Jacques Maritain Center :
Psychology / by Michael Maher, S.J.Scope of Rational Psychology. -- We have hitherto been chiefly studying the character of our several mental activities, and the modes of their exercise; we now pass on to inquire into the nature of the principle from which they proceed. The aim of Rational, Metaphysical, or Philosophical Psychology, is to penetrate to the souce of the phenomena of consciousness. It endeavours to ascertain the inner constitution of the subject of our psychical states, and to discover the relations subsisting between this subject and the body. In a word, Philosophical Psychology seeks to learn what may be gathered by the light of reason regarding the nature, origin, and destiny of the human soul.
Its Importance. -- The importance of such a study is evident. What are we? Whence come we? How ought we to live? What is there to hope for? These have ever been questions of transcendent interest to mankind; and never more so than at the present day. Beside these problems, unless in so far as they may throw light on them, the discussions of Empirical Psychology sink into comparative insignificance. Yet the great majority of recent English text-books on Psychology affect to ignore these matters altogether. Or, if they allude to them, they do so with a shame-faced profuseness of apology which is not a little amusing. The naturalist, the physiologist, the physicist, may speculate at length about the nature and future destiny of man's soul; but if a writer on the Science of the Human Mind ventures to touch on topics so alien to his subject and so unbecoming his character, unless, indeed, in order to show that there is no soul and no future, his reputation as a psychologist is at once ruined, and he is stigmatized as a "metaphysician"! The unsatisfactoriness of such a course ought now to be plain to our readers. The first part of this work, whatever be its positive value, ought to have at least proved that it is impossible to separate the investigation of our mental activities from Philosophy -- that an unphilosophical psychology is necessarily an inconsistent, and therefore an unscientific psychology. Our views concerning the existence of an external world, the nature of the higher faculties of the soul, human responsibility, causality, and the final question of materialism or spiritualism, must inevitably he determined by the view of the character of mental life adopted in the empirical portion of Psychology. Once more we are forced to choose, not between a metaphysical psychology and psychology without any metaphysics; but between a psychology annexed to an inconsistent, half-concealed, clandestine metaphysics, and one that forms part of a philosophical system which, whatever be its difficulties, is at any rate openly professed and frankly declared.
Method. -- Our method of procedure here will be both inductive and deductive, both analytic and synthetic. We start from truths and facts already possessed to reach others not yet known. We argue from the effect to the cause. From the character of those mental activities, which we have analyzed with so much care, we shall now be able to perfect our conception of the subject to which they belong. We believe that no doctrine concerning the nature of the soul can be satisfactorily established in the face of modern criticism, based, as it now is, on most acute and elaborate analyses of our conscious states, unless that doctrine rest upon an analysis of these states not less thorough and painstaking. And it is for this reason, we have begun this work by so laborious and detailed an investigation into the character of our mental activities, especially those of thought and volition. From what the mind does, we shall now seek to learn what it is. From the spiritual nature of our rational and voluntary operations, we shall show that the soul is endowed with the attributes of simplicity and spirituality; or rather, that in its nature it is a simple spiritual substantial being. When this all-important truth has been firmly established, we shall deduce certain other conclusions regarding the soul's origin and destiny. It will, however, be most convenient to begin by proving the soul to be a substantial principle. We shall then establish its persisting indivisible identity through life; next its simple nature; and afterwards its spirituality. Each of these propositions, taken by itself, may afford but little positive information; and even when they have been all combined, the synthetic concept of the nature of the soul thus reached will still necessarily be very imperfect and inadequate; nevertheless, it will constitute knowledge real and valid, so far as it goes.
Substantiality of the Human Mind or Soul. -- By the word Mind or Soul, we here understand the subject of our mental life, the ultimate principle by which we feel, think, and will. A principle is that from which something proceeds, and by ultimate principle is here meant the last ground or source of the mental activity within us. Our immediate task, therefore, is to prove that this ultimate principle of our individual conscious life is of a substantial nature. The notion of Substance has been so violently attacked in modern philosophy that it is desirable in entering upon the present question to add some further remarks to the account already given of this idea when dealing with its genesis. (See p. 368.) But for a detailed discussion of the subject we must refer to the volume of this series on Metaphysics.
Validity of Notion of Substance. -- All being is divided into substance and accidents. Substance is that which exists per se -- that which subsists in itself; as contrasted with accident, that which of its nature inheres in another as in a subject of inhesion. The primary element therefore in the concept of Substance is not permanence amid change, although in the development of the notion this feature plays an important part. Still less is the essential note of substance the idea of a secret substratum, concealed like "the core of an onion" beneath a rind of changing accidents really distinct from itself. The Divine Being, though devoid of all accidents and immutable from all eternity, is a perfect Substance; and on the other hand, an atom or an angel created to be destroyed the next instant, would have been a genuine substance, even if it underwent no change during its brief existence. The assault of modern philosophy upon the conception of substance has been almost entirely directed against this secret substratum or noumenon which is supposed never to reveal itself to cognition. Accordingly, when we recall and insist upon the old definition -- id quod per se stat, -- the most plausible objections which have been raised against this notion lose their force.{1}
The Mind is a Substantial Principle. -- Every form of reality must in the last resort either subsist in itself, that is, exist per se, or inhere in another being. Sphericity, colour, pain, for instance, cannot subsist in themselves; neither can there be an infinite series of such accidents, each being only a mode or attribute of another; there must ultimately be something which exists per se. Furthermore, substances really act, and by their action make themselves known to us. Now the last ground of our mental life, the ultimate basis of our psychical activities must be a substantial principle. States of consciousness, mental modifications, necessarily presuppose a subject to which they belong. Even assuming that they may turn out to be functions of the nervous system, or phases or aspects of cerebral processes, they must still have their origin in a substantial principle. Motion is unthinkable without something that is moved. A feeling necessarily implies a being which feels. Cognitions and passions cannot inhere in nothing. Desires cannot proceed from nothing; they must have a source or a subject from which they flow. So far even the materialist must agree with us.
Internal Experience. -- Or we may appeal directly to the testimony of internal consciousness. That I am a real being, subsisting in myself; that I am immediately aware of myself as the subject of sensations, feelings, and thoughts, but not any one of them, or all of them; that I am the cause of my own volitions; that I am distinct from other beings; that there is in me a Self -- that I am an Ego which is the centre and source of my acts and states, the ultimate ground and subject of my thoughts and affections, is forced upon me by constant, intimate, immediate self-experience, with the most irresistible evidence. If it be an illusion, there is no belief, no cognition, however clear and certain, that can claim assent. Notwithstanding his own erroneous view as to the nature of Substance, Lotze rightly insists that the cognition of a substantial self, is a fact of immediate experience: "It has been required of any theory which starts without presuppositions and from the basis of experience, that in the beginning it should speak only of sensations and ideas, without mentioning the soul to which, it is said, we hasten without justification to ascribe them. I should maintain, on the contrary, that such a mode of setting out involves a wilful departure from that which is actually given in experience. A mere sensation without a subject is nowhere to be met with as a fact. It is impossible to speak of a bare movement without thinking of the mass whose movement it is; and it is just as impossible to conceive a sensation existing without the accompanying of that which has it, -- or rather, of that which feels it, for this also is included in the given fact of experience that the relation of the feeling subject to its feeling, whatever its other characteristics may be, is in any case something different from the relation of the moved element to its movement. It is thus and thus only, that the sensation is a given fact; and we have no right to abstract from its relations to its subject because this relation is puzzling, and because we wish to obtain a starting-point which looks more convenient, but is utterly unwarranted by experience." (Metaphysic, § 241.)
Abiding Identity of the Mind. -- Having insisted on the truth that the primary note in the concept of substance is not the idea of a permanent secret immutable substratum; we now proceed to prove that, as a matter of fact, the substantial being of the human mind does endure throughout our mental life -- that the soul is a real unitary being which abides the same during all the varying modes of consciousness. And, although permanence amid changing accidents is not necessarily implied in the notion of substance, the establishment of the present proposition will undoubtedly tend to render still more evident the substantial nature of the Mind. The proof rests on the evidence of internal consciousness, understanding this term in a broad sense, so as to include reflective-cognition and self-conscious memory.
Reflexion and Memory. -- Any process of reflective observation of our experiences brings into the most vivid contrast the distinction between the mind as an abiding subject and its transitory modifications, whilst it forces upon us the real sameness of that subject with an evidence that is irresistible. The simplest act of judgment, the briefest process of conscious reasoning is possible only to a being that persists unchanged during the interval required to pass from subject to predicate, from premisses to conclusions. But the necessary continuity of the agent becomes more obvious in the exercise of deliberate recollection. Memory, in a certain sense, is involved in every retrospective operation; indeed, it is an essential condition of every act of knowledge which extends beyond the mere present sensation; but the assurance it affords concerning some past experiences is not less than that which we possess in regard to present events. I am indubitably certain that I rose from bed this morning, that I breakfasted, that I have written the first words of the sentence which I am now continuing, that I was in Liverpool last winter, and the like. When I now turn to analyze introspectively these remembrances, I perceive that they all implicitly involve the identification of my present self with the self of these past experiences. But this would be impossible were the mind merely a succession of states, or were the material organism the substantial principle in which these states inhere. The constituent elements of the latter, it is a well-established physiological fact, are completely changed in a comparatively short time; and fleeting mental acts which did not inhere in a permanent subject, could as little result in this self-conscious recollection, as could the disconnected cognitions of successive generations of men. The unity of consciousness establishes an essential unity of being. It is only a real unitary being, persisting the same amid transitory states, that can afford an adequate basis for the fact of remembrance. Margerie, therefore, rightly maintains: "The condition necessary for the act of recollection, is the identity of the being who remembers, with that being whose former states are recalled by memory. To remember experiences of another would be to remember having been somebody else: in other words, to simultaneously affirm and deny one's own identity, a pure and absurd contradiction."{2}
Apart, however, from memory, self-consciousness, strictly understood, discloses to me only the present existence of the Ego in my various operations. It does not reveal my past history, nor assure me of the identity of the man sitting here with the boy who was at a certain school many years ago. Mistake is therefore possible with respect to some past events owing to accidental aberrations of memory. But this in no way invalidates our argument. A single certain recollection would be sufficient to prove the persisting identity of the mind as a real being. Lotze has written well: "We come to understand the connexion of our inner life only by referring all its events to the one Ego lying unchanged alike beneath its simultaneous variety and its temporal succession. Every retrospect of the past brings with it this image of the Ego as the combining centre; our ideas, our feelings, our efforts are comprehensible to us only as its states or energies, not as events floating unattached in a void. And yet we are not incessantly making this reference of the internal manifold to the unity of the Ego. It becomes distinct only in the backward look which we cast over our life with a certain concentration of collective attention. . . . It is not necessary and imperative that at every moment and in respect to all its states a Being should exercise the unifying efficiency put within its power by the unity of its nature. . . . If the soul, even if but rarely, but to a limited extent, nay, but once be capable of bringing together variety into the unity of consciousness, this slender fact is sufficient to render imperative an inference to the indivisibility of the Being by which it can be performed."{3}
Simplicity of the Soul. -- In establishing the permanent identity of the mind we have proved that it is not composed of a series of successive events or states. By affirming its simplicity we mean to affirm that it is not composed of separate parts or diverse principles of any kind; consequently that it is not extended.{4} The method of proof is the same -- from the indivisible unity of consciousness; and the present proposition is really demonstrated by the last argument. But the impossibility of the ultimate source of our conscious life being a composite substance will become clearer if we consider the character of some particular mental acts, and try to realize what is involved in the supposition that they proceed from such a substance.
(1) The Simplicity of Intellectual Ideas. -- Our experience teaches us that we can form various abstract ideas, such as those of Being, Unity, Truth, Virtue, and the like, which are of their nature simple indivisible acts. Now, acts of this sort cannot proceed from an extended or composite substance, such as, for instance, the brain. This will be seen by a little reflexion. In order that the indivisible idea of, say, Truth, be the result of the activity of this extended substance, either different parts of the idea must belong to different parts of the brain, or each part of the brain must be subject of an entire idea, or the whole idea must pertain to a single part of the brain. The first alternative is clearly absurd. The act by which the intellect apprehends virtue, being, and the like, is an indivisible thought. It is directly incompatible with its nature to be allotted or distributed over an aggregate of separate atoms. But the second alternative is equally impossible. If different parts of the composite substance were each the basis of a complete idea, we should have at the same time not one, but several ideas of the object. Our consciousness, however, tells us this is not the case. Lastly, if the whole idea were located in one part or element of the composite substance, this part should itself be composite or simple. If the latter, then our thesis -- that the ultimate subject of thought is indivisible -- is established at once. If the former, then the old series of impossible alternatives will recur again until we are finally forced to the same conclusion.
(2) The Simplicity of the Intellectual Acts of Judgment and Inference. -- A similar line of reasoning applies here. The simplest judgment supposes the comparison of two distinct ideas, which must be simultaneously apprehended by one indivisible agent. Suppose the judgment, "Science is useful," to be elicited. If the Subject which apprehends the two concepts "science" and "useful" is not indivisible, then we must assume that one of these terms is apprehended by one part and the other by a second; or else that separate elements of the divisible Subject are each the seat of both ideas. In the former case, however, we cannot have any judgment at all. The part a apprehends "science," the different part b conceives the notion "useful," but the indivisible act of comparison requiring a single agent who combines the two ideas is wanting, and we can no more have the affirmative predication than if one man thinks "science," and another forms the concept "useful." In the second alternative, if a and b each simultaneously apprehended both "science" and "useful," then we should have not one but a multiplicity of judgments. The simplicity of the inferential act by which we seize the logical sequence of a conclusion, is still more irreconcilable with the hypothesis of a composite Subject. The three judgments -- Every y is z; every z is y; therefore, every x is z -- could no more constitute a syllogism if they proceeded from a composite substance than if each proposition was apprehended alone by a separate man.
This good old argument has also been adopted by Lotze: "Any comparison of two ideas, which ends by our finding their contents like or unlike, presupposes the absolutely indivisible unity of that which compares them; it must be one and the same thing which first forms the idea of a, and then that of b, and which at the same time is conscious of the nature and extent of the difference between them. Then again the various acts of comparing ideas and referring them to one another are themselves in turn reciprocally related; and this relation brings a new activity of comparison to consciousness. And so our whole inner world of thoughts is built up, not as a mere collection of manifold ideas existing with or after one another, but as a work in which these individual members are held together and arranged by the relating activity of this single pervading principle. This is what we mean by the Unity of Consciousness. It is this we regard as sufficient ground for assuming an indivisible soul."{5}
(5) The Indivisibility of Volition. -- The same line of argument as in the case of judgment establishes the simplicity of the soul from the unity of consciousness presented in acts of will. An indivisible act of choice cannot be elicited by an assemblage of distinct parts or principles.{6} But we may leave the development of the proof to the reader.
We have thus shown that the soul cannot be formally extended, that it cannot have parts outside of parts after the manner of a material substance. But this does not exclude the possibility of what is sometimes termed virtual extension -- that attribute in virtue of which an energy indivisible in itself may yet exert its influence throughout an extended sphere.
The Spirituality of the Soul. -- We now pass on to demonstrate that the soul is spiritual or immaterial. The attribute of spirituality is sometimes confounded with that of simplicity, but they ought to be carefully distinguished. By saying that a substance is simple we mean that it is not a resultant or product of separate factors or parts. By affirming that it is spiritual or immaterial, we signify that in its existence, and to some extent in regard to its operations, it is independent of matter. The principle of life in the lower animals was held by the schoolmen to be in this sense an example of a simple principle which is nevertheless not spiritual, since it is altogether dependent upon the organism, or, as they said, completely immersed in the body. St. Thomas, accordingly, speaks of the corporeal souls of brutes.
The Human Soul is a Spiritual Substance. -- The proof may be stated briefly thus: The human soul is the subject or source of various spiritual activities; but the subject or source of spiritual activities must be itself a spiritual being; therefore the soul must be a spiritual being. The minor premiss is merely a particular application of the axiom, that the operation of an agent follows its nature -- actio sequitur esse. As the being is, so must it act. The establishment of the general truth of this principle is a problem for Metaphysics; but all that is necessary for our purpose becomes evident on a little careful consideration of the axiom. An effect cannot transcend its cause: no action can contain more perfection or a higher order of reality than is possessed by the being which is the entire source of that action. If, then, a mental activity can be shown not to be exerted by a material organ, or to be in any degree independent of a material organ, the principle from which that activity proceeds must be similarly independent. It is positively unthinkable that whilst the soul depended as regards its whole being on the organism, it should still in some of its exercises be in any way independent of the organism. If, accordingly, any activities of the soul are spiritual, then the soul itself is spiritual.{7} For the proof of the proposition that we are endowed with activities of a spiritual or immaterial kind we have only to refer to the results established in chapters xii. and xix. where we showed both Intellect and Will to be intrinsically independent of the body. We shall, however, here recall some of the facts which manifest the truth of our thesis:
1. The Spirituality of Thought . -- We are capable of apprehending and representing to ourselves abstract and universal ideas, such as justice, unity, man, triangle; we can form notions of spiritual being, e.g., of God; we can understand necessary truths; we can comprehend possibilities as such; and we can perceive the rational relations between ideas, and the logical sequence of conclusion from premisses. But we have shown that such operations as these are spiritual phenomena, which must accordingly proceed from a spiritual faculty. They could not be states of a faculty exerted through, or intrinsically dependent on, a bodily organ. A power of this kind can only react in response to physical impressions, and can only form representations of a concrete character, depicting contingent individual facts. But universality, possibility, logical sequence, general relations, do not constitute such a physical stimulus, and consequently could not be apprehended by an organic faculty. Accordingly, these higher mental functions must be admitted to be of a spiritual character; they thus transcend the sphere of all actions depending intrinsically or essentially by their nature on a material instrument.
This same argument is recently adopted by as competent an authority on cerebral physiology as Professor Ladd. He thus writes: "The existence which we call 'the mind' is never known -- even when observed in its most exalted states and in the exercise of its most spiritual activities -- as released wholly from bodily functions. . . . At the same time, in all forms of knowledge, and especially in self-knowledge, with its equipment of realized aesthetical and ethical sentiments, and of self-conscious choices, the mind manifests and knows itself as manifesting an existence in some sort independent of the bodily organism. With no mere figure of speech we are compelled to say, every mind thus transcends completely, not only the powers of the cerebral mechanism by springing into another order of phenomena, but also the very existence, as it were, of that mechanism by passing into regions of space, time, causality, and ideality, of various kinds, where the terms that apply to the existence and activity of the cerebral centres have absolutely no meaning whatever. For example, the human mind anticipates the future and predicts, on a basis of experience in the past, the occurrences which will be but are not now. Into this future, which is itself the product of its own imagining and thinking, it projects its own continued and yet characteristically altered existence, as well as the continued similar existence of things. But the existence of the brain, and of its particular forms of nerve commotion, is never other than a purely here-and-now existence. This physical existence is, therefore, transcended in an absolute way by every such activity of the mind. Moreover, all supra-sensuous knowledge, as such, enforces the same conviction as to a potential independency of the mind, inferred upon the basis of an actual experience with mental activities in the way of transcending the sphere of the correlated being and activities of the brain. For all (supra-sensuous?) knowledge is of the universal. In knowing, the mind moves in the sphere of so-called 'law,' of 'genera,' and 'species,' of 'relations common' to many individuals, of the 'categories,' of the true for all spaces and all times and all circumstances. But the existence of the brain is never more than concrete and individual; its being is at every instant precisely such and no other -- so many countless atoms of oxygen, hydrogen, nitrogen, &c., combined in precisely such proportions."{8}
2. Self-Consciousness. -- The reflex operation exhibited in the act of self-consciousness, is also of a spiritual or supra-organic order, and cannot be the activity of a faculty essentially dependent on a corporeal agent. The peculiar nature of this aptitude, so fundamentally opposed in kind to all the properties of matter, has been already gone into at such length (pp. 238-242), that we can afford but little space for the subject here. We shall, however, call attention to that aspect of this familiar phenomenon which has often been recognized by thoughtful minds to be the most wonderful fact in the universe. In the act of self-consciousness there occurs an instance of the complete or perfect reflexion of an indivisible agent back on itself. I recognize an absolute identity between myself thinking about something, and myself reflecting on that thinking Self. The Ego reflecting and the Ego reflected upon is the same: it is at once subject and object. An action of this sort is not merely unlike the known qualities of bodies: it stands in direct and open conflict with all the most fundamental characteristics of matter. It is in absolute contradiction with the essential nature of matter. One part of a material substance may be made to act upon another, one atom may attract, repel, or in various ways influence another, but the assumption that one atom can act upon itself -- that precisely the same portion of matter can be agent and patient in its own case -- is repugnant to all that either common experience or physical science teaches us. If then this unity of agent and patient, of subject and object, is so contrary to the nature of matter, assuredly an activity every element of which is intrinsically dependent on a corporeal organ cannot be capable of self-reflexion.
3. The Will. -- The interest attached to the discussion of the freedom of the will is chiefly due to the bearing of that doctrine on the nature of the human mind. If any of man's volitions are free, if they are not the outcome of the forces playing upon him, then there must be within him an inner centre of causality, an internal agent, a nucleus of energy, enjoying at least a limited independence of the organism. The argument based on voluntary action may, however, start from two distinct points of view:
(a) A merely sentient agent -- one whose whole being is immersed in material conditions -- can only desire sensible goods. It can only seek what is proportioned to its nature, and this is always reducible to organic pleasure or avoidance of pain. On the other hand, to a spiritual creature which is endowed also with inferior faculties, both sensuous and supra-sensuous good is adapted. Therefore, the aspirations of the latter are unlimited, while those of the former are confined within the sphere of material well-being. But our own consciousness, history, biography, and the existence of poetry and romance, all overwhelm us with evidence of the fact that man is moved by supra-sensible good. Love of justice, truth, virtue, and right for its own sake, are motives and impulses which have inspired some of the greatest and noblest works chronicled in the narrative of the human race. Consequently, there must be in man a principle not completely subject to material conditions.
(b) Again: we are free; we are capable of self-determination; but no organic faculty can determine itself. Such an action, as we have already insisted, is repugnant to the essential nature of matter. On the other hand, were our volitions not spiritual, were they, as our opponents allege, merely subjective phases or mental states inseparably bound up with organic processes; did they not proceed from a principle in some degree independent of matter, their moral freedom would be impossible; and man would be devoid of responsibility and incapable of morality.
{1} "The chief attack on substance is made precisely on the misconception, that the inmost essence of the notion is a substratum, hidden away under qualities really distinct from itself, a fixed unchangeable thing clothed in attributes, some variable, some constant, but all, as was just said, really distinct. Such is the interpretation of the scholastic theory by most opponents; while the schoolmen themselves have held up existence per se as the fundamental notion of substance. For, first it is clear that they could apply no other definition to God. Moreover, even with regard to created substance, they were aware of the enormous philosophic difficulty in the proof of what are sometimes called 'absolute accidents that are more than merely modal,' for the demonstration of which they relied not on arguments from reason, but upon consequences which they thought to be involved in the Church's doctrine about the Holy Eucharist." (John Rickaby, Metaphysics, p. 254.) "Permanence is not of the essence of substance, any more than non-permanence or succession of accidents is of their essence; Kant, therefore, and Green are wrong in the leading position which they assign to permanence." (Ibid. p. 259.)
{2} Philosophie Contemporaine, p. 140.
{3} Microcosmus, Bk. II. C. i. § 4. The student must be careful not to conceive the unity of consciousness in this sense as opposed to the doctrine of the ultimate duality of consciousness in External Perception. (Cf. p. 106.)
{4} The schoolmen expressed this attribute. -- absence of extension or composition of integrant parts -- by the term quantitative simplicity. The fact that the soul is not the result of a plurality of principles coalescing to form a single nature (as e.g., in their view the formal and material principles of all corporeal objects) they signified by asserting that it is essentially simple -- simplex quoad essentiam. Our proof equally excludes all forms of composition, that of extended parts as well as that of separate unextended principles, whether homogeneous or heterogeneous. The unity of consciousness is incompatible with a multiplicity of component elements, of whatever kind.
{5} Metaphysics. § 241. Cf. Balmez, op. cit. Bk. XI. c. ii.; also our citation, pp. 245-247.
{6} Cf. Margerie, pp. 15, seq.; and Balmez, op. cit. Bk. IX. § 76,
{7} Cf. Coconnier: "L'opération suit l être et lui est proportionnée . . . M. Büchner reconnaît formellement la valeur de cette formule, quand il écrit: La théorie positiviste est forcée de convenir que l'effet doit répondre à la cause, et qu'ainsi des effets compliqués doivent supposer, à un certain degré, des combinaisons de matières compliquées.' M. Karl Vogt . . . quand il dit: 'Encore faut il pourtant qua la fonction soit proportionelle à l'organisation et mesurée par elle.' M. Wundt . . . quand il dit: 'Nous ne pouvons mesurer directement ni les causes productrices des phénoménes, ni les forces productrices des mouvements, mais nous pouvons les mesurer par leurs effets.' C'est à dire qu'aujourd'hui comme autrefois tout le monde reconnait qu'on peut juger de la nature d'un être par son operation. Telle operation, telle nature; tel effet, telle cause; telle fonction, tel organe; tel mouvement, telle force; telle manière d'agir, telle manière d'être. Ainsi parlent, dans tous les siècles et par tout pays, la raison et la science. Donc, si un être a une opération à laquelle seul il s'élève, à laquelle seul il puisse atteindre, qu'il accomplisse comme agent isolé, dégagé libre, transcendant, cet être doit avoir une existence transcendante libre dégagée et qui appartienne en propre à sa nature. Or, en regardant l'âme humaine, je lui trouva une semblable operation; je lui vois, à un moment, cette manière d'agir libre, transcendante degagée de la matière. . . . C'est quand l'âme humaine pense, et quand elle prend conscience d'élle-même et de sa pensée." (L'Ame humaine, Existence et Nature, pp. 123-125.)
{8} Philosophy of Mind, pp. 400, 401.