Marianne Paget's "The Unity of Mistakes" has long been considered a landmark text on the nature of medical error. Paget who herself died because of a medical error argued that mistakes are an intrinsic part of the clinical process. Encompassing a much wider range of error than the terms 'malpractice', 'incompetence', or 'negligence' denote, "The Unity of Mistakes" takes an existential view of medical work in which things go wrong as a matter of course, and probes what Paget called the 'complex sorrow' that can result when things do go wrong. This new paperback edition contains a Foreword by Joan Cassell, anthropologist and author of "Expected Miracles: Surgeons at Work". 'I began this study when I became aware of the anguish of clinical action and of the moral ambiguity of being a clinician, a person who acts, acts sometimes mistakenly, and, therefore, lives with the experience of being wrong'.With this statement, Marianne Paget introduces her study of medical mistakes and their meaning. Using as her 'text' in-depth interviews with forty doctors, she explores the subjective experience of physicians who inevitably make mistakes. Marianne Paget argues that mistakes are an intrinsic feature of medical work which she calls an error-ridden activity. Mistakes involve action and action contains risk. Since medical mistakes put at risk human beings (not just the acted upon but the actors), her concern is with the subtle effects this endemic danger has upon clinical work. Through close textual analysis, the author examines the ways in which particular actions (which seemed right at the time) are recognized as errors and responded to. Her study encompasses a much wider range of error than the terms 'malpractice', 'incompetence', or 'negligence' denote.She takes an existential view of medical work in which things go wrong as a matter of course and probes what she calls the 'complex sorrow' that can result. Author note: Marianne A. Paget (1940-1989) was a sociologist and researcher who in the course of her career held positions at various universities, and at the time of her death was a research associate in the Department of Sociology at Brandeis University. Joan Cassell is Research Associate in the department of Anthropology at Washington University in St. Louis, and the author of several books, including "Expected Miracles: Surgeons at Work" and "The Surgeon in the Woman's Body".