It is wrong to think that belief in freedom always leads to victory; we must always be prepared for it to lead to defeat. If we choose freedom, then we must be prepared to perish along with it.
He who decides one day that scientific statements do not call for any further test and that they can be regarded as finally verified retires from the game.
The method of learning by trial and error – of learning from our mistakes – seems to be fundamentally the same whether it is practiced by lower or by higher animals, by chimpanzees, or by men of science.
