Whether Habit Increases by Addition?
Objection 1: It would seem that the increase of habits is by way of
addition. For the word "increase," as we have said, is transferred to
forms, from corporeal quantities. But in corporeal quantities there
is no increase without addition: wherefore (De Gener. i, text. 31) it
is said that "increase is an addition to a magnitude already
existing." Therefore in habits also there is no increase without
addition.
Obj. 2: Further, habit is not increased except by means of some
agent. But every agent does something in the passive subject: for
instance, that which heats, causes heat in that which is heated.
Therefore there is no increase without addition.
Obj. 3: Further, as that which is not white, is in potentiality to be
white: so that which is less white, is in potentiality to be more
white. But that which is not white, is not made white except by the
addition of whiteness. Therefore that which is less white, is not
made more white, except by an added whiteness.
_On the contrary,_ The Philosopher says (Phys. iv, text. 84): "That
which is hot is made hotter, without making, in the matter, something
hot, that was not hot, when the thing was less hot." Therefore, in
like manner, neither is any addition made in other forms when they
increase.
_I answer that,_ The solution of this question depends on what we
have said above (A. 1). For we said that increase and decrease in
forms which are capable of intensity and remissness, happen in one
way not on the part of the very form considered in itself, through
the diverse participation thereof by the subject. Wherefore such
increase of habits and other forms, is not caused by an addition of
form to form; but by the subject participating more or less
perfectly, one and the same form. And just as, by an agent which is
in act, something is made actually hot, beginning, as it were, to
participate a form, not as though the form itself were made, as is
proved in _Metaph._ vii, text. 32, so, by an intense action of the
agent, something is made more hot, as it were participating the form
more perfectly, not as though something were added to the form.
For if this increase in forms were understood to be by way of
addition, this could only be either in the form itself or in the
subject. If it be understood of the form itself, it has already been
stated (A. 1) that such an addition or subtraction would change the
species; even as the species of color is changed when a thing from
being pale becomes white. If, on the other hand, this addition be
understood as applying to the subject, this could only be either
because one part of the subject receives a form which it had not
previously (thus we may say cold increases in a man who, after being
cold in one part of his body, is cold in several parts), or because
some other subject is added sharing in the same form (as when a hot
thing is added to another, or one white thing to another). But in
either of these two ways we have not a more white or a more hot
thing, but a greater white or hot thing.
Since, however, as stated above (A. 1), certain accidents are of
themselves susceptible of more or less, in some of these we may find
increase by addition. For movement increases by an addition either to
the time it lasts, or to the course it follows: and yet the species
remains the same on account of the oneness of the term. Yet movement
increases the intensity as to participation in its subject: i.e. in
so far as the same movement can be executed more or less speedily or
readily. In like manner, science can increase in itself by addition;
thus when anyone learns several conclusions of geometry, the same
specific habit of science increases in that man. Yet a man's science
increases, as to the subject's participation thereof, in intensity,
in so far as one man is quicker and readier than another in
considering the same conclusions.
As to bodily habits, it does not seem very probable that they receive
increase by way of addition. For an animal is not said to be simply
healthy or beautiful, unless it be such in all its parts. And if it
be brought to a more perfect measure, this is the result of a change
in the simple qualities, which are not susceptible of increase save
in intensity on the part of the subject partaking of them.
How this question affects virtues we shall state further on (Q. 66,
A. 1).
Reply Obj. 1: Even in bodily bulk increase is twofold. First, by
addition of one subject to another; such is the increase of living
things. Secondly, by mere intensity, without any addition at all;
such is the case with things subject to rarefaction, as is stated in
_Phys._ iv, text. 63.
Reply Obj. 2: The cause that increases a habit, always effects
something in the subject, but not a new form. But it causes the
subject to partake more perfectly of a pre-existing form, or it makes
the form to extend further.
Reply Obj. 3: What is not already white, is potentially white, as not
yet possessing the form of whiteness: hence the agent causes a new
form in the subject. But that which is less hot or white, is not in
potentiality to those forms, since it has them already actually: but
it is in potentiality to a perfect mode of participation; and this it
receives through the agent's action.
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