"The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know; our knowledge of our ignorance. For this indeed, is the main source of our ignorance - the fact that our knowledge can be only finite, while our ignorance must necessarily be infinite."
"While differing widely in the various little bits we know, in our infinite ignorance we are all equal."
"Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve."
"Science may be described as the art of systematic oversimplification."
"No rational argument will have a rational effect on a man who does not want to adopt a rational attitude."
"No book can ever be finished. While working on it we learn just enough to find it immature the moment we turn away from it"