During the 1940s and 1950s, tens of thousands of Americans underwent some form of psychosurgery; that is, their brains were operated upon for the putative purpose of treating mental illness. From today's perspective, such medical practices appear foolhardy at best, perhaps even barbaric; most commentators thus have seen in the story of lobotomy an important warning about the kinds of hazards that society will face whenever incompetent or malicious physicians are allowed to overstep the boundaries of valid medical science. Last Resort challenges the previously accepted psychosurgery story and raises new questions about what we should consider to be its important lessons. Through an extensive study of patient records, professional correspondence, and the day's medical literature, Jack D. Pressman establishes that lobotomy occurred, not at the periphery of medical practice, but at its center - a finding that engenders a different set of historical problems. To account for why so many reasonable and trusted physicians might have supported psychosurgery's validity, the book reconstructs the particular challenges facing the psychiatrists of the time and the kinds of disciplinary tools that were available to them. The new lesson that emerges from the psychosurgery story, then, is that our usual models of understanding how medicine progresses are deeply flawed. The success of a research venture in medicine is never a safe bet, and the evaluation of therapeutic success is not an absolute measure, being relative to time and place. The standard of what constitutes valid medical science is itself never fixed, but evolving.