The right to live does not connote the right of each man to reproduce his kind ... As we lessen the stringency of natural selection, and more and more of the weaklings and the unfit survive, we must increase the standard, mental and physical, of parentage.

The unity of all science consists alone in its method, not in its material.

I look upon statistics as the handmaid of medicine, but on that very account I hold that it befits medicine to treat her handmaid with proper respect, and not to prostitute her services for controversial or personal purposes.

All great scientists have, in a certain sense, been great artists; the man with no imagination may collect facts, but he cannot make great discoveries.

There is no short cut to truth, no way to gain a knowledge of the universe except through the gateway of scientific method.

No matter how much we enjoy following the lives of the rich and famous, we know the world is affected more deeply by quiet, even invisible acts of integrity, kindness, and generosity, than by fame and fortune.

Medals are great encouragement to young men and lead them to feel their work is of value, I remember how keenly I felt this when in the 1890s. I received the Darwin Medal and the Huxley Medal. When one is old, one wants no encouragement and one goes on with one's work to the extent of one's power, because it has become habitual.