The doctrine that all men are, in any sense, or have been, at any time, free and equal, is an utterly baseless fiction.

The birth of science was the death of superstition.

The method of scientific investigation is nothing but the expression of the necessary mode of working of the human mind.

If the twentieth century is to be better than the nineteenth, it will be because there are among us men who walk in Priestley's footsteps....To all eternity, the sum of truth and right will have been increased by their means; to all eternity, falsehoods and injustice will be the weaker because they have lived.

I have never been able to understand why pigeon-shooting at Hurlingham should be refined and polite, while a rat-killing match in Whitechapel is low.

Do what you can to do what you ought, and leave hoping and fearing alone.

It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organization upon the natural organization of the body.