God is a scientist, not a magician.

The more a man is imbued with the ordered regularity of all events the firmer becomes his conviction that there is no room left by the side of this ordered regularity for causes of a different nature. For him neither the rule of human nor the rule of divine will exist as an independent cause of natural events.

At present every coachman and every waiter argues about whether or not the relativity theory is correct.

Common sense is the collection of prejudices acquired by age eighteen.

It is open to every man to choose the direction of his striving; and also every man may draw comfort from Lessing's fine saying, that the search for truth is more precious than its possession.

Most mistakes in philosophy and logic occur because the human mind is apt to take the symbol for the reality.

Great spirits have always encountered opposition from mediocre minds. The mediocre mind is incapable of understanding the man who refuses to bow blindly to conventional prejudices and chooses instead to express his opinions courageously and honestly.