I have come to the conclusion that my subjective account of my motivation is largely mythical on almost all occasions. I don't know why I do things.

The conservative has but little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of the passions. These are the wreckers of outworn empires and civilisations, doubters, disintegrators, deicides.

Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins.

A fairly bright boy is far more intelligent and far better company than the average adult.

Teleology is like a mistress to a biologist: he cannot live without her but he's unwilling to be seen with her in public.

It was a reaction from the old idea of "protoplasm", a name which was a mere repository of ignorance.

Science is as yet in its infancy, and we can foretell little of the future save that the thing that has not been is the thing that shall be; that no beliefs, no values, no institutions are safe.