trary passion in that faculty, as stated above (Q.
23, A. 4). But no specific passion of the concupiscible faculty is
contrary to concupiscence. For Damascene says (De Fide Orth. ii, 12)
that "good when desired gives rise to concupiscence; when present, it
gives joy: in like manner, the evil we apprehend makes us fear, the
evil that is present makes us sad": from which we gather that as
sadness is contrary to joy, so is fear contrary to concupiscence. But
fear is not in the concupiscible, but in the irascible part.
Therefore concupiscence is not a specific passion of the
concupiscible faculty.

_On the contrary,_ Concupiscence is caused by love, and tends to
pleasure, both of which are passions of the concupiscible faculty.
Hence it is distinguished from the other concupiscible passions, as
a specific passion.

_I answer that,_ As stated above (A. 1; Q. 23, A. 1), the good which
gives pleasure to the senses is the common object of the
concupiscible faculty. Hence the various concupiscible passions are
distinguished according to the differences of that good. Now the
diversity of this object can arise from the very nature of the
object, or from a diversity in its active power. The diversity,
derived from the nature of the active object, causes a material
difference of passions: while the difference in regard to its active
power causes a formal diversity of passions, in respect of which the
passions differ specifically.

Now the nature of the motive power of the end or of the good, differs
according as it is really present, or absent: because, according as
it is present, it causes the faculty to find rest in it; whereas,
according as it is absent, it causes the faculty to be moved towards
it. Wherefore the object of sensible pleasure causes love, inasmuch
as, so to speak, it attunes and conforms the appetite to itself; it
causes concupiscence, inasmuch as, when absent, it draws the faculty
to itself; and it causes pleasure, inasmuch as, when present, it
makes the faculty to find rest in itself. Accordingly, concupiscence
is a passion differing _in species_ from both love and pleasure. But
concupiscences of this or that pleasurable object differ _in number._

Reply Obj. 1: Pleasurable good is the object of concupiscence, not
absolutely, but considered as absent: just as the sensible,
considered as past, is the object of memory. For these particular
conditions diversify the species of passions, and even of the powers
o