At one time or another philosophers, scientists, and most other curious people have wondered about the nature of the world out there. Not so much about whether it really exists, for most of us have settled that question, but rather—of what is it really made? The position of a somewhat denigrated group called naïve realists was that the world is truly composed of tables, chairs, red apples, people, etc. Bertrand Russell long ago said that naïve realism slowly led us to physics, which proved naïve realism was wrong. The world of electrons and the stuff of subatomic particles bears no resemblance at all to the red apples that we thought we knew; we are forced to believe in different worlds to fit the occasion or to have two minds—one for subjective experience and one for fundamental objective reality.1 Philosophers have by no means settled on the nature of the world, but only reluctantly have they appreciated the fact that a scientific investigation of what was felt to be a purely epistemological problem was in order.