Freedom is secured not by the fulfillment of one's desires, but by the removal of desire.
Man is not worried by real problems so much as by his imagined anxieties about real problems
Act well your given part; the choice rests not with you.
You may fetter my leg, but Zeus himself cannot get the better of my free will.
If a man is unhappy, remember that his unhappiness is his own fault, for God made all men to be happy.
Appearances to the mind are of four kinds. Things either are what they appear to be; or they neither are, nor appear to be; or they are, and do not appear to be; or they are not, and yet appear to be. Rightly to aim in all these cases is the wise man's task.