Second Part: On Habits According to Moral Being, or On Acquired Virtues

According to moral being, that is, in order to the ultimate end and the rule of morals, operative habits are good and are virtues, or evil and are vices, according as they are suitable or not suitable to rational nature and its ultimate end.¹ Concerning vices enough has been said in the treatise on sins: for as many sins as there are diverse completed species, so many habits caused from them and inclining to them, or vices, can also be had. Therefore it remains that we speak specially of good habits and virtues.

¹ Moral theology treats of the motion of the rational creature toward God. We approach God by acts of virtues. Therefore virtues pertain per se to moral theology, not to dogmatic theology.