My own view on religion is . . . It helped in early days to fix the calendar, and . . . to chronicle eclipses . . . These two services I am prepared to acknowledge.

The main thing needed to make men happy is intelligence.

Love should be a tree whose roots are deep in the earth, but whose branches extend into heaven.

Orthodoxy is the death of intelligence.

It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly.

The essence of education is that it is a change effected in the organism to satisfy the operator.

Man is the product of causes which had no prevision of the end they were achieving; his origin, his growth, his hopes and fears, his loves and beliefs, are but the outcome of accidental collocations of atoms; no fire, no heroism, no intensity of though and feeling, can preserve an individual life beyond the grave.