Animals know nothing of themselves, and they also know nothing of the world.

I go in solitude, so as not to drink out of everybody's cistern. When I am among the many I live as the many do, and I do not think I really think; after a time it always seems as if they want to banish myself from myself and rob me of my soul.

Free will without fate is no more conceivable than spirit without matter, good without evil.

Everyone becomes brave when he observes one who despairs.

They would have to sing better songs for me to learn to have faith in their Redeemer; and his disciples would have to look more redeemed!

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.

Where there is the tree of knowledge, there is always Paradise: so say the most ancient and most modern serpents.