Necessarium fuit habitus esse, quia habitus sunt perfectiones quaedam, ut dicitur in VII Physic, sed perfectio est maxime necessaria rei, cum habeat rationem finis.
It is necessary that there should be habits, because habits are perfections (Phys. vii, text. 17), and perfection is of the greatest necessity to a thing, since it has the formal aspect of purpose.
Sicut supra dictum est, habitus importat dispositionem quandam in ordine ad naturam rei, et ad operationem vel finem eius, secundum quam bene vel male aliquid ad hoc disponitur.
As we have said above (q49 a2, a3), habit implies a disposition in ordination to a thing's nature, and [a disposition] to its operation or purpose, [and], according to [this disposition], something is well- or ill-disposed to that [operative purpose].
Non idem habitus se habet ad bonum et malum, sicut infra patebit. Eadem autem potentia se habet ad bonum et malum. Et ideo necessarii sunt habitus ut potentiae determinentur ad bonum.
The same habit has not a relation to good and evil, as will be made clear further on (q54 a3): whereas the same power has a relation to good and evil. And, therefore, habits are necessary that potentials be determined to the good.