Science and literature are not two things, but two sides of one thing.

Of all the senseless babble I have ever had occasion to read, the demonstrations of these philosophers who undertake to tell us all about the nature of God would be the worst, if they were not surpassed by the still greater absurdities of the philosophers who try to prove that there is no God.

My fundamental axiom of speculative philosophy is that materialism and spiritualism are opposite poles of the same absurdity-the absurdity of imagining that we know anything about either spirit or matter.

I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young.

Matter and force are the two names of the one artist who fashions the living as well as the lifeless.

It is the first duty of a hypothesis to be intelligible.

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.