It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition.

What is matter? Never mind.

Thinking you know when in fact you don't is a fatal mistake, to which we are all prone

If one lived for ever the joys of life would inevitably in the end lose their savour. As it is, they remain perennially fresh.

My own belief is that in most ages and in most places obscure psychological forces led men to adopt systems involving quite unnecessary cruelty, and that this is still the case among the most civilized races at the present day.

No other organization rouses anything like the loyalty aroused by the national State. And the chief activity of the State is preparation for large-scale homicide.

Every living thing is a sort of imperialist, seeking to transform as much as possible of its environment into itself.