f vice to the irascible
faculty, not by reason of hatred, which is properly a concupiscible
passion; but on account of the struggle, which belongs to the
irascible power.

Reply Obj. 3: Good, inasmuch as it is delightful, moves the
concupiscible power. But if it prove difficult to obtain, from this
very fact it has a certain contrariety to the concupiscible power:
and hence the need of another power tending to that good. The same
applies to evil. And this power is the irascible faculty.
Consequently the concupiscible passions are specifically different
from the irascible passions.
________________________

SECOND ARTICLE [I-II, Q. 23, Art. 2]

Whether the Contrariety of the Irascible Passions Is Based on the
Contrariety of Good and Evil?

Objection 1: It would seem that the contrariety of the irascible
passions is based on no other contrariety than that of good and evil.
For the irascible passions are ordained to the concupiscible
passions, as stated above (A. 1, ad 1). But the contrariety of the
concupiscible passions is no other than that of good and evil; take,
for instance, love and hatred, joy and sorrow. Therefore the same
applies to the irascible passions.

Obj. 2: Further, passions differ according to their objects; just as
movements differ according to their termini. But there is no other
contrariety of movements, except that of the termini, as is stated in
_Phys._ v, 3. Therefore there is no other contrariety of passions,
save that of the objects. Now the object of the appetite is good or
evil. Therefore in no appetitive power can there be contrariety of
passions other than that of good and evil.

Obj. 3: Further, "every passion of the soul is by way of approach and
withdrawal," as Avicenna declares in his sixth book of _Physics._
Now approach results from the apprehension of good; withdrawal, from
the apprehension of evil: since just as "good is what all desire"
(Ethic. i, 1), so evil is what all shun. Therefore, in the passions
of the soul, there can be no other contrariety than that of good and
evil.

_On the contrary,_ Fear and daring are contrary to one another, as
stated in _Ethic._ iii, 7. But fear and daring do not differ in
respect of good and evil: because each regards some kind of evil.
Therefore not every contrariety of the irascible passions is that of
good and evil.

_I answer that,_ Passion is a kind of movement, as stated in _Phys._
iii, 3. Therefore contrariety of passions is base