The perfect woman is a higher type of humanity than the perfect man, and also something much rarer. The natural history of animals furnishes grounds in support of this theory.

Mathematics would certainly have not come into existence if one had known from the beginning that there was in nature no exactly straight line, no actual circle, no absolute magnitude.

One cannot read the New Testament without acquired admiration for whatever it abuses not to speak of the "wisdom of this world," which an impudent wind bag tries to dispose of "by the foolishness of preaching."

What is life? A continuous praise and blame.

Religious War has signified the greatest advance of the masses so far, for it proves that the masses have begun to treat concepts with respect.

When our brain feels too weak to deal with our opponent's objections, our heart answers by casting suspicion on their underlying motives.

Nobody can build the bridge for you to walk across the river of life, no one but you yourself alone. There are, to be sure, countless paths and bridges and demi-gods which would carry you across this river; but only at the cost of yourself; you would pawn yourself and lose. There is in the world only one way, on which nobody can go, except you: where does it lead? Do not ask, go along with it.