[Scientists] have learned to respect nothing but evidence, and to believe that their highest duty lies in submitting to it however it may jar against their inclinations.

The only question which any wise man can ask himself, and which any honest man will ask himself, is whether a doctrine is true or false.

Though under-instruction is a bad thing, it is not impossible that over-instruction may be worse.

Can any one deny that the old Israelites conceived Jahveh not only in the image of a man, but in that of a changeable, irritable, and, occasionally, violent man?

I'd rather have an ape for an ancestor than a bishop.

The thief and the murderer follow nature just as much as the philanthropist.

Deduction, which takes us from the general proposition to facts again-teaches us, if I may so say, to anticipate from the ticket what is inside the bundle.