17. And in sum, it is necessary to restrain young men from the conversation of debauched persons, lest they take infection from their evil examples. This was taught by Pythagoras in certain enigmatical sentences, which I shall here relate and expound, as being greatly useful to further virtuous inclinations. Such are these. Taste not of fish that have black tails; that is, converse not with men that are smutted with vicious qualities. Stride not over the beam of the scales; wherein he teacheth us the regard we ought to have for justice, so as not to go beyond its measures. Sit not on a choenix; wherein he forbids sloth, and requires us to take care to provide ourselves with the necessaries of life. Do not strike hands with every man; he means we ought not to be over hasty to make acquaintances or friendships with others. Wear not a tight ring; that is, we are to labor after a free and independent way of living, and to submit to no fetters. Stir not up the fire with a sword; signifying that we ought not to provoke a man more when he is angry already (since this is a most unseemly act), but we should rather comply with him while his passion is in its heat. Eat not thy heart; which forbids to afflict our souls, and waste them with vexatious cares. Abstain from beans; that is, keep out of public offices, for anciently the choice of the officers of state was made by beans. Put not food in a chamber-pot; wherein he declares that elegant discourse ought not to be put into an impure mind; for discourse is the food of the mind, which is rendered unclean by the foulness of the man who receives it. When men are arrived at the goal, they should not turn back; that is, those who are near the end of their days, and see the period of their lives approaching, ought to entertain it contentedly, and not to be grieved at it.