“Man in his arrogance thinks himself a great work worthy the interposition of a deity. More humble, and I believe truer, to consider him created from animals.”

“I love fools' experiments. I am always making them.”

“How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!”

“What a book a Devil's chaplain might write on the clumsy, wasteful, blundering, low, and horridly cruel works of nature!”

“Though the theory is worthless without the well-observed facts, the facts are useless without the frame of the theory to receive them.”

“As far as I can judge, I am not apt to follow blindly the lead of other men. I have steadily endeavoured 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 facts are shown to be opposed to it.”

“It all comes to this: the simplest way to be happy is to do good.”

“Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or nothing.”

“There never has been security. No man has ever known what he would meet around the next corner; if life were predictable it would cease to be life, and be without flavor.”

“One of the blessings of age is to learn not to part on a note of sharpness, to treasure the moments spent with those we love, and to make them whenever possible good to remember, for time is short.”

“Happiness is not a goal, it is a by-product. Paradoxically, the one sure way not to be happy is deliberately to map out a way of life in which one would please oneself completely and exclusively.”

“The purpose of life is to live it, to taste experience to the utmost, to reach out eagerly and without fear for newer and richer experience.”