In all of us, even in good men, there is a lawless wild-beast nature, which peers out in sleep.

Do not go through life like leaf blown from here to there believing whatever you are told.

Do it because it's in your heart. Not because you want something in return. Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for.

A system of morality that is based on relative emotional values is a mere illusion, a thoroughly vulgar conception that has nothing sound in it and nothing true.

No citizen has any right to be an amateur in the matter of physical training; it is part of his profession as a citizen to keep himself in good condition... [It is] a disgrace for a man to grow old without seeing the beauty and the strength of which his body is capable.

True knowledge exists in knowing that you know nothing. And in knowing that you know nothing, that makes you the smartest of all.

No man has a right to be an amateur in the matter of physical training