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[19] 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.