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

"The fact that I can't remember anything from the first three years of my life is no proof that I wasn't an embryo then."

"The very existence of our senses, our reason, and our intellect, is a proof that these faculties were given us for some purpose."

"I have tried lately to read Shakespeare, and found it so intolerably dull that it nauseated me."

"I am almost convinced that species are not (it is like confessing a murder) immutable."