o
the apprehensive part: for Augustine says (De Nat. Boni xx) that
"bodily pain is caused by the sense resisting a more powerful body."
Therefore pain is not a passion of the soul.

Obj. 3: Further, every passion of the soul belongs to the animal
appetite. But pain does not belong to the animal appetite, but rather
to the natural appetite; for Augustine says (Gen. ad lit. viii, 14):
"Had not some good remained in nature, we should feel no pain in
being punished by the loss of good." Therefore pain is not a passion
of the soul.

_On the contrary,_ Augustine (De Civ. Dei xiv, 8) reckons pain among
the passions of the soul; quoting Virgil (Aeneid, vi, 733):

"hence wild desires and grovelling fears
And human laughter, human tears."
[Translation: Conington.]

_I answer that,_ Just as two things are requisite for pleasure;
namely, conjunction with good and perception of this conjunction; so
also two things are requisite for pain: namely, conjunction with some
evil (which is in so far evil as it deprives one of some good), and
perception of this conjunction. Now whatever is conjoined, if it have
not the aspect of good or evil in regard to the being to which it is
conjoined, cannot cause pleasure or pain. Whence it is evident that
something under the aspect of good or evil is the object of the
pleasure or pain. But good and evil, as such, are objects of the
appetite. Consequently it is clear that pleasure and pain belong to
the appetite.

Now every appetitive movement or inclination consequent to
apprehension, belongs to the intellective or sensitive appetite:
since the inclination of the natural appetite is not consequent to an
apprehension of the subject of that appetite, but to the apprehension
of another, as stated in the First Part (Q. 103, AA. 1, 3). Since
then pleasure and pain presuppose some sense or apprehension in the
same subject, it is evident that pain, like pleasure, is in the
intellective or sensitive appetite.

Again every movement of the sensitive appetite is called a passion,
as stated above (Q. 22, AA. 1, 3): and especially those which tend to
some defect. Consequently pain, according as it is in the sensitive
appetite, is most properly called a passion of the soul: just as
bodily ailments are properly called passions of the body. Hence
Augustine (De Civ. Dei xiv, 7, 8 [*Quoting Cicero]) reckons pain
especially as being a kind of ailment.

Reply Obj. 1: We speak of the body, because the cause of