Between 1939 and 1945 the Nazis systematically murdered as many as 200,000 mentally ill or physically disabled people whom they stigmatised as 'life unworthy of life'. This complex and covert series of operations was known as the 'euthanasia' programme. It provided many of the personnel and the technical expertise later deployed in the 'Final Solution'. This is the first full-scale study in English of the 'euthanasia' programme. It considers the role of all those involved in these policies: bureaucrats, doctors, nurses, health officials, lawyers, clerics, and also parents, relatives, and the patients themselves. Using a wealth of original archival material, it highlights many of the moral issues involved in a way that is profoundly disquieting. The book concludes by showing the ease with which many of the perpetrators filtered back into German society after 1945.