Since therefore felicity is the use of virtue in prosperity, we must speak concerning virtue and prosperity, and in the first place concerning prosperity. For of goods, some indeed do not admit of excess, and this is the case with virtue. For there is not any virtue which is excessive, nor any worthy man who is beyond measure good. For virtue has the fit and becoming for a rule, and is the habit of the decorous in practical concerns. But prosperity receives excess and diminution. And when it is excessive indeed, it generates certain vices, and removes a man from his natural habit; so that he frequently through this opposes the constitution of virtue. And this is not only the case with prosperity, but many other causes likewise may effect the same thing. For it is by no means proper to wonder, that some of those who play on the pipe should be arrogant men, who, bidding farewell to truth, ensnare by a certain false imagination those who are unskilled in music; and to disbelieve that a thing of this kind does not take place in virtue. For the more venerable a thing is, so much the more numerous are those that pretend to the possession of it. For there are many things which distort the habit and form of virtue; some of which are insidious arts and affectation; others are kindred physical passions, which sometimes produce an indecorum[63] contrary to the true disposition [of virtue.] This also is effected through manners in which men have been nurtured for a long time; and it not unfrequently happens that it is produced through youth or old age, and through prosperity or adversity; and by other very numerous ways. Hence, we ought never to wonder, if sometimes a distorted judgment is formed of all things, the true disposition being changed.[64] Thus we see that the most excellent carpenter frequently errs in the works which are the subjects of his art; and this is also the case with the general, the pilot, the painter, and in short, with all artists. And yet at the same time we do not deprive them of the habit which they possess. For as we do not rank among bad men him who at certain times acts intemperately, or unjustly, or timidly; so neither do we place him in the class of good men, who does something right in things pertaining to temperance, or justice, or fortitude. But it must be said that the conduct of bad men in things of this kind is casually right, and that good men [sometimes] err. A true judgment however [in these instances] is to be formed, not by looking to a certain occasion, or to a certain extent of time, but to the whole of life. But as indigence and excess are injurious to the body, yet excess and what are called superfluities, are naturally adapted to produce greater diseases [than those caused by indigence]; thus also prosperity or adversity injure the soul, when they unseasonably happen; yet that which is called by all men prosperity, is naturally adapted to produce greater diseases