"Hypnotism," asserted Durand de Gros in 1860, "provides psychology with an experimental basis, from which point on it becomes a positive sci ence and takes its place in the larger sphere of animal physiology. " At the time it was written, this pronouncement was perhaps more wish than fact, but it was accurately prophetic of many of the developments in clinical psychiatry in the decades that lay ahead. Charcot was the pioneering pathfinder. With his colleagues at the Salpetriere in Paris, he employed hypnosis as an investigative tool to explore the psychology of patients with major hysteria....