"To kill an error is as good a service as to establish a new truth."

"If a man were to read a book on the cultivation of fruit trees, and then attempt to practice it without having seen a single tree, he would not be more unsuccessful than those who attempt to philosoph…"

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

"My mind seems to have become a kind of machine for grinding general laws out of large collections of facts."

"He who understands baboon would do more towards metaphysics than Locke."