pain.

_I answer that,_ Evil, as was said above (A. 3), is the privation of
good, which chiefly and of itself consists in perfection and act. Act,
however, is twofold; first, and second. The first act is the form and
integrity of a thing; the second act is its operation. Therefore evil
also is twofold. In one way it occurs by the subtraction of the form,
or of any part required for the integrity of the thing, as blindness
is an evil, as also it is an evil to be wanting in any member of the
body. In another way evil exists by the withdrawal of the due
operation, either because it does not exist, or because it has not its
due mode and order. But because good in itself is the object of the
will, evil, which is the privation of good, is found in a special way
in rational creatures which have a will. Therefore the evil which
comes from the withdrawal of the form and integrity of the thing, has
the nature of a pain; and especially so on the supposition that all
things are subject to divine providence and justice, as was shown
above (Q. 22, A. 2); for it is of the very nature of a pain to be
against the will. But the evil which consists in the subtraction of
the due operation in voluntary things has the nature of a fault; for
this is imputed to anyone as a fault to fail as regards perfect
action, of which he is master by the will. Therefore every evil in
voluntary things is to be looked upon as a pain or a fault.

Reply Obj. 1: Because evil is the privation of good, and not a mere
negation, as was said above (A. 3), therefore not every defect of
good is an evil, but the defect of the good which is naturally due.
For the want of sight is not an evil in a stone, but it is an evil
in an animal; since it is against the nature of a stone to see. So,
likewise, it is against the nature of a creature to be preserved in
existence by itself, because existence and conservation come from one
and the same source. Hence this kind of defect is not an evil as
regards a creature.

Reply Obj. 2: Pain and fault do not divide evil absolutely
considered, but evil that is found in voluntary things.

Reply Obj. 3: Temptation, as importing provocation to evil, is always
an evil of fault in the tempter; but in the one tempted it is not,
properly speaking, a fault; unless through the temptation some change
is wrought in the one who is tempted; for thus is the action of the
agent in the patient. And if the tempted is changed to evil by the
tempter