But thou sayest “I am not of this sort in my bodily frame, or my turn of mind.” That is for want, not of power, but of will. For thus I prove that all have a certain aptness towards virtue: That which a man cannot do, neither will he be able to do though necessity be laid upon him; but, if, necessity being laid upon him, he is able, he that leaveth it undone, leaveth it undone out of choice. The kind of thing I mean is this: to fly up and be borne towards heaven, having a heavy body, is even simply impossible. What then, if a king should command one to do this, and threaten death, saying, “Those men who do not fly, I decree that they lose their heads, or be burnt, or some other such punishment:” would any one obey him? Surely not. For nature is not capable of it. But if in the case of chastity this same thing were done, and he were to lay down laws that the unclean should be punished, be burnt, be scourged, should suffer the extremity of torture, would not many obey the law? “No” thou wilt say: “for there is appointed, even now, a law forbidding to commit adultery and all do not obey it.” Not because the fear looses its power, but because the greater part expect to be unobserved. So that if when they were on the point of committing an unclean action the legislator and the judge came before them, the fear would be strong enough to cast out the lust. Nay, were I to apply another kind of force inferior to this; were I to take the man and remove him from the beloved person, and shut him up close in chains, he will be able to bear it, without suffering any great harm. Let us not say then that such an one is by nature evil: for if a man were by nature good, he could never at any time become evil; and if he were by nature evil, he could never be good. But now we see that changes take place rapidly, and that men quickly shift from this side to the other, and from that fall back again into this. And these things we may see not in the Scriptures only, for instance, that publicans have become apostles; and disciples, traitors; and harlots, chaste; and robbers, men of good repute; and magicians have worshipped; and ungodly men passed over unto godliness, both in the New Testament and in the Old; but even every day a man may see many such things occurring. Now if things were natural, they could not change. For so we, being by nature susceptible, could never by any exertions become void of feeling. For that which is whatever it is by nature, can never fall away from such its natural condition. No one, for example, ever changed from sleeping to not sleeping: no one from a state of corruption unto incorruption: no one from hunger to the perpetual absence of that sensation. Wherefore neither are these things matters of accusation, nor do we reproach ourselves for them; nor ever did any one, meaning to blame another, say to him, “O thou, corruptible and subject to passion:” but either adultery or fornication, or something of that kind, we always lay to the charge of those who are responsible; and we bring them before judges, who blame and punish, and in the contrary cases award honors.