The Nazi guards
Levi's exploration of the human experience takes him to the extreme edges of human behavior. He finds that by exploring the relationship between Nazi guards and the Jews they despised in the concentration camps, that interesting psychological phenomena become apparent. He observes the dehumanizing way that the Nazis treated their prisoners, commenting on the decline in mental health and memory abilities among the camp. The effect is undoing and dehumanizing.
The prisoner
The conversation of prison guards and prisoners is specifically applied to the Nazis, so Levi's "prisoner" is a typical Jewish prisoner in the Nazi concentration camp. By examine through evidence and speculation what were the effects of Nazi torture and abuse, Levi shows the inverse opposite psychology of the powerful Nazi guards. The prisoner is broken down emotionally by dehumanizing mistreatment. The clothing and routine of the camps were designed for that effect, so that the "prisoner" becomes a case study for the worst case scenario of human psychology.
