3.21.1
They who have taken up bare theorems ( θεωρήματα ) immediately wish to vomit them forth, as persons whose stomach is diseased do with food. First digest the thing, then do not vomit it up thus: if you do not digest it, the thing becomes truly an emetic, a crude food and unfit to eat. But after digestion show us some change in your ruling faculty, as athletes show in their shoulders by what they have been exercised and what they have eaten; as those who have taken up certain arts show by what they have learned. The carpenter does not come and say, Hear me talk about the carpenter's art; but having undertaken to build a house, he makes it, and proves that he knows the art. You also ought to do something of the kind; eat like a man, drink like a man, dress, marry, beget children, do the office of a citizen, endure abuse, bear with an unreasonable brother, bear with your father, bear with your son, neighbour, companion. Show us these things that we may see that you have in truth learned something from the philosophers. You say, No; but come and hear me read (philosophical) commentaries. Go away, and seek somebody to vomit them on. (He replies) And indeed I will expound to you the writings of Chrysippus as no other man can: I will explain his text most clearly: I will add also, if I can, the vehemence of Antipater and Archedemus.