Man selects only for his own good: Nature only for that of the being which she tends.

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

From the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of higher animals, directly follows.

With highly civilised nations continued progress depends in a subordinate degree on natural selection; for such nations do not supplant and exterminate one another as do savage tribes.

Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy.

I have steadily endeavored to keep my mind free so as to give up any hypothesis, however much beloved (and I cannot resist forming one on every subject), as soon as the facts are shown to be opposed to it.

We are not here concerned with hopes or fears, only with truth as far as our reason permits us to discover it.