dy may be so tended, as to be capable of the due performance of
its functions. The latter question lies in the province of
Medicine, the former in the province of Logic. Here, therefore,
I repeat, I shall treat only of the power of the mind, or of
reason; and I shall mainly show the extent and nature of its
dominion over the emotions, for their control and moderation.
That we do not possess absolute dominion over them, I have
already shown. Yet the Stoics have thought, that the emotions
depended absolutely on our will, and that we could absolutely
govern them. But these philosophers were compelled, by the
protest of experience, not from their own principles, to confess,
that no slight practice and zeal is needed to control and
moderate them: and this someone endeavoured to illustrate by the
example (if I remember rightly) of two dogs, the one a house--dog
and the other a hunting--dog. For by long training it could be
brought about, that the house--dog should become accustomed to
hunt, and the hunting--dog to cease from running after hares. To
this opinion Descartes not a little inclines. For he maintained,
that the soul or mind is specially united to a particular part of
the brain, namely, to that part called the pineal gland, by the
aid of which the mind is enabled to feel all the movements which
are set going in the body, and also external objects, and which
the mind by a simple act of volition can put in motion in various
ways. He asserted, that this gland is so suspended in the midst
of the brain, that it could be moved by the slightest motion of
the animal spirits: further, that this gland is suspended in the
midst of the brain in as many different manners, as the animal
spirits can impinge thereon; and, again, that as many different
marks are impressed on the said gland, as there are different
external objects which impel the animal spirits towards it;
whence it follows, that if the will of the soul suspends the
gland in a position, wherein it has already been suspended once
before by the animal spirits driven in one way or another, the
gland in its turn reacts on the said spirits, driving and
determining them to the condition wherein they were, when
repulsed before by a similar position of the gland. He further
asserted, that every act of mental volition is united in nature
to a certain given motion of the gland. For instance, whenever
anyone desires to look at a remote object, the act of volition
cau