There is something irreversible about acquiring knowledge; and the simulation of the search for it differs in a most profound way from the reality.

Both the man of science and the man of action live always at the edge of mystery, surrounded by it.

Both the man of science and the man of art live always at the edge of mystery, surrounded by it. Both, as a measure of their creation, have always had to do with the harmonization of what is new with what is familiar, with the balance between novelty and synthesis, with the struggle to make partial order in total chaos.... This cannot be an easy life.

It is not possible to be a scientist unless you believe that it is good to learn... that it is of the highest value to share your knowledge... with anyone who is interested... that the knowledge of the world, and the power which this gives, is a thing which is of intrinsic value to humanity

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'.

Bertrand Russell had given a talk on the then new quantum mechanics, of whose wonders he was most appreciative. He spoke hard and earnestly in the New Lecture Hall. And when he was done, Professor Whitehead, who presided, thanked him for his efforts, and not least for 'leaving the vast darkness of the subject unobscured'.

[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.