Forgiveness
The book is about forgiveness and for this reason it is also the central theme of both the story about Karl, and the responses from religious leaders and scholars. Karl asks Simon to forgive his crimes, but Simon refuses. He is, however, compassionate in doing so, and is also plagued by guilt himself because he does not know if he did the right thing or not.
One of the questions the book asks constantly is whether compassion can take the place of forgiveness when forgiveness cannot be offered. All of the respondents to Simon's questions agree that, regardless of their opinion about whether or not he should have forgiven Karl, he acted with tremendous compassion towards him. Simon is not being vengeful in his turning down Karl's request; he believes that forgiveness is not his to give and that he cannot forgive a crime that was against other people.
Simon is also unwilling to forgive those who were complicit in the Nazis crimes even if they themselves did not support them. When he visits Karl's mother, he is again kind, compassionate and displays his humanity by sparing her the details of her son's actions; however, he reminds her that all Germans bear a responsibility for the Holocaust whether they were active or silent participants.
Silence and Complicity
"All it takes for evil to flourish is for good men to do nothing."
Simon believes that the silence of "ordinary" Germans during Hitler's regime was a form of complicity with their actions. He feels that their silence in the face of the murderous injustices going on around them makes them just as culpable as the Nazi perpetrators. Simon and other prisoners were taken outside camp walls on many occasions and were seen by many Germans outside, yet not one did anything, viewing them as sort of a lost cause, people who were doomed anyway so that they could absolve themselves of the responsibility of actually doing something. People deluded themselves that they were powerless to do anything so that they would not even have to attempt it. The silence and denial of so many even when atrocity is obvious can make a whole society responsible for allowing this kind of evil to flourish.
Anti-Semitism
One of the book's main themes is anti-Semitism and there are many ways in which Simon describes his experiences of this. He recalls, for instance, that whilst he was a student at the technical college, students held a No Jews day when they brutalized Jewish students with no punishment to themselves afterwards.
He describes the ghettoes that the Jews were forced to live in before they were taken to the gas chambers and death camps. He also explains that many ordinary citizens in Germany, Austria and Poland were suspicious of their Jewish neighbors and that they allowed them to be sacrificed so that the Nazis would not come for them instead. Karl demonstrates his own, unconscious anti-Semitism by believing that forgiveness from a random Jew is the same thing as forgiveness from the Jewish family he murdered, as if he sees all Jews as one and the same.
Nazi War Crimes
The book describes in detail the daily dehumanization of those imprisoned in death camps. The prisoners were Jewish, Polish, those who ran the Resistance - anyone whom the Nazis believed was a threat to them and their plans. The camps were brutal; daily beatings, starvation, unimaginable atrocities designed to systematically take away each prisoner's humanity. When the prisoners were taken outside camp to the villages surrounding it, Simon describes the way in which the villagers looked at them, as if they were cattle being led to slaughter rather than men.
The story of Eli also demonstrates the sheer scope of the evil that the Nazis perpetrated. A fake kindergarten was created so that parents would send their children to school, and as soon as they did, the children were taken away to the gas chambers. Karl's own story of locking three hundred Jewish people in a building and setting fire to it also shows that the Nazis did not view them as human.
Remembrance
The subject of remembrance is first raised by Simon; when he goes by a cemetery for German soldiers he is touched by the sunflower placed atop each of their graves; he is also envious, because he fears he will never receive this kind of remembrance but that instead he will end up in a mass grave with thousands of other prisoners.
Most of those who agree that Simon was right not to offer Karl forgiveness also do so because they fear that forgiveness leads to a steady decline in remembrance, and that if these acts are forgiven then they will eventually become forgotten. This can never be allowed to happen. Those who believe he should forgive do not advocate forgetting yet it is fear of these two things going hand in hand that Simon fears as time passes.
