A difficulty may however be raised as to what we mean by saying that in order to become just men must do just actions, and in order to become temperate they must do temperate actions. For if they do just and temperate actions, they are just and temperate already, just as, if they spell correctly or play in tune, they are scholars or musicians.
But perhaps this is not the case even with the arts. It is possible to spell a word correctly by chance, or because some one else prompts you; hence you will be a scholar only if you spell correctly in the scholar's way, that is, in virtue of the scholarly knowledge which you yourself possess.
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 knowledge * See Bk. 3.1, where this is interpreted as meaning both knowledge of what he is doing （the act must not be unconscious or accidental）, and knowledge of moral principle （he must know that the act is a right one）. ; 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.
Thus although actions are entitled just and temperate when they are such acts as just and temperate men would do, the agent is just and temperate not when he does these acts merely, but when he does them in the way in which just and temperate men do them.
It is correct therefore to say that a man becomes just by doing just actions and temperate by doing temperate actions; and no one can have the remotest chance of becoming good without doing them.
But the mass of mankind, instead of doing virtuous acts, have recourse to discussing virtue, and fancy that they are pursuing philosophy and that this will make them good men. In so doing they act like invalids who listen carefully to what the doctor says, but entirely neglect to carry out his prescriptions. That sort of philosophy will no more lead to a healthy state of soul than will the mode of treatment produce health of body.