I have tried to read philosophers of all ages and have found many illuminating ideas but no steady progress toward deeper knowledge and understanding. Science, however, gives me the feeling of steady progress: I am convinced that theoretical physics is actual philosophy. It has revolutionized fundamental concepts, e.g., about space and time (relativity), about causality (quantum theory), and about substance and matter (atomistics), and it has taught us new methods of thinking (complementarity) which are applicable far beyond physics.

It is a fascinating fact that father and son have given the most striking evidence for the apparently contradictory properties of the electron: the father proving its character as a particle, the son its character as a wave... Thomson was extremely proud of his son's success and tried to assimilate the new results into his old convictions.

No language which lends itself to visualizability can describe quantum jumps.

The belief that there is only one truth and that oneself is in possession of it seems to me the deepest root of all evil that is in the world.

Physics as we know it will be over in six months.

The belief in a single truth is the root cause for all evil in the world.

I believe there is no philosophical high-road in science, with epistemological signposts. No, we are in a jungle and find our way by trial and error, building our road behind us as we proceed.