Aristotle, Nicomachean Ethics
H. Rackham, Ed.

Moreover the case of the arts is not really analogous to that of the virtues. Works of art have their merit in themselves, so that it is enough if they are produced having a certain quality of their own; but acts done in conformity with the virtues are not done justly or temperately if they themselves are of a certain sort, but only if the agent also is in a certain state of mind when he does them: first he must act with knowledge¹; secondly he must deliberately choose the act, and choose it for its own sake; and thirdly the act must spring from a fixed and permanent disposition of character. For the possession of an art, none of these conditions is included, except the mere qualification of knowledge; but for the possession of the virtues, knowledge is of little or no avail, whereas the other conditions, so far from being of little moment, are all-important, inasmuch as virtue results from the repeated performance of just and temperate actions.