The health and vigor necessary for the practice of what is good, depend equally on both mind and body.

Protagoras asserted that there are two sides to every question, exactly opposite to each other.

When two friends part they should lock up each other's secrets and exchange keys. The truly noble mind has no resentments.

There is only a finger's difference between a wise man and a fool.

To become self-educated you should condemn yourself for all those things that you would criticize others.

Calumny is only the noise of madmen.

When I look upon seamen, men of science and philosophers, man is the wisest of all beings; when I look upon priests and prophets nothing is as contemptible as man.