ἃ πάσχοντες ὑφʹ ἑτέρων ὀργίζεσθε, ταῦτα τοὺς ἄλλους μὴ ποιεῖτε. - Isocrates

Be more careful in guarding against censure than against danger; for the wicked may well dread the end of life, but good men should dread ignominy during life. Strive by all means to live in security, but if ever it falls to your lot to face the dangers of battle, seek to preserve your life, but with honour and not with disgrace; for death is the sentence which fate has passed on all mankind, but to die nobly is the special honour with nature has reserved for the good.

Always when you are about to say anything, first weigh it in your mind; for with many the tongue outruns the thought. Let there be but two occasions for speech — when the subject is one which you thoroughly know and when it one on which you are compelled to speak. On these occasions alone is speech better than silence; on all others, it is better to be silent than to speak.

I shall be most grateful to the gods if I am not disappointed in the opinion which I have of you. For, while we find that the great majority of other men seek the society of those friends who join them in their follies and not of those to admonish them, just as they prefer the most pleasant to the most wholesome, you, I think, are minded otherwise as I judge from the industry you display in your general education. For when one sets for himself the highest standard of conduct, it is probable that in his relation to others he will approve only of those who exhort him to virtue. But most of all you would be spurred on to strive for noble deeds if you should realize that it is from them most of all that we also derive pleasure in the true sense. For while the result of indolence and love of surfeit is that pain follows on the heels of pleasure, on the other hand, devoted toil in the pursuit of virtue, and self-control in the ordering of one's life always yield delights that are pure and more abiding. In the former case we experience pain following upon pleasure, in the latter we enjoy pleasure after pain.