Man, biologically considered ... is simply the most formidable of all beasts of prey, and, indeed, the only one that preys systematically on its own kind.

My experience is what I agree to attend to.

Our ideas must agree with realities, be such realities concrete or abstract

The great thing, then, in all education, is to make our nervous system our ally instead of our enemy.

The lunatic's visions of horror are all drawn from the material of daily fact. Our civilization is founded on the shambles, and every individual existence goes out in a lonely spasm of helpless agony.

He who refuses to embrace a unique opportunity loses the prize as surely as if he had failed.

History is a bath of blood.