Look not into the sun! Even the moon is too bright for your nocturnal eyes!

Man is more sensitive to the contempt that others feel towards him than to the contempt that he feels towards himself.

Women are quite able to make friends with a man; but to preserve such a friendship - that no doubt requires the assistance of a slight physical antipathy

Mathematics is merely the means to a general and ultimate knowledge of man.

Along the journey we commonly forget its goal. Almost every vocation is chosen and entered upon as a means to a purpose but is ultimately continued as a final purpose in itself. Forgetting our objectives is the most frequent stupidity in which we indulge ourselves.

Be careful when you fight the monsters, lest you become one.

I know no other way to associate with great tasks than as play: as a sign of greatness, this is an essential presupposition.