I studied so many other things. One question was never adequately answered – by which I mean in general terms, which might be applied to all the camps: what is the optimum physical condition for camp prisoners – that which best corresponds to the demands for productivity and imperatives of security? When prisoners are sick and weak, they don’t work, they are a drain on the assets of the Reich, but when they are healthy, they are dangerous, they think, they rebel, they foment unrest, organise escapes, sabotage equipment, lie to the Kapos who are too stupid to fear what they cannot see, they sap the morale of younger soldiers not yet inured to evil. This problem, which is easy to formulate but difficult to solve, was the subject of countless studies and numerous experiments. There are a number of considerations: firstly, the sick are not always genuinely sick. Research demonstrated that those who claimed to be at death’s door often watched countless co-religionists die before they finally succumbed; and many of those who claimed to be in perfect health were actually suicidal and attempting to kill themselves through work. These are the most dangerous prisoners, desperation makes them cunning, bitter, depraved, they are capable of anything, capable of grabbing a machine gun and firing wildly until they have emptied the last round, of setting fire to the barracks, of rushing a guard and slitting his throat or slamming him against the electric fence until their burning bodies fuse in death. The best advice, often repeated, is to flush them out and eliminate them as a warning to others or – if possible, since they represent the workforce – give them hope. There are many ways of going about this, sometimes a friendly gesture is enough to calm their self-destructive fury, often strong-arm tactics are the only solution.