There are many reports of strange cults which enthral their followers and cut themselves off from the world. Invariably led by gurus, or "spiritual leaders", the fruit of these cults are mass suicides in the South American jungle or the self-immolation of hundreds in besieged fortresses.There are said to be at least six hundred New Religious Movements in Britain, and many more in other parts of the world. They range from benign, charitable organisations to corrupt, dangerous cults which may end in murder or mass suicide. Since cults have a special appeal to the young, anxious parents have prompted a good deal of research into who joins cults and why. Less has been written about the gurus who institute and lead such movements.Gurus are extraordinary individuals who cast doubt upon current psychiatric distinctions between sanity and madness. A guru convinces others that he knows - a persuasive capacity which can bring illumination but which may also and in disaster.Anthony Storr's book is a study of some of the best-known gurus, ranging from monsters such as Jim Jones or David Koresh, to saints such as Ignatius of Loyola. It includes both Freud and Jung because, as Storr demonstrates, what ostensibly began as a scientific investigation became, in each case, a secular path to salvation.'Feet of Clay' is one of Anthony Storr's most original and illuminating books. It demonstrates that most of us harbour irrational beliefs, and discusses how the human wish for certainty in an insecure world leads to confusing delusion with truth. No-one knows, in the sense that gurus claim that they know. Maturity requires us to be able to tolerate doubt. The book ends with reflections upon why human beings need gurus at all, and indicates how those in need of guidance can distinguish the false and dangerous from the genuine and good.