"But I am very poorly today & very stupid & I hate everybody & everything. One lives only to make blunders."

"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."

"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…"

"An American monkey, after getting drunk on brandy, would never touch it again, and thus is much wiser than most men."

"It is a cursed evil to any man to become so absorbed in any one subject as I am in mine."