You might wonder why Aristotle is so interested in incontinence that he devotes the whole of Book VII of his Nichomachean Ethics to it. Is that really a problem for philosophers to worry about?
Well, it is, at least the kind of incontinence that Aristotle worries about.
The continent man is one "ready to abide by the result of his calculations" while the incontinent man is "ready to abandon them." Why does the continent man abide by his calculations? Because he knows "his appetites are bad, and refuses on account of his rational principles to follow them." The incontinent man, on the other hand, abandons his rational principles "as a result of passion."
But if you chop logic like the sophists, worries Aristotle, then you might end up unraveling your rational spaghetti into believing that "folly coupled with incontinence is virtue." For if continence makes a man stand by a false opinion, then it is good if an incontinent man, that abandons "any and every opinion", abandons a false opinion.
Aristotle briskly clears away the problem of this sophistical mirage, the virtuous incontinent, for he argues that the incontinent man is in the position of someone "having knowledge in a sense and yet not having it, as in the instance of a man asleep, mad, or drunk." He is like a city that "passes all the right decrees and has good laws, but makes no use of them". He is neither good nor bad, just a muddle.
But what about the continent man with the wrong opinion? Well, Aristotle says, these are likely strong-headed people, "hard to persuade in the first instance and not easily persuaded to change". This is to suggest that an continent man can be consumed with "passion and appetite". On the contrary, the "continent man will be easy to persuade". For being a man of rational principle, he is not led by his appetites and his pleasures, but readily bows to rational persuasion.
But let us not confuse the incontinent man with the self-indulgent. The first stands by his choice, and is not apt to repent his follies, while the incontinent man means well but is led astray by his passions. The self-indulgent man is "incurable and the incontinent curable." Think of the difference between dropsy and epilepsy, says Aristotle. The "former is a permanent, the latter an intermittent badness."
So that's all right!