When we are talking about a system of state-sanctioned collective violence, the question of “how was it possible?” goes to the heart of what might be called an anatomy of evil and guilt. A significant strand of perpetrator research on the Third Reich has focused on individual personalities, the role of ideology, and personal motives; but others have pointed to the importance of situational factors, including processes of brutalization and peer group pressure. In the first part of this paper I discuss the significance of inner distancing as a psychological concomitant of living within an intrusive regime; and I explore the ways in which people were mobilized to perform specific roles, as cogs in the machine, without feeling personally responsible for the consequences of their actions — however close to or distant from the ultimately murderous outcomes they might be. The second part of the paper turns to questions around guilt, both in the legal sense of who was held to be culpable, and in the experiential sense of who felt guilty. I reconsider questions of perpetratorhood in terms of different legal systems, and in terms of the differing ways in which people sought retrospectively to narrate and justify their acts in order to live with an uncomfortable past. By proposing an analytical schema for understanding anatomies of evil and guilt, here primarily developed with reference to the Holocaust, I try to recombine psychological and historical analyses in ways that do justice to at least some of the complexities.