What are the motifs in Survival in Auschwitz by Primo Levi?

One of the reoccurring ideas of the autobiography is that of the social upheaval and vile practices of the Nazi Third Reich. Levi refers to this as the collective great insanity of the third Germany. Levi chronicles this paradigm—he bears witness—but he does not analyze it or attempt to explain it, instead concluding that for him, it is inexplicable.