In Giorgio Agamben's Remnants of Auschwitz: The Witness and the Archive there is a detailed discussion of the Muselmänner (or 'muslim') of the Nazi concentration camps.
Muselmann was the term used by internees in the camps to describe 'the walking dead' of the camps, those who through exposure to starvation, deprivation, violence and brutality experience a fundamental "loss of will and consciousness" (p.45). s Catherine Mills states that Agamben finds in this figure is the limit condition of human life. She says:
"The term 'Muselmann' refers to those in the camps who had reached such a state of physical decrepitude and existential disregard that 'one hesitates to call them living: one hesitates to call their death death' (Levi cited in Agamben: 1999: 44). 'Muselmann' names the 'living corpses' that moved apparently inexorably toward death in the camps, beings who, through exhaustion and circumstance, had lost the capacity for living. They are the 'anonymous mass' that formed 'the backbone of the camps'.."