One should as a rule respect public opinion in so far as is necessary to avoid starvation and to keep out of prison, but anything that goes beyond this is voluntary submission to an unnecessary tyranny.

Civilized life has altogether grown too tame, and, if it is to be stable, it must provide a harmless outlets for the impulses which our remote ancestors satisfied in hunting.

Too little liberty brings stagnation, and too much brings chaos.

Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.

One must expect a war between U.S.A. and U.S.S.R. which will begin with the total destruction of London. I think the war will last 30 years, and leave a world without civilised people, from which everything will have to build afresh - a process taking (say) 500 years.

It is possible that mankind is on the threshold of a golden age; but, if so, it will be necessary first to slay the dragon that guards the door, and this dragon is religion.

One of the most painful circumstances of recent advances in science is that each one makes us know less than we thought we did