difference of habits is not a pure privation, but something
determinate repugnant to a determinate nature.

Reply Obj. 3: Several good habits about one same specific thing are
distinct in reference to their suitability to various natures, as
stated above. But several bad habits in respect of one action are
distinct in reference to their diverse repugnance to that which is in
keeping with nature: thus, various vices about one same matter are
contrary to one virtue.
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FOURTH ARTICLE [I-II, Q. 54, Art. 4]

Whether One Habit Is Made Up of Many Habits?

Objection 1: It would seem that one habit is made up of many habits.
For whatever is engendered, not at once, but little by little, seems
to be made up of several parts. But a habit is engendered, not at
once, but little by little out of several acts, as stated above
(Q. 51, A. 3). Therefore one habit is made up of several.

Obj. 2: Further, a whole is made up of its parts. Now many parts are
assigned to one habit: thus Tully assigns many parts of fortitude,
temperance, and other virtues. Therefore one habit is made up of many.

Obj. 3: Further, one conclusion suffices both for an act and for a
habit of scientific knowledge. But many conclusions belong to but one
science, to geometry, for instance, or to arithmetic. Therefore one
habit is made up of many.

_On the contrary,_ A habit, since it is a quality, is a simple form.
But nothing simple is made up of many. Therefore one habit is not
made up of many.

_I answer that,_ A habit directed to operation, such as we are
chiefly concerned with at present, is a perfection of a power. Now
every perfection should be in proportion with that which it perfects.
Hence, just as a power, while it is one, extends to many things, in
so far as they have something in common, i.e. some general objective
aspect, so also a habit extends to many things, in so far as they are
related to one, for instance, to some specific objective aspect, or
to one nature, or to one principle, as was clearly stated above (AA.
2, 3).

If then we consider a habit as to the extent of its object, we shall
find a certain multiplicity therein. But since this multiplicity is
directed to one thing, on which the habit is chiefly intent, hence it
is that a habit is a simple quality, not composed to several habits,
even though it extend to many things. For a habit does not extend to
many things save in relation to one, whence it derive