Half the useful work in the world consists of combating the harmful work.

The human animal, like others, is adapted to a certain amount of struggle for life [and] the mere absence of effort from his life removes an essential ingredient of happiness. [. . .] He forgets that to be without some of the things you want is an indispensable part of happiness.

Mathematics rightly viewed possesses not only truth but supreme beauty.

I am compelled to fear that science will be used to promote the power of dominant groups rather than to make men happy.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

If we were all given by magic the power to read each other's thoughts, I suppose the first effect would be to dissolve all friendships.

Mathematics takes us into the region of absolute necessity, to which not only the actual word, but every possible word, must conform.