Heresy arises when the right thing to do is to do something that is wrong. It is insisting that two plus two equals four when the proper, patriotic, and professional thing to do is to say that it equals five. It is believing that the earth revolves around the sun when Luther, Calvin, and Cardinal Bellarmine tell us that the sun revolves around the earth. Of course, it would be a mistake to think that heresy is always right. It is not. Moreover, heresy often has nothing to do with right or wrong, in the literal—mathematical or scientific—sense of these terms. However, it does have to do with not believing what others believe or what oneself should believe, or with proclaiming that one does not believe when the right thing to do would be to profess that belief or, at least, to remain silent. Heresies is an entirely personal book by Thomas Szasz, one of the most eminent psychiatrists and philosophers of contemporary psychiatry, composed of a series of observations and reflections on various topics, but which revolve mainly around language, the normal and the abnormal within the social order, medicine, sexuality, morality, madness and the most definitive themes of what has been called anti-psychiatry.