I answer that, Sins take their species from their objects, as stated above (FS, Question [72], Article [1]). Now the object of a sin is the good towards which an inordinate appetite tends. Hence where there is a special aspect of good inordinately desired, there is a special kind of sin. Now the useful good differs in aspect from the delightful good. And riches, as such, come under the head of useful good, since they are desired under the aspect of being useful to man. Consequently covetousness is a special sin, forasmuch as it is an immoderate love of having possessions, which are comprised under the name of money, whence covetousness [avaritia] is denominated.
Since, however, the verb "to have," which seems to have been originally employed in connection with possessions whereof we are absolute masters, is applied to many other things (thus a man is said to have health, a wife, clothes, and so forth, as stated in De Praedicamentis), consequently the term "covetousness" has been amplified to denote all immoderate desire for having anything whatever. Thus Gregory says in a homily (xvi in Ev.) that "covetousness is a desire not only for money, but also for knowledge and high places, when prominence is immoderately sought after." In this way covetousness is not a special sin: and in this sense Augustine speaks of covetousness in the passage quoted in the First Objection. Wherefore this suffices for the Reply to the First Objection.
