participated is reduced to what is
essential. But things which are evil among us are evil not
essentially, but by participation. Therefore we must seek for
some supreme essential evil, which is the cause of every evil.

Obj. 5: Further, whatever is accidental is reduced to that which is
_per se._ But good is the accidental cause of evil. Therefore, we
must suppose some supreme evil which is the _per se_ cause of evils.
Nor can it be said that evil has no _per se_ cause, but only an
accidental cause; for it would then follow that evil would not exist
in the many, but only in the few.

Obj. 6: Further, the evil of the effect is reduced to the evil of the
cause; because the deficient effect comes from the deficient cause,
as was said above (AA. 1, 2). But we cannot proceed to infinity in
this matter. Therefore, we must suppose one first evil as the cause
of every evil.

_On the contrary,_ The supreme good is the cause of every being, as
was shown above (Q. 2, A. 3; Q. 6, A. 4). Therefore there cannot be
any principle opposed to it as the cause of evils.

_I answer that,_ It appears from what precedes that there is no one
first principle of evil, as there is one first principle of good.

First, indeed, because the first principle of good is essentially
good, as was shown above (Q. 6, AA. 3, 4). But nothing can be
essentially bad. For it was shown above that every being, as such,
is good (Q. 5, A. 3); and that evil can exist only in good as in
its subject (Q. 48, A. 3).

Secondly, because the first principle of good is the highest and
perfect good which pre-contains in itself all goodness, as shown above
(Q. 6, A. 2). But there cannot be a supreme evil; because, as was
shown above (Q. 48, A. 4), although evil always lessens good, yet
it never wholly consumes it; and thus, while good ever remains,
nothing can be wholly and perfectly bad. Therefore, the Philosopher
says (Ethic. iv, 5) that "if the wholly evil could be, it would
destroy itself"; because all good being destroyed (which it need be
for something to be wholly evil), evil itself would be taken away,
since its subject is good.

Thirdly, because the very nature of evil is against the idea of a
first principle; both because every evil is caused by good, as was
shown above (A. 1), and because evil can be only an accidental
cause, and thus it cannot be the first cause, for the accidental
cause is subsequent to the direct cause.

Those, however, who upheld two