Pragmatism is an intellectually safe but ultimately sterile philosophy.

'It worked.' (said after witnessing the first atomic detonation).

When you see something that is technically sweet you go ahead and do it.

I remembered the line from the Hindu scripture, the Bhagavad-Gita... "Now I am become Death, the destroyer of worlds." I suppose we all thought that, one way or another.

If we ask, for instance, whether the position of the electron remains the same, we must say 'no'; if we ask whether the electron's position changes with time, we must say 'no'; if we ask whether the electron is at rest, we must say 'no'; if we ask whether it is in motion, we must say 'no'.

[About the great synthesis of atomic physics in the 1920s:] It was a heroic time. It was not the doing of any one man; it involved the collaboration of scores of scientists from many different lands. But from the first to last the deeply creative, subtle and critical spirit of Niels Bohr guided, restrained, deepened and finally transmuted the enterprise.

It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them.