ourteous and disdainful, may readily conform
to usage in his language, and even in his personal sentiments, without
taking either too seriously: he is not struggling to free his own mind,
which is free already, nor very hopeful of freeing that of most people.
The innate ideas were not explicit thoughts but categories employed
unwittingly, as people in speaking conform to the grammar of the
vernacular without being aware that they do so. As for extension being the
essence of matter, since matter existed and was a substance, it would
always have been more than its essence: a sort of ether the parts of which
might move and might have different and calculable dynamic values. The
gist of this definition of matter was to clear the decks for scientific
calculation, by removing from nature the moral density and moral magic
with which the Socratic philosophy had encumbered it. Science would be
employed in describing the movements of bodies, leaving it for the senses
and feelings to appreciate the cross-lights that might be generated in the
process. Though not following the technique of Descartes, the physics of
our own day realises his ideal, and traces in nature a mathematical
dynamism, perfectly sufficient for exact prevision and mechanical art.

Similarly, in saying that the essence of the soul was to think, Descartes
detached consciousness, or actual spirit, from the meshes of all unknown
organic or invented mental mechanisms. It was an immense clarification and
liberation in its proper dimension: but this pure consciousness was not a
soul; it was not the animal psyche, or principle of organisation, life,
and passion--a principle which, according to Descartes, was material. To
have called such a material principle the soul would have shocked all
Christian conceptions; but if Descartes had abstained from giving that
consecrated name to mere consciousness, he need not have been wary of
making the latter intermittent and evanescent, as it naturally is. He was
driven to the conclusion that the soul can never stop thinking, by the
desire to placate orthodox opinion, and his own Christian sentiments, at
the expense of attributing to actual consciousness a substantial
independence and a directive physical force which were incongruous with
it: a force and independence perfectly congruous with the Platonic soul,
which had been a mythological being, a supernatural spirit or daemon or
incubus, incarnate in the natural world, and partly d