To live remains an art which everyone must learn, and which no one can teach.

Even the most scientific investigator in science, the most thoroughgoing Positivist, cannot dispense with fiction; he must at least make use of categories, and they are already fictions, analogical fictions, or labels, which give us the same pleasure as children receive when they are told the "name" of a thing.

Every artist writes his own autobiography.

Birth-control is effecting, and promising to effect, many functions in our social life.

We cannot be sure that we ought not to regard the most criminal country as that which in some aspects possesses the highest civilization.

The conflict of forces and the struggle of opposing wills are of the essence of our universe and alone hold it together.

The greatest task before civilization at present is to make machines what they ought to be, the slaves, instead of the masters of men.