Aeschylus

The man whose authority is recent is always stern.

I know how men in exile feed on dreams.

Search well and be wise, nor believe that self-willed pride will ever be better than good counsel.

Destiny waits alike for the free man as well as for him enslaved by another's might.

For the poison of hatred seated near the heart doubles the burden for the one who suffers the disease; he is burdened with his own sorrow, and groans on seeing another's happiness.

And one who is just of his own free will shall not lack for happiness; and he will never come to utter ruin.

Happiness is a choice that requires effort at times.

It is good even for old men to learn wisdom.

He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God.

Wisdom comes alone through suffering.

Memory is the mother of all wisdom.

For somehow this disease inheres in tyranny, never to trust one's friends.