Non-cooperation in military matters should be an essential moral principle for all true scientists.

The value of achievement lies in the achieving.

Never do anything against conscience even if the state demands it.

Long live impudence. It was my guardian angel in this world.

The wonder of nature does not become smaller because one cannot measure it by the standards of human moral and human aims.

But there is another reason for the high repute of mathematics: it is mathematics that offers the exact natural sciences a certain measure of security which, without mathematics, they could not attain.

It's no accident that capitalism has brought with it progress, not merely in production but also in knowledge. Egoism and competition are, alas, stronger forces than public spirit and sense of duty.