7. The same reflections may be made about pain, and one's feeling of
it. When a man's finger is said to give him pain, this, no doubt,
is a recognition that the seat of the pain is in the finger, and
that the feeling of pain is experienced by the directing principle.
Consequently, when a part of the spirit suffers, this suffering is felt
by the directing principle, and shared by the whole soul.[56] How can
this sympathy be explained? By relay transmission, (the Stoic) will
answer; the sense-impression is felt first by the animal spirit that
is in the finger, and then transmitted to the neighboring part, and
so on till it reaches the directing part. Necessarily, if the pain is
felt by the first part that experiences it, it will also be felt by the
second part to which it is transmitted; then by the third, and so on,
until the one pain would have caused an infinite number of sensations.
Last the directing principle will perceive all these sensations, adding
thereto its own sensation. Speaking strictly, however, each of these
sensations will not transmit the suffering of the finger, but the
suffering of one of the intermediate parts. For instance, the second
sensation will relay the suffering of the hand. The third, that of
the arm, and so on, until there will be an infinity of sensations.
The directing principle, for its part, will not feel the pain of the
finger, but its own; it will know none but that, it will pay no
attention to the rest, because it will ignore the pain suffered by the
finger. Therefore, relayed sensation is an impossibility, nor could
one part of the body perceive the suffering felt by another part; for
the body has extension, and, in every extension, parts are foreign to
each other (the opposite of the opinion of Cleanthes, Nemesius).[57]
Consequently, the principle that feels must everywhere be identical
with itself; and among all beings, the body is that which is least
suitable to this identity.