Diogenes Laertius: Lives of Eminent Philosophers, Vol. 2 (Loeb)

nobility belongs to none other than the virtuous. And he held virtue to be sufficient in itself to ensure happiness, since it needed nothing else except the strength of a Socrates. He maintained that virtue is a matter of deeds and does not need a store of words or learning; that the wise man is self-sufficing, for all the goods of others are his; that ill repute is a good thing and much the same as pain; that the wise man will be guided in his public acts not by the established laws but by the law of virtue; that he will also marry in order to have children from union with the handsomest women; furthermore that he will not disdain to love, for only the wise man knows who are worthy to be loved.

Diocles records the following sayings of his: To the wise man nothing is foreign or impracticable. A good man deserves to be loved. Men of worth are friends. Make allies of men who are at once brave and just. Virtue is a weapon that cannot be taken away. It is better to be with a handful of good men fighting against all the bad, than with hosts of bad men against a handful of good men. Pay attention to your enemies, for they are the first to discover your mistakes. Esteem an honest man above a kinsman. Virtue is the same for women as for men. Good actions are fair and evil actions foul. Count all wickedness foreign and alien.

Wisdom is a most sure stronghold which never crumbles away nor is betrayed. Walls of defense must be constructed in our own impregnable reasonings. He used to converse in the gymnasium of Cynosarges (White hound) at no great distance from the gates, and some think that the Cynic school derived its name from Cynosarges.