Mathematics takes us into the region of absolute necessity, to which not only the actual word, but every possible word, must conform.

I can only say that, while my own opinions as to ethics do not satisfy me, other people's satisfy me still less.

It is for this reason that rationality is of supreme importance to the well-being of the human species...even more, in those less fortunate times in which it is despised and rejected as the vain dream of men who lack the virility to kill where they cannot agree.

Language serves not only to express thought but to make possible thoughts which could not exist without it.

Human nature is so constructed that it gives affection most readily to those who seem least to demand it.

The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself.

The reason is, and by rights ought to be, slave to the emotions.