Science may be described as the art of systematic oversimplification.
The point is that, whenever we propose a solution to a problem, we ought to try as hard as we can to overthrow our solution, rather than defend it. Few of us, unfortunately, practice this precept; but other people, fortunately, will supply the criticism for us if we fail to supply it ourselves.
No rational argument will have a rational effect on a man who does not want to adopt a rational attitude.
True ignorance is not the absence of knowledge, but the refusal to acquire it.
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.