"In 1931, the Czech-born mathematician Kurt Gödel demonstrated that within any given branch of mathematics, there would always be some propositions that couldn't be proven either true or false using the rules and axioms ... of that mathematical branch itself. You might be able to prove every conceivable statement about numbers within a system by going outside the system in order to come up with new rules and axioms, but by doing so you'll only create a larger system with its own unprovable statements. The implication is that all logical system of any complexity are, by definition, incomplete; each of them contains, at any given time, more true statements than it can possibly prove according to its own defining set of rules."

"You see them? You see them? You see the things that float and flop about you and through you every moment of your life? You see the creatures that form what men call the pure air and the blue sky?
Have I not succeeded in breaking down the barrier; have I not shown you worlds that no other living men have seen?"