soul, and puts it ready-made, as it were, into the body," to be absurd. His own view is that "the origin of every mind, so far as such origin is knowable or conceivable at all, must be put at the exact point of time when the mind begins to act (consciously); its origin is in and of these first conscious activities. Before this first (conscious) activity the mind is not. But even thus it cannot be admitted that any mind springs into full being at a leap, as it were. For the origin of every mind is in a process of development."{13} In brief, the soul's conscious "activities are its existence." This is virtually Lotze's conclusion (Metaphysics, § 244); and flows from his theory that a being is merely what it does.
Criticism. -- This view, which, maintaining the soul to be a "real being," distinct from the body, yet constitutes the essence of the soul in conscious activity, is in the first place exposed to serious difficulties based on the facts of periods of unconsciousness. The objection of the "naive metaphysics" of common sense is not precisely that which Professor Ladd suggests: "Where then is the mind in deep, dreamless sleep?" (loc. cit. p. 386.) But: "Does the mind in its entire reality cease to exist every time that conscious activity ceases? or, Has a man's soul no more reality during a state of coma from which he recovers, than it had a thousand years before he was born?" The logical consequence of the doctrine that the human soul begins to exist only at the first moment of consciousness -- or rather, if we understand Professor Ladd rightly, at the dawn of self-consciousness -- would seem to be that the human infant is without a soul.
The objection to creation as implying the insertion of a "ready-made" soul is based on an unfair representation of the doctrine. All spiritualists who, like Ladd and Lotze, maintain the existence in the adult being of a soul really distinct from the organism must necessarily admit its primary origin to have been abrupt -- the first appearance of a particular being of a totally new order, and so even the "modified creation" which Ladd accepts inevitably involves this same distasteful notion of "ready-madeness." The truth is that the most rational view and that least exposed to difficulties of this kind, is that form of the scholastic doctrine which teaches that in the origin of the new human being the creative action is exerted according to universal law prescribed by divine wisdom, in the act and at the instant in which the incipient vital principle is evoked in the germinating cell.
Origin of the First Human Soul. -- Darwinian Theory. -- The modern doctrine of Evolution ramifies into a large number of sciences, and its satisfactory discussion involves a multitude of questions pertaining to Biology, Geology, Physical Astronomy, Rational Theology, and Scriptural Theology. The business of the rational psychologist, fortunately for us, is neither the Theology nor the Philosophy of the Evolution hypothesis, as applied to the animal species or even to the body of man: our official concern is with the Soul.
The Human Soul cannot be the result of the gradual evolution of a non-spiritual principle. -- This proposition is the logical outcome of the chief doctrines on which we have insisted throughout the volume. The argument by which we have established that each individual rational soul owes its origin to a Divine creative act, proves a fortiori that the first of such souls must have thus arisen. Since even the spiritual soul of a human parent is incapable of itself effecting a spiritual soul in its offspring, it is evident that the merely sentient soul of a brute could still less be the cause of such a result. Again: the human soul, as we have shown, possesses the spiritual powers of Intellect and Will, and is therefore itself a spiritual principle, intrinsically independent of matter; but such a being could never arise by mere continuous modifications of a vital energy intrinsically dependent on matter. Self-consciousness, Free-will, Conscience, are all facts sui generis which could never have been produced by the gradual transmutation of irrational states. In a word, all the proofs by which we established the spirituality of the higher faculties, and of the soul itself, demonstrate the existence of an impassable chasm between it and all non-spiritual principles, whether of the amoeba or the monkey. The special intervention of God must, therefore, have been necessary to introduce into the world this new superior order of agent -- even if He had previously directed the gradual development of all non-spiritual creatures by physical laws.
{1} "On peut retrancher, soit par devant, soit par derrière, soit par en haut, soit par côté, une portion assez étendue des lobes cérébraux, sans que leurs fonctions soient perdues. Une portion assez restreinte de ces lobes suffit donc à l'exercise de leurs fonctions. A mesure que ce retranchement s'opère. toutes les fonctions s'affaiblissent et s'éteignent graduellement. . . . Enfin, dès qu'une perception est perdue, toutes le sont; dès qu'une faculté disparait, toutes disparaissent." (Flourens.) Cf. Bastian, Brain as an Organ of Mind, p. 520.
{2} Sur des chiens, des chats et des lapins, chez un grand nombre d'oiseaux, j'ai en occasion d'irriter méchaniquement la substance blanche des hémisphéres cérébraux; de la cauteriser avec la potasse, l'acide azotique, le fer rouge, etc.; d'y faire passer des courants électriques en diver sens, sans parvenir jamais à mettre en jeu la contractilité musculaire: même résultat négatif en dirigeant les mêmes agents sur la substance grise des lobes cérébraux." (Longet.) Cf. Surbled, Le Cerveau, p. 149.
{3} Cf. Surbled, Le Cerveau, pp. 239, seq.
{4} Thus Professor Foster, in the latest edition of his able Textbook of Physiology, reminds us that the cessation of particular sensations occasioned by lesions in particular parts of the cortex of the cerebral hemispheres does not prove that the cortex of the hemispheres is the 'seat' of the sensation, . . . it only proves that in the complex chain of events by which sensory impulses give rise to full conscious sensations the events in the cortex furnish an indispensable link." (Pt. III. p. 1094) And elsewhere: "The interpretation of the results in which we have to judge of sensory effects, are far more uncertain than when we have to judge of motor effects. We have to judge of signs our interpretation of which is based on analogies which may be misleading." (Ibid. p. 1077.)
{5} Mediaeval cerebral anatomy was naturally in a rudimentary stage, and some of the reasons assigned by the Schoolmen for allotting faculties to particular localities are quaint; but St. Thomas's theory of localization -- borrowed, however, from the Arabian physiologists -- is still of interest: "Est ergo (interior) Sensus Communis a quo omnes sensus proprii derivantur, et ad quem omnis impressio earum renuntiatur, et in quo omnes conjunguntur. Ejus enim organum est prima concavitas cerebri, a quo nervi sensuum particularium oriuntur, . . . Secunda vis interior est Phantasia . . . et hujus organum est post organum sensus communis in parte cerebri quae sic non abundat humido sicut prima pars cerebri in qua situm est organum sensus communis et ideo mellius potent retinere formas sensibiles re absente. (Nam humidum bene recipit, et male retinet: siccum vero e contrario bone retinet et male recipit.) . . . Tertia vis sensitiva est AEstimativa (vel Cogitativa). . . . Organum autem hujus potentiae ponitur in brutis in posteriori parte mediae partis cerebri. In hominibus autem ejus organum ponitur in media cellula cerebri, quae syllogistica appellatur . . . (et haec facultas) quae in aliis animalibus dicitur aestimativa naturalis, in homine dicitur cogitativa, quae per quamdam collationem hujusmodi intentiones adinvenit. Quae etiam ratio particularis dicitur, quia scilicet est collativa intentionum individualium sicut ratio universalis intentionum universalium . . . Quarta vis sensitiva interior est Memorativa. . . . Organum autem hujus potentiae est in posteriori concavitate cerebri." (De Potentiis Animae, c. iv.)
{6} Gehirn und Seele, pp. 22-24. Cf. the scholastic doctrine on the Sensus Communis and Vis Cogitativa, p. 93, above; also the last note. Although judging from the stormy past history of cerebral physiology, Flechsig's theory of association-centres is not likely to remain long unchallenged, his methods of investigation are sound. But he needlessly damages the value of good scientific observation and experiments by mixing facts with dubious metaphysics and crude materialistic hypotheses, when he lapses into language of this sort: "Man is indebted for his spiritual superiority in the first degree to his association-neuron. Anatomy, comparative anatomy, and clinical experience combined show decisively that these association-centres are the chief subjects of the spiritual life, and that consequently they may and ought to be designated 'spiritual centres,' 'organs of thought' (dass sie somit als geistige Centren als Denkorgane bezeichnete werden dürfen und müssen)." (Ibid. p. 61.) After what we have already urged (pp. 240-246, 466-472), we trust it is unnecessary to dwell further on the ineptitude of describing any mass of cerebral matter -- whether frontal or occipital, cortical or sub-cortical, as a "spiritual centre" or an "organ of thought." Higher intellectual activity may presuppose as a condition certain concomitant sensuous and cerebral processes, but the agent or subject of such spiritual activity must be an indivisible being.
{7} Cf. Ladd, Physiological Psychology, pp. 265-268, 296, 297.
{8} According to Goltz: "It is not possible, by extirpating any amount of the substance of the cortex on either side, or on both sides, to produce a permanent laming of any muscle of the body, or a total loss of sensibility in any of its parts. It is, however, possible thus to reduce an animal to a condition of almost complete idiocy. . . . No part of the cortex of the brain can, then, be called the exclusive organ or centre of intelligence or feeling; but the psychical functions are connected with all of its parts." (Cf. Ladd, op. cit. p. 298.) Goltz's chief experiments were performed on three dogs, one of which he succeeded in keeping alive for eighteen months deprived of nearly all the brain substance. The extirpation was effected gradually in small pieces at considerable intervals. The psychical effects, however, seem to be quite different when the removal of cerebral material is rapidly executed, though in such cases the animal speedily perishes. See W. von Bechterew, Bewusstsein und Hirnlokalisation. pp. 38-45.
{9} The original researches of Dr. Ferrier on this subject are to be found in his work, The Functions of the Brain. Bastian's volume, The Brain as an Organ of Mind, c. x. contains a history of theories of Phrenology and Localization. Cf. also the article "Brain" in Chambers' Encyclopedia (Edit. 1888); "Physiology," Encyc. Brit. (9th Edit. 1885); Calderwood's Relations of Mind and Brain, pp. 77-122 Ladd, op. cit. Pt. II. cc. i. ii. (1887); Foster, Text-book Physiology (1895). Pt. III. c. ii. §§ 7-9 Surbled, Le Cerveau (Paris: Retaux. Bray, 1890); and W. von Bechterew, Bewussstsein und Hirnlokalisation. (Leipsic, 1898.) The most considerable recent original work, however. is P. Flechsig's Gehirne und Seele. (Leipsic, 1896.)
{10} The proof of this is based on the fact that in creation the effect depends solely on the efficient cause. It is, therefore, the highest and noblest mode of action, and consequently must proceed from an agent endowed with the highest form of being -- self-existence. A creature cannot even play an instrumental part in creation; for the function of an instrument is to dispose and arrange the pre-existing materials, but antecedently to the creative act there are no such materials. Cf. Boedder, Natural Theology, pp. 126, seq.
{11} Lotze's defective view as to the nature of substance leads him into a similar error. Dr. Martineau's work, A Study of Religion, p. 334 (and Edit.), has some good observations on this point.
{12} See Harper's Metaphysics of the School. Vol. II. pp. 553-565. Having shown that St. Thomas's teaching of a "progressive development of being" in all embryonic life is in harmony with the most recent physiological science, he urges that "this theory serves to throw light on the perfection of the cosmic order. . . . For, the truth of the teaching for which we are contending once admitted, not only must we acknowledge a gradual evolution of the whole complex and multiform universe of material substances from a few simple elements created in the beginning; but it is also manifest that this wondrous evolution is, so to say, more or less epitomized in the germ-history of each living individual in that universe. Successive Forms march through the captive Matter gradually evolved from the predisposed Subject; till they reach their climax where the potentiality of Matter fails, and the creative power of God supplies the needed Form." (p. 560.)
{13} Philosophy of the Mind, pp. 363, 364.