If I had life to live over again, I would give my life to poetry, to music, to literature, and to art to make life richer and happier. In my youth I steeled myself against them and thought them so much waste.

...one doubts existence of free will [because] every action determined by heredity, constitution, example of others or teaching of others." "This view should teach one profound humility, one deserves no credit for anything...nor ought one to blame others.

It is always advisable to perceive clearly our ignorance.

In the struggle for survival, the fittest win out at the expense of their rivals because they succeed in adapting themselves best to their environment.

Free will is to mind what chance is to matter.

If man had not been his own classifier, he would never have thought of founding a separate order for his own reception.

If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.