When the mind grapples with a great and intricate problem, it makes its advances step by step, with but little realization of the gains it has made, until suddenly, with an effect of abrupt illumination, it realizes its victory.

The brain upon which my experiences have been written is not a particularly good one. If their were brain-shows, as there are cat and dog shows, I doubt if it would get even a third class prize.

Every time Europe looks across the Atlantic to see the American Eagle, it observes only the rear end of an ostrich.

The study of Nature makes a man at last as remorseless as Nature.

The character of the Open Conspiracy [the movement towards a world collective] will now be plainly displayed. It will have become a great world movement as widespread and evident as socialism or communism. It will largely have taken the place of these movements. It will be more, it will be a world religion.

States organized for war will make war as surely as hens will lay eggs.

I never yet heard of a useless thing that was not ground out of existence by evolution sooner or later. Did you? And pain gets needless.