Either man will abolish war, or war will abolish man.

Nine-tenths of the appeal of pornography is due to the indecent feelings concerning sex which moralists inculcate in the young; the other tenth is physiological, and will occur in one way or another whatever the state of the law may be.

What is best in mathematics deserves not merely to be learnt as a task, but to assimilated as a part of daily thought, and brought again and again before the mind with ever-renewed encouragement.

I can't tell whether I am living in a dream or a nightmare.

The more you complain the longer God lets you live

There seems scarcely any limit to what could be done in the way of producing a good world, if only men would use science wisely.

The happiness that is genuinely satisfying is accompanied by the fullest exercise of our faculties and the fullest realization of the world in which we live.