Prosperity is no just scale; adversity is the only balance to weigh friends.

When a man's eyes are sore his friends do not let him finger them, however much he wishes to, nor do they themselves touch the inflammation: But a man sunk in grief suffers every chance comer to stir and augment his affliction like a running sore; and by reason of the fingering and consequent irritation it hardens into a serious and intractable evil.

Being conscious of having done a wicked action leaves stings of remorse behind it, which, like an ulcer in the flesh, makes the mind smart with perpetual wounds; for reason, which chases away all other pains, creates repentance, shames the soul with confusion, and punishes it with torment.

Music, to create harmony, must investigate discord.

When Demosthenes was asked what were the three most important aspects of oratory, he answered, 'Action, Action, Action.'

Neither blame or praise yourself.

Wise men are able to make a fitting use even of their enmities.