The book isn't so much an account of events that took place during the Holocaust, but of the individual, subjective experiences of those who were sent to concentration camps, what they had to endure, what happened to their minds and bodies, and the life-or-death dilemmas they had to confront on a daily basis. This is an account written by a particularly thoughtful, honest and courageous psychologist who was able to interpret such experiences in light of larger issues about humanity in general.
The following is just one chilling example of the kind of insight and epiphany that makes this book one everyone ought to read:
On the average, only those prisoners could keep alive who, after years of trekking from camp to camp, had lost all scruples in their fight for existence; they were prepared to use every means, honest and otherwise, even brutal force, theft, and betrayal of their friends, in order to save themselves. We who have come back, by the aid of many lucky chances or miracles—whatever one may choose to call them—we know: the best of us did not return.
That quote just sends cold chills down my spine...