Self-knowledge leads to wonder, and wonder to curiosity and investigation, so that nothing interests people more than people, even if only one’s own person. Every intelligent individual wants to know what makes him tick, and yet is at once fascinated and frustrated by the fact that oneself is the most difficult of all things to know. For the human organism is, apparently, the most complex of all organisms, and while one has the advantage of knowing one’s own organism so intimately—from the inside—there is also the disadvantage of being so close to it that one can never quite get at it. Nothing so eludes conscious inspection as consciousness itself. This is why the root of consciousness has been called, paradoxically, the unconscious.