Light may be shed on man and his origins.

I have called this principle, by which each slight variation, if useful, is preserved, by the term natural selection.

The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain agnostic.

As for a future life, every man must judge for himself between conflicting vague possibilities.

A man who dares to waste one hour of life has not discovered the value of life.