“The possible relevance of these experiments to sudden religious and political conversion should be obvious even to the most skeptical: Pavlov has shown by repeated and repeatable experiment just how a dog, like a man, can be conditioned to hate what it previously loved, and love what it previously hated. Similarly, one set of behavior patterns in man can be temporarily replaced by another that altogether contradicts it; not by persuasive indoctrination alone, but also by imposing intolerable strains on a normally functioning brain”