It is in literature that the concrete outlook of humanity receives its expression.

People make the mistake of talking about 'natural laws.' There are no natural laws. There are only temporary habits of nature.

The absolute pacifist is a bad citizen; times come when force must be used to uphold right, justice and ideals.

Algebra reverses the relative importance of the factors in ordinary language.

To see what is general in what is particular, and what is permanent in what is transitory, is the aim of scientific thought.

A race preserves its vigor so long as it harbors a real contrast between what has been and what may be; and so long as it is nerved by the vigor to adventure beyond the safeties of the past. Without adventure civilization is in full decay.

There is no greater hindrance to the progress of thought than an attitude of irritated party-spirit.