In our current era of holy terror, passionate faith has come to seem like a present danger. Writers such as Richard Dawkins, Sam Harris, and Christopher Hitchens have been happy to throw the baby out with the bathwater and declare that the danger is in religion itself. God, Hitchens writes, is not great. But man, according to George E. Vaillant, M.D, is great. In Spiritual Evolution, Dr. Vaillant lays out a brilliant defense not of organized religion but of man's inherent spirituality. Our spiri