"Blushing is the most peculiar and most human of all expressions."

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

"The more civilized so-called Caucasian races have beaten the Turkish hollow in the struggle for existence."

"I have been much struck by the fact that the more I have read about the subject, the less I have understood it."

"Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult—at least I have found it so—than constantly to bear this conclusion in mind."