The military superiority of Europe to Asia is not an eternal law of nature, as we are tempted to think, and our superiority in civilization is a mere delusion.

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.

Clergymen almost necessarily fail in two ways as teachers of morals. They condemn acts which do no harm and they condone acts which do great harm.

Science, in its ultimate ideal, consists of a set of propositions arranged in a hierarchy, the lowest level of the hierarchy being concerned with particular facts, and the highest with some general law, governing everything in the universe. The various levels in the hierarchy have a two-fold logical connection, travelling one up, one down; the upward connection proceeds by induction, the downward by deduction.

The secrets to happiness include enterprise, exploration of one's interests and the overcoming of obstacles.

If a Black Death could be spread throughout the world once in every generation survivors could procreate freely without making the world too full.

I've made an odd discovery. Every time I talk to a savant I feel quite sure that happiness is no longer a possibility. Yet when I talk with my gardener, I'm convinced of the opposite.