Reply Obj. 3:  The passion which is directly contrary to concupiscence has no name, and stands in relation to evil, as concupiscence in regard to good.  But since, like fear, it regards the absent evil; sometimes it goes by the name of fear, just as hope is sometimes called covetousness.  For a small good or evil is reckoned as though it were nothing:  and consequently every movement of the appetite in future good or evil is called hope or fear, which regard good and evil as arduous. ________________________

THIRD ARTICLE [I-II, Q. 30, Art. 3]

Whether Some Concupiscences Are Natural, and Some Not Natural?

Objection 1:  It would seem that concupiscences are not divided into those which are natural and those which are not.  For concupiscence belongs to the animal appetite, as stated above (A. 1, ad 3).  But the natural appetite is contrasted with the animal appetite.  Therefore no concupiscence is natural.

Obj. 2:  Further, material differences makes no difference of species, but only numerical difference; a difference which is outside the purview of science.  But if some concupiscences are natural, and some not, they differ only in respect of their objects; which amounts to a material difference, which is one of number only.  Therefore concupiscences should not be divided into those that are natural and those that are not.

Obj. 3:  Further, reason is contrasted with nature, as stated in Phys. ii, 5.  If therefore in man there is a concupiscence which is not natural, it must needs be rational.  But this is impossible:  because, since concupiscence is a passion, it belongs to the sensitive appetite, and not to the will, which is the rational appetite.  Therefore there are no concupiscences which are not natural.

On the contrary, The Philosopher (Ethic. iii, 11 and Rhetor. i, 11) distinguishes natural concupiscences from those that are not natural.

I answer that, As stated above (A. 1), concupiscence is the craving for pleasurable good.  Now a thing is pleasurable in two ways.  First, because it is suitable to the nature of the animal; for example, food, drink, and the like:  and concupiscence of such pleasurable things is said to be natural.  Secondly, a thing is pleasurable because it is apprehended as suitable to the animal:  as when one apprehends something as good and suitable, and consequently takes pleasure in it:  and concupiscence of such pleasurable things is said to be not natural, and is more wont to be called “cupidity.”

Accordingly concupiscences of the first kind, or natural concupiscences, are common to men and other animals:  because to both is there something suitable and pleasurable according to nature:  and in these all men agree; wherefore the Philosopher (Ethic. iii, 11) calls them “common” and “necessary.”  But concupiscences of the second kind are proper to men, to whom it is proper to devise something as good and suitable, beyond that which nature requires.  Hence the Philosopher says (Rhet. i, 11) that the former concupiscences are “irrational,” but the latter, “rational.”  And because different men reason differently, therefore the latter are also called (Ethic. iii, 11) “peculiar and acquired,” i.e. in addition to those that are natural.