n of God, superadded. The union of the soul or the
mind _(anima sive mens_) with the body is, it is true, not so loose that
the mind merely dwells in the body, like a pilot in a ship, nor, on the
other hand, in view of the essential contrariety of the two substances, is
it so intimate as to be more than a _unio compositionis_. Although the soul
is united to the whole body, an especially active intercourse between them
is developed at a single point, the pineal gland, which is distinguished by
its central, protected position, above all, by the fact that it is the only
cerebral organ that is not double. This gland, together with the animal
spirits passing to and from it, mediates between mind and body; and as the
point of union for the twofold impressions from the (right and left) eyes
and ears, without which objects would be perceived double instead of
single, is the seat of the soul. Here the soul exercises a direct influence
on the body and is directly affected by it; here it dwells, and at will
produces a slight, peculiar movement of the gland, through this a change
in the course of the animal spirits (for it is not capable of generating
motion, but only of changing its direction), and, finally, movements of the
members; just as, on the other hand, it remarks the slightest change in the
course of the _spiritus_ through a corresponding movement of the gland,
whose motions vary according to the sensuous properties of the object to be
perceived, and responds by sensations. Although Descartes thus limits the
direct interaction of soul and body to a small part of the organism, he
makes an exception in the case of _memoria_, which appears to him to be
more of a physical than a psychical function, and which he conjectures to
be diffused through the whole brain.

In spite of the comprehensive meaning which Descartes gives to the notion
_cogitatio_, it is yet too narrow to leave room for an _anima vegetativa_
and an _anima sensitiva_. Whoever makes mind and soul equivalent, holds
that their essence consists in conscious activity alone, and interprets
sensation as a mode of thought, cannot escape the paradox of denying to
animals the possession of a soul. Descartes does not shrink from such
a conclusion. Animals are mere machines; they are bodies animated, but
soulless; they lack conscious perception and appetition, though not the
appearance of them. When a clock strikes seven it knows nothing of the
fact; it does not regret that