Communism was not the crazy fantasy of a few fanatics, nor the result of human stupidity and baseness; it was a real, very real part of the history of the twentieth century, and we cannot understand this history of ours without understanding communism. We cannot get rid of this specter by saying it was just "human stupidity,” or "human corruptibility.” The specter is stronger than the spells we cast on it. It might come back to life.