Carl Jung tells of a seminal dream in which he was running for his life, at night in a dark forest, pursued by a looming monster he could not seem to escape. The only comfort he had, and the only thing that would light his path as he fled, was the flickering candle he clutched in his hand. All he knew was that he could not slow down, and that he must not let the candle go out. When he awoke, however, it was clear to him that the monster he had been fleeing was the shadow cast by the candle in his hand.