Aristotle, Nicomachean Ethics
H. Rackham, Ed.

The difficulties that may be raised are the following. （c） How can a man fail in self-restraint when believing correctly that what he does is wrong? Some people say that he cannot do so when he knows the act to be wrong; since, as Socrates held, it would be strange if, when a man possessed Knowledge, some other thing should overpower it, and ‘drag it about like a slave.’¹ In fact Socrates used to combat the view² altogether, implying that there is no such thing as Unrestraint, since no one, he held, acts contrary to what is best, believing what he does to be bad, but only through ignorance. 2. [2] Now this theory is manifestly at variance with plain facts; and we ought to investigate the state of mind in question more closely. If failure of self-restraint is caused by ignorance, we must examine what sort of ignorance it is. For it is clear that the man who fails in self-restraint does not think the action right before he comes under the influence of passion.—2. [3] But some thinkers accept the doctrine in a modified form. They allow that nothing is more powerful than knowledge, but they do not allow that no one acts contrary to what he opines to be the better course; and they therefore maintain that the unrestrained man when he succumbs to the temptations of pleasure possesses not Knowledge but only Opinion. 2. [4] And yet if it is really Opinion and not Knowledge—not a strong belief