This is a most unpleasant book. It is important for recognizing the potential evil existing in humanity (ourselves – that means YOU and ME). I confess I only read the book because Jordan Peterson recommended it.
It documents how ordinary men, most of whom under normal conditions, would never dream of performing horrific acts of murder of helpless old men and women, children, men, women and even pregnant women! Under conditions of war and receiving orders, they nevertheless performed them!
The first few chapters just plainly describes with historical proof the mass killing of Jews by mostly middle aged policemen recruited to avoid depleting the ranks of more fit younger men to fight in WW2. There was a great aversion to doing this by most, and a few refused, but not out of morality per se, but out of disgust. Others performed them only out of fear of being called a coward or weak or betraying your country. Actually forcing these men to kill was almost never the case, which greatly surprised me. They were directed and ordered to do it, and most did. Those who refused were often shunned by the others, but rarely punished.
Later the book goes into more detail about anti-Semitism in Germany and the NAZI dehumanizing of the Jews. Rationalization by these “ordinary men” was that Jews are the enemy and this is a job someone has to do, and after all they are or would be bombing German civilians if and when they do.
Like reading the Gulag Archipelago, I would not listen to it all at once, but maybe a chapter once a week or a month, so you don’t get too depressed! Oh, the reader is very good and unemotionally reads, making it all the more shocking and poignant!