ion 1: It would seem that good and evil in moral actions do not
make a difference of species. For the existence of good and evil in
actions is in conformity with their existence in things, as stated
above (A. 1). But good and evil do not make a specific difference in
things; for a good man is specifically the same as a bad man.
Therefore neither do they make a specific difference in actions.

Obj. 2: Further, since evil is a privation, it is a non-being. But
non-being cannot be a difference, according to the Philosopher
(Metaph. iii, 3). Since therefore the difference constitutes the
species, it seems that an action is not constituted in a species
through being evil. Consequently good and evil do not diversify the
species of human actions.

Obj. 3: Further, acts that differ in species produce different
effects. But the same specific effect results from a good and from an
evil action: thus a man is born of adulterous or of lawful wedlock.
Therefore good and evil actions do not differ in species.

Obj. 4: Further, actions are sometimes said to be good or bad from a
circumstance, as stated above (A. 3). But since a circumstance is an
accident, it does not give an action its species. Therefore human
actions do not differ in species on account of their goodness or
malice.

_On the contrary,_ According to the Philosopher (Ethic ii. 1) "like
habits produce like actions." But a good and a bad habit differ in
species, as liberality and prodigality. Therefore also good and bad
actions differ in species.

_I answer that,_ Every action derives its species from its object, as
stated above (A. 2). Hence it follows that a difference of object
causes a difference of species in actions. Now, it must be observed
that a difference of objects causes a difference of species in
actions, according as the latter are referred to one active
principle, which does not cause a difference in actions, according as
they are referred to another active principle. Because nothing
accidental constitutes a species, but only that which is essential;
and a difference of object may be essential in reference to one
active principle, and accidental in reference to another. Thus to
know color and to know sound, differ essentially in reference to
sense, but not in reference to the intellect.

Now in human actions, good and evil are predicated in reference to
the reason; because as Dionysius says (Div. Nom. iv), "the good of
man is to be in accordance with