Nicomachean Ethics VII.8

More on incontinence and repentance. 

The self-indulgent man, as was said, is not apt to repent; for he stands by his choice; but incontinent man is likely to repent. This is why the position is not as it was expressed in the formulation of the problem, but the self-indulgent man is incurable and the incontinent man curable; for wickedness is like a disease such as dropsy or consumption, while incontinence is like epilepsy; the former is a permanent, the latter an intermittent badness. And generally incontinence and vice are different in kind; vice is unconscious of itself, incontinence is not (of incontinent men themselves, those who become temporarily beside themselves are better than those who have the rational principle but do not abide by it, since the latter are defeated by a weaker passion, and do not act without previous deliberation like the others); for the incontinent man is like the people who get drunk quickly and on little wine, i.e. on less than most people.

This last analogy is a little ironic, because the kind of person who gets drunk quickly and on little wine is most likely to be the one who usually abstains completely. A tolerance is generally the product of practice, and the heavier the practice the greater the tolerance is likely to become.

Evidently, then, incontinence is not vice (though perhaps it is so in a qualified sense); for incontinence is contrary to choice while vice is in accordance with choice; not but what they are similar in respect of the actions they lead to; as in the saying of Demodocus about the Milesians, 'the Milesians are not without sense, but they do the things that senseless people do', so too incontinent people are not criminal, but they will do criminal acts.

This is similar to 'he is not a thief, but he stole' from V.6. Their developed character is slightly better, because they know what is right and know they ought to do it; yet the fact of the vicious or criminal act remains. (Why criminal? Because justice in Aristotle's ideal society demands that you take the action that a virtuous person would take, so if you do otherwise even through incompetence you will have broken a law.)

Now, since the incontinent man is apt to pursue, not on conviction, bodily pleasures that are excessive and contrary to the right rule, while the self-indulgent man is convinced because he is the sort of man to pursue them, it is on the contrary the former that is easily persuaded to change his mind, while the latter is not. For virtue and vice respectively preserve and destroy the first principle, and in actions the final cause is the first principle, as the hypotheses are in mathematics; neither in that case is it argument that teaches the first principles, nor is it so here-virtue either natural or produced by habituation is what teaches right opinion about the first principle. Such a man as this, then, is temperate; his contrary is the self-indulgent.

So we can see that the incontinent man is incompletely but partly virtuous, because he has the first principle that ought to govern his behavior and feels guilty about betraying it. The vicious man's first principle is destroyed and replaced with a vicious first principle instead: something like, 'I ought to get to take these pleasures because...' 

But there is a sort of man who is carried away as a result of passion and contrary to the right rule-a man whom passion masters so that he does not act according to the right rule, but does not master to the extent of making him ready to believe that he ought to pursue such pleasures without reserve; this is the incontinent man, who is better than the self-indulgent man, and not bad without qualification; for the best thing in him, the first principle, is preserved. And contrary to him is another kind of man, he who abides by his convictions and is not carried away, at least as a result of passion. It is evident from these considerations that the latter is a good state and the former a bad one.

We probably know more about the causes of all this than Aristotle did, but the basic structure still makes sense. You have people who do wrong, know it is wrong, and feel guilty about it; on their best days, they strive to do better, and on their worst days, they give in but regret it. You alternatively have people who joyously commit to doing wrong, enjoy getting away with it, and think it makes them better than other people that they can do such things while ordinary people are forbidden from it. One state is better than the other, though neither is perfectly good.