Never accept a fact until it has been verified by theory.

Unless the structure of the nucleus has a surprise in store for us, the conclusion seems plain — there is nothing in the whole system of laws of physics that cannot be deduced unambiguously from epistemological considerations.

There was a time when we wanted to be told what an electron is. The question was never answered. No familiar conceptions can be woven around the electron; it belongs to the waiting list.

[When thinking about the new relativity and quantum theories] I have felt a homesickness for the paths of physical science where there are ore or less discernible handrails to keep us from the worst morasses of foolishness.

For the truth of the conclusions of physical science, observation is the supreme Court of Appeal.

Proof is an idol before which the mathematician tortures himself.

Never accept a fact until it has been verified by theory.