nor cynology could hope to be universal—the world is not all sheep nor all dog: it would have to be hylology; for the world is, in its spatial aspect, all material. Let us say, then, that there is one uniform material nature of things, and that everything else consists in the arrangements of the basic material nature; as the show of towers and mountains in the sunset results simply from an arrangement of vapours. And let us suppose that the interactions of the parts of matter are all like those which we can observe in dead manipulable bodies—in mechanism, in fact. Such was the postulate of the new philosophers, and it yielded them results.

It yielded them results, and that was highly gratifying. But what, meanwhile, had happened to those palpable facts of common experience from which the whole philosophy of substantial forms had taken its rise? Is the wholeness of a living thing the mere resultant of the orderly operations of its parts? Is a bee no more essentially one than a swarm is? Is the life of a living animal indistinguishable from the rhythm of a going watch, except in degree of complication and subtlety of contrivance? And if an animal's body, say my own, is simply an agglomerate of minute interacting material units, and its wholeness is merely accidental and apparent, how is my conscious mind to be adjusted to it? For my consciousness appears to identify itself with that whole vital pattern which used to be called the substantial form. We are now told that the pattern is nothing real or active, but the mere accidental resultant of distinct interacting forces: it does no work, it exercises no influence or control, it is nothing. How then can it be the vehicle and instrument of my conscious soul? It cannot. Then is my soul homeless? Or is it to be identified with the activity and fortunes of a single atomic constituent of my body, a single cog in the animal clockwork? If so, how irrational! For the soul does not experience itself as the soul of one minute part, but as the soul of the body.

Such questions rose thick and fast in the minds of the seventeenth-century philosophers. It will cause us no great surprise that Leibniz should have quickly felt that the Formal Principle of Aristotle and of the Scholastic philosophy must be by hook or by crook reintroduced—not as the detested substantial form, but under a name by which it might hope to smell more sweet, entelechy.

Nothing so tellingly revealed the difficulties of the new philosophy

in dealing with living bodies as the insufficiency of the solutions Descartes had proposed. He had boldly declared the unity of animal life to be purely mechanical, and denied that brutes had souls at all, or any sensation. He had to admit soul in man, but he still denied the substantial unity of the human body. It was put together like a watch, it was many things, not one: if Descartes had lived in our time, he would have been delighted to compare it with a telephone system, the nerves taking the place of the wires, and being so arranged that all currents of 'animal spirit' flowing in them converged upon a single unit, a gland at the base of the brain. In this unit, or in the convergence of all the motions upon it, the 'unity' of the body virtually consisted; and the soul was incarnate, not in the plurality of members (for how could it, being one, indwell many things?), but in the single gland.

Even so, the relation between the soul and the gland was absolutely unintelligible, as Descartes disarmingly confessed. Incarnation was all very well in the old philosophy: those who had allowed the interaction of disparate natures throughout the physical world need find no particular difficulty about the special case of it provided by incarnation. Why should not a form of conscious life so interact with what would otherwise be dead matter as to 'indwell' it? But the very principle of the new philosophy disallowed the interaction of disparate natures, because such an interaction did not allow of exact formulation, it was a 'loose' and not a 'tight' relation.

From a purely practical point of view the much derided pineal gland theory would serve. If we could be content to view Descartes as a man who wanted to make the world safe for physical science, then there would be a good deal to be said for his doctrine. In the old philosophy exact science had been frustrated by the hypothesis of loose relations all over the field of nature. Descartes had cleared them from as much of the field as science was then in a position to investigate; he allowed only one such relation to subsist, the one which experience appeared unmistakably to force upon us—that between our own mind and its bodily vehicle. He had exorcized the spirits from the rest of nature; and though there was a spirit here which could not be exorcized, the philosophic conjurer had nevertheless confined it and its unaccountable pranks within a minutely narrow magic circle: all mind could do

was to turn the one tiny switch at the centre of its animal telephone system. It could create no energy—it could merely redirect the currents actually flowing.

Practically this might do, but speculatively it was most disturbing. For if the 'loose relation' had to be admitted in one instance, it was admitted in principle; and one could not get rid of the suspicion that it would turn up elsewhere, and that the banishment of it from every other field represented a convenient pragmatic postulate rather than a solid metaphysical truth. Moreover, the correlation of the unitary soul with the unitary gland might do justice to a mechanistical philosophy, but it did not do justice to the soul's own consciousness of itself. The soul's consciousness is the 'idea' or 'representation' of the life of the whole body, certainly not of the life of the pineal gland nor, as the unreflective nowadays would say, of the brain. I am not conscious in, or of, my brain except when I have a headache; consciousness is in my eyes and finger-tips and so on. It is physically true, no doubt, that consciousness in and of my finger-tips is not possible without the functioning of my brain; but that is a poor reason for locating the consciousness in the brain. The filament of the electric bulb will not be incandescent apart from the functioning of the dynamo; but that is a poor reason for saying that the incandescence is in the dynamo.

Certainly the area of representation in our mind is not simply equivalent to the area of our body. But in so far as the confines of mental representation part company with the confines of the body, it is not that they may contract and fall back upon the pineal gland, but that they may expand and advance over the surrounding world. The mind does not represent its own body merely, it represents the world in so far as the world affects that body or is physically reproduced in it. The mind has no observable natural relation to the pineal gland. It has only two natural relations: to its body as a whole and to its effective environment. What Descartes had really done was to pretend that the soul was related to the pineal gland as it is in fact related to its whole body; and then that it was related to the bodily members as in fact it is related to outer environment. The members became an inner environment, known only in so far as they affected the pineal gland; just as the outer environment in its turn was to be known only in so far as it affected the members.

This doctrine of a double environment was wholly artificial. It was forced on Descartes by the requirements of mechanistical science: if the members were simply a plurality of things, they must really be parts of environment; the body which the soul indwelt must be a body; presumably, then, the pineal gland. An untenable compromise,