as distinct from the universal, aspect of thought is foremost with him, then biological or physical analogies are apt to obtrude. The plant assimilates the material in a material manner, sense assimilates the material in an immaterial manner and thought assimilates the immaterial in an immaterial manner1." we miss in Aristotle is a clear recognition of what we now call consciousness as the central feature of all psychical facts. Regarding these facts as he did from the outside rather than from within, from the circumference rather than from the centre, he failed to find an adequate unity for the diverse functions which he described; he had to rest content with the biological conception of an organism, into which, however, he infused a strong teleological colouring. Descartes' Psychology of the thinking mind. § 2. When we pass to the psychology of Descartes we are at the opposite extreme. The connexion of body and mind, the corner-stone of Aristotle's construction, was the chief stumblingblock in the way of Descartes' advance, and has remained as a perplexing problem even to our own day. The hazy materialism, into which the Aristotelian psychology had developed in mediaeval times, Descartes banished once for all by the new definitions which he gave of matter and mind. Both were substances and therefore essentially distinct: the essence of matter was extension or the occupation of space, that of mind. was consciousness; and between these there was no common term and there was no natural connexion. Cogito, ergo sum, Descartes began: I think, therefore I am.' This was for him the primal certainty, the starting-point alike of his philosophy and of his psychology. "By the word thought (cogitatio)," he tells us, "I understand all that which so takes place in us that we of ourselves immediately apperceive it; and that is why, accordingly, not only understanding, willing, imagining, but also sensing (sentire, sentir) are here the same thing as thinking (cogitare, penser). For if I say, I see or I walk, and therefrom infer that I am; and if I understand by seeing or walking the action of my eyes or my legs, which is the work of 1 Bäumker, Des Aristoteles Lehre u.s. w., quoted by Wallace, Aristotle's Psychology, p. lvi. the body, the conclusion is not absolutely certain.... Whereas if I mean only the action of my consciousness or sensation itself, that conclusion is so absolutely certain as to exclude all doubt, because it is then referred to the mind, which alone has the faculty of being conscious or sensing that I see or walk1." Here then we are unmistakably inside the circle which Aristotle regarded mainly from without, and the central unity which we missed in his exposition is now clearly indicated. Subjective psychology deals with whatever we are immediately conscious of as something taking place within us: with the biological aspects, the physical occasions, or the epistemological interpretation of this something, it has no concern. All that it essentially implies is a conscious individual (a res cogitans) and the various actions and passions of which it is conscious-'its diverse modes of thinking,' or 'the contents of its consciousness,' as some would say. So far from a body being necessary to the existence of a conscious mind, as Aristotle from his objective standpoint assumed and naturally, for it was with the living body that he began the distinctness and independence of the two are, Descartes maintained, at once evident so soon as we reflect on the nature of consciousness. We then "perceive clearly that neither extension nor figure nor local motion......pertains to our nature, and nothing save thought alone: it then becomes plain that I am not the assemblage of members called the human body; I am not a thin and penetrating air diffused through all these members, or wind, or flame, or vapour, or breath; for the notion we have of our mind precedes that of any corporeal thing, and is more certain, seeing we still doubt whether there is any body in existence, while we already perceive that we think?" This restriction of psychology to the immediate facts of consciousness as these exist for the conscious subject was a great advance on the confusion of psychology with biology which characterised the Aristotelian and scholastic doctrines. As a result, the science made more progress in two centuries than it had made in twenty centuries before. But as so often 1 Principles of Philosophy, pt. 1. § 9. In equating Descartes' cogitatio to the modern consciousness,' which is on the whole the best rendering, we must not forget the predominantly cognitive implication which it, even more than its present equivalent, always retains. 2 Principles, 1. 8, and Meditation, II. (Veitch's ed. p. 108). happens, the reaction-as we have already hinted-was excessive; this we shall see if we examine the Cartesian dualism a little further. Whereas Aristotle on the whole kept to facts, Descartes trusted to analytic distinctions. Aristotle found mind and body invariably connected, and therefore he regarded them as essentially inseparable. Descartes could conceive mind without body and body without mind; therefore he concluded that they were actually independent and could exist apart. But what sort of mind was it that Descartes thus conceived? Broadly speaking it was the human soul of Aristotle less the senses, memory and imagination which-on Aristotle's viewman shared with the lower animals and required as indispensable conditions of his own activity. The thought that essentially belonged to this soul apart from a body excluded everything we now call empirical: hence the dualism of pure thought and experience that reappeared in modern philosophy. This res cogitans of Descartes then, as such, could only be occupied with eternal truths or 'innate ideas' and with whatever other ideas it might itself frame from these: 'adventitious ideas' it would not have at all. But even at this point a little reflexion will convince us that such a consciousness as this Cartesian cogitatio is not really conceivable. It lacks individuality and it lacks concreteness. For the environment and the intercourse with other selveson which any consciousness of self depends—are so far wanting. In other words, as yet the conditions of actual experience are incomplete. Let us now turn for a moment to material substance, the second term in the Cartesian dualism. As sensations were not to be attributed to mind as res cogitans, so here sensible qualities are not to be attributed to matter as res extensa. Only so far as matter was "the object of speculative geometry" was its nature intelligible, and for this knowledge sensory experience was superfluous; nay, worse-it was misleading. Descartes' res extensa was thus even more than his res cogitans a merely analytical concept. There the concrete individual Cogito was at least a certainty; though one which the bare concept of mindsubstance did not explain. But here there is no corresponding certainty and the matter-substance is only differentiated into a plurality of concrete material things by a series of glaring subreptions and incongruities. In both cases the fault lay in his rationalistic attempt to derive the concrete facts of experience from purely abstract notions. Dynamical concepts, such as those of mass and force, which only experience could warrant, were smuggled without clear definition or derivation into a physics that professed to be 'nothing but geometry.' Yet in spite of these initial defects the impetus that Descartes gave to Natural Philosophy was even greater than that which we have allowed is owed to him by Mental Philosophy; and the achievement here again was due to his famous method. As he cleared the conception of consciousness of hazy materialistic implications so he cleared that of matter of the animism involved in the mediaeval notions of occult qualities such as the natural gravitation of earth, the natural levitation of air, nature's abhorrence of a vacuum, and the like. But the details of his Natural Philosophy do not now concern us: it is enough to recognise that in it mechanical notions were supreme throughout. An organism accordingly was for Descartes simply a mechanism, an integral part of the one vast mechanism called the external world. So far then from connecting biology with psychology, as Aristotle had done, Descartes reduced biology to physics. And now what of the connexion of body and mind? We note first of all that Descartes inverted the Aristotelian position that intellect presupposes sense1: according to him sense presupposed intellect. "I find in myself," he says, "the faculties of imagination and sensation (sentir), without which I can indeed clearly and distinctly conceive myself entire, but not reciprocally them without myself, that is to say, without an intelligent substance in which they reside, for...in their formal concept, they involve some sort of intellection." Finding further "not merely that brutes have less reason than man, but that they have none at all," he concluded that they were nothing but automatic machines, entirely comparable-save for their greater complexity -to the contrivances of a skilful clockmaker, needing, as he expressly said, "neither a vegetative soul, nor a sensitive soul." Even the human body, physically regarded, was only such a machine. 1 So far, that is, as Aristotle did assume it. Nevertheless the relation of man's soul to his body was not comparable to that of a pilot in a seaworthy boat: after all the two become a single substantial unity:-" Me non tantum adesse meo corpori, ut nauta adest navigio, sed illi arctissime esse conjunctum et quasi permixtum, adeo, ut unum quid cum illo componam'." But how was such substantial unity possible? To answer this question reason was helpless; and even the criterion, on which Descartes' whole method of philosophising was founded, proved at fault. This he frankly owned. "To me it seems impossible," he writes, "that the human mind should, distinctly and at the same time, conceive the distinctness of body and soul and likewise their union; for so to do, it must conceive them as a single thing while yet conceiving them as two, which is selfrepugnant." Yet Descartes never denied that the unity was at any rate a fact, however inexplicable, and a fact that rendered human experience possible. Nay, strange to say and in spite of his general rejection of final causes, Descartes concludes his Meditations by pointing out-in the style of a Bridgewater treatise the mutual adaptability of body and mind manifested in our daily experiences. He concludes by laying down the maxim:-"I ought not in the least degree to doubt of the truth of those presentations [' of my body surrounded by many other bodies'], if, after having called together all my senses, my memory, and my understanding for the purpose of examining them, no deliverance is given by any one of these faculties which is repugnant to that of any other." But on the senses exclusively, as Descartes allowed, we depend for the knowledge that material things actually exist; and it is equally certain— though this he did not explicitly allow-that but for memory we should be without that knowledge of our own existence, from which he started. Both sensation and memory, however, belong to man only as a rational animal, not to man conceived as intellectus purus. In other words, intellect alone is not the source of our real experience. But it is the source of the concepts of res cogitans and res extensa as disparate and mutually independent substances, the concepts, that is to say, on which the 1 Meditation, VI., Veitch, p. 160. But in view of the importance of this passage it seems worth while to give the original. 2 Letter to the Princess Elizabeth, June, 1643. 3 Meditation, VI., Veitch, p. 168. |