'He had better begin somewhat sooner.'

I mean this: When a carpenter is ill he asks the physician for a rough and ready cure; an emetic or a purge or a cautery or the knife,—these are his remedies. And if some one prescribes for him a course of dietetics, and tells him that he must swathe and swaddle his head, and all that sort of thing, he replies at once that he has no time to be ill, and that he sees no good in a life which is spent in nursing his disease to the neglect of his customary employment; and therefore bidding good-bye to this sort of physician, he resumes his ordinary habits, and either gets well and lives and does his business, or, if his consitution fails, he dies and has no more trouble. 

Yes, he [Glaucon] said, and a man in his condition of life ought to use the art of medicine thus far only. 

Has he not, I said, an occupation; and what profit would there be in his life if he were deprived of his occupation? 

Quite true, he said. 

But with the rich man this is otherwise; of him we do not say that he has any specially appointed work which he must perform, if he would live. 

He is generally supposed to have nothing do do. 

Then you never heard of the saying of Phocylides, that as soon as a man has a livelihood he should practise virtue? 

Nay, he said, I think that he had better begin somewhat sooner.

—Plato, The Republic, Book III (360 B.C.E.; trans. B. Jowett 1894)