Science does not aim at establishing immutable truths and eternal dogmas; its aim is to approach the truth by successive approximations, without clai… - Bertrand Russell

A physicist looks for causes; that does not necessarily imply that there are causes everywhere. A man may look for gold without assuming that there is gold everywhere; if he finds gold, well and good, if he doesn't he's had bad luck. The same is true when the physicists look for causes.

One of the symptoms of approaching nervous breakdown is the belief that one's work is terribly important, and that to take a holiday would bring all kinds of disaster. If I were a medical man, I should prescribe a holiday to any patient who considered his work important.

A drop of water is not immortal; it can be resolved into oxygen and hydrogen. If, therefore, a drop of water were to maintain that it had a quality of aqueousness which would survive its dissolution we should be inclined to be skeptical. In like manner we know that the brain is not immortal...