"But," thou wilt say, "the bad have an ability." Nor do I wish to deny it; only this ability of theirs comes not from strength, but from impotence.

For their ability is to do evil, which would have had no efficacy at all if they could have continued in the performance of good.

So this ability of theirs proves them still more plainly to have no power.

For if, as we concluded just now, evil is nothing, 'tis clear that the wicked can effect nothing, since they are only able to do evil.' ''Tis evident.' 'And that thou mayst understand what is the precise force of this power, we determined, did we not, awhile back, that nothing has more power than supreme good ?' 'We did,' said I.
'But that same highest good cannot do evil ?' 'Certainly not.' 'Is there anyone, then, who thinks that men are able to do all things ?' 'None but a madman.' 'Yet they are able to do evil ?' 'Ay; would they could not!' 'Since, then, he who can do only good is omnipotent, while they who can do evil also are not omnipotent, it is manifest that they who can do evil have less power.

There is this also: we have shown that all power is to be reckoned among things desirable, and that all desirable things are referred to good as to a kind of consummation of their nature.