What is the author's style in The Drowned and the Saved by Primo Levi?

In this book, Levi attempts to defeat the cynical Nazi certitude that the Holocaust will be seen as a hoax or propaganda because it is too massive to be believed. He writes on behalf of those who do not survive as one who has come close to being drowned but has been saved. He deals with themes that often come up when survivors tell their story, breaking down stereotypes and explaining the rationale of the SS guardians. A sampling of letters from Germans who read Survival in Auschwitz provides valuable perspective.