wrote in the seventeenth century. The long sleep of the
Middle Ages was past, and the several sciences had sprung into a
vigorous and independent life. It was not enough for Descartes to
describe the relation of mind and body in the loose terms that had
prevailed up to his time. He had made a careful study of anatomy, and
he realized that the brain is a central organ to which messages are
carried by the nerves from all parts of the body. He knew that an
injury to the nerve might prevent the receipt of a message, _i.e._ he
knew that a conscious sensation did not come into being until something
happened in the brain.

Nor was he content merely to refer the mind to the brain in a general
way. He found the "little pineal gland" in the midst of the brain to
be in what he regarded as an admirable position to serve as the seat of
the soul. To this convenient little central office he relegated it;
and he describes in a way that may to-day well provoke a smile the
movements that the soul imparts to the pineal gland, making it incline
itself in this direction and in that, and making it push the "animal
spirits," the fluid contained in the cavities of the brain, towards
various "pores."

Thus he writes:[1] "Let us, then, conceive of the soul as having her
chief seat in the little gland that is in the middle of the brain,
whence she radiates to all the rest of the body by means of the
spirits, the nerves, and even the blood, which, participating in the
impressions of the spirits, can carry them through the arteries to all
the members." And again: "Thus, when the soul wills to call anything
to remembrance, this volition brings it about that the gland, inclining
itself successively in different directions, pushes the spirits towards
divers parts of the brain, until they find the part which has the
traces that the object which one wishes to recollect has left there."

We must admit that Descartes' scientific studies led him to make this
mind that sits in the little pineal gland something very material. It
is spoken of as though it pushed the gland about; it is affected by the
motions of the gland, as though it were a bit of matter. It seems to
be a less inconsistent thing than the "all in the whole body" soul of
Plotinus; but it appears to have purchased its comprehensibility at the
expense of its immateriality.

Shall we say that Descartes frankly repudiated the doctrine that had
obtained for so many centuries? We cann