It is impossible to get anywhere without sinning against reason.

The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have not legitimacy.

Everybody felt his superiority, but nobody felt oppressed by it. Though he had no illusions about people and human affairs, he was full of kindness toward everybody and everything. Never did he give the impression of domineering, always of serving and helping. He was extremely conscientious, without allowing anything to assume undue importance; a subtle humor guarded him, which was reflected in his eyes and in his smile.

Knowledge is limited.

Common sense is nothing more than a deposit of prejudices laid down by the mind before you reach eighteen.

I believe in Spinoza's God, who reveals Himself in the lawful harmony of the world, not in a God who concerns Himself with the fate and the doings of mankind... to Rabbi Herbert Goldstein (1929)

Nationalism is the measels of mankind.