Dissent is the native activity of the scientist, and it has got him into a good deal of trouble in the last years. But if that is cut off, what is left will not be a scientist. And I doubt whether it will be a man.

The hand is the cutting edge of the mind.

I grew up to be indifferent to the distinction between literature and science, which in my teens were simply two languages for experience that I learned together.

Man is unique not because he does science, and his is unique not because he does art, but because science and art equally are expressions of his marvelous plasticity of mind.

All those formal systems, in mathematics and physics and the philosophy of science, which claim to give foundations for certain truth are surely mistaken. I am tempted to say that we do not look for truth, but for knowledge. But I dislike this form of words, for two reasons. First of all, we do look for truth, however we define it, it is what we find that is knowledge. And second, what we fail to find is not truth, but certainty; the nature of truth is exactly the knowledge that we do find.

One original thought is worth the sum total of human knowledge, because it advances the sum total of human knowledge by that one original thought.

It is not the business of science to inherit the earth, but to inherit the moral imagination; because without that, man and beliefs and science will perish together.