Aristotle, Nicomachean Ethics
H. Rackham, Ed.

but to those things in regard to which a man can be profligate; and also it does not mean merely that he is concerned with these things （for in that case Unrestraint would be the same thing as Profligacy）, but that he is concerned with them in a particular manner. The profligate yields to his appetites from choice, considering it right always to pursue the pleasure that offers, whereas the man of defective self-restraint does not think so, but pursues it all the same.3. [3]

（i） Now the suggestion that it is not Knowledge, but True Opinion, against which unrestrained men act, is of no importance for our argument. Some men hold their opinions with absolute certainty, and take them for positive knowledge; 3. [4] so that if weakness of conviction be the criterion for deciding that men who act against their conception of what is right must be said to opine rather than to know the right, there will really be no difference in this respect between Opinion and Knowledge; since some men are just as firmly convinced of what they opine as others are of what they know: witness Heracleitus.¹ 3. [5]

（1） But the word know is used in two senses. A man who has knowledge but is not exercising it is said to know, and so is a man who is actually exercising his knowledge. It will make a difference whether a man does wrong having the knowledge that it is wrong but not consciously thinking of his knowledge, or with the knowledge consciously present to his mind. The latter would be felt to be surprising; but it is not surprising that a man should do what he knows to be wrong if he is not conscious of the knowledge at the time.