No one can be perfectly free till all are free; no one can be perfectly moral till all are moral; no one can be perfectly happy till all are happy.

Hero-worship is strongest where there is least regard for human freedom.

Progress, therefore, is not an accident, but a necessity … It is a part of nature.

A clever theft was praiseworthy amongst the Spartans; and it is equally so amongst Christians, provided it be on a sufficiently large scale.

This survival of the fittest which I have here sought to express in mechanical terms, is that which Mr Darwin has called ‘natural selection, or the preservation of favoured races in the struggle for life’.

How often misused words generate misleading thoughts.

Absolute morality is the regulation of conduct in such a way that pain shall not be inflicted.

Evolution … is—a change from an indefinite, incoherent homogeneity, to a definite coherent heterogeneity.

People are beginning to see that the first requisite to success in life is to be a good animal.

Science is organized knowledge.