Now he is 93 years old and on trial in Lüneberg Germany as an accessory to murder. Whether he will be found guilty remains to be seen, but he has not hesitated to declare his moral guilt.
"For me, there's no question that I share moral guilt", he said. "I ask for forgiveness."
But his declaration invites the question: what did he do wrong?
Groening was no monster. He was morally sickened by what was going on around him. He was not an unthinking bureaucrat – the description Hannah Arendt gave to Adolph Eichmann. He was not in a position of authority. He was not trying to evade the dangers of war. He applied for a transfer even though he knew he would be sent to a combat zone.
Peter Singer in his recent book, The Most Good You Can Do (2015), writes that a morally conscientious guard at Auschwitz is doing nothing wrong by staying at his post. If he leaves, someone else – possibly worse – will be put in his place. To protest is fruitless and will only get him killed.
Singer takes this position because he believes that whether an act is morally bad or good depends entirely on its consequences. If nothing else you can do will make things better for anyone then you can't be blamed for wrongdoing.
According to this reasoning Groening is not morally guilty.
But Singer's moral philosophy differs from the views of most people about right and wrong. Most of us think that people are morally good if they act in obedience to moral rules – if they do not kill, cheat, betray or lie.
But Groening did not kill anyone. He was an honest accountant. So far as we know he did not betray anyone. Perhaps he can be blamed for joining the SS. People have a duty to avoid being led astray by false doctrines. But this fault has nothing directly to do with his activities at Auschwitz.
The German philosopher Karl Jaspers addressed German guilt for the crimes of the Nazis, by identifying four concepts of guilt.
People can be guilty in a legal sense and politically guilty as citizens of an unjust state. Individuals are morally guilty for the particular wrongs that they committed. But people also bear what he calls "metaphysical guilt". In his book The Question of German Guilt, published in 1947, he wrote:
If I was present at the murder of others without risking my life to prevent it, I feel guilty in a way not adequately conceivable either legally, politically or morally.
Jaspers does not say that people like Groening had a moral duty to sacrifice their lives in order to stand up for the right. But he is pointing to a common source of guilty feelings: the taint of wrongdoing that infects people who witness terrible evils or are associated with wrongdoers.
But by asking for forgiveness, Groening makes it clear that he does not regard himself as guilty simply because he was in a place where terrible wrongs were committed. He regards himself as guilty for what he did.
If Groening is guilty of anything he is guilty of complicity: of participating in the commission of a wrong. Complicity, as we usually understand it, requires participants to share an intention to do wrong. Members of a criminal gang are complicit in a murder if they act together with the intention to kill.
But Groening did not share the intention of killing Jews. He strongly disagreed with that objective. To find him guilty of complicity we have to accept that a person who works for an organisation that commits wrong can be complicit even if he morally objects to what it is doing and even if he doesn't want to participate.
If you think that Groening is guilty then you should also agree that if you work for a company or bureaucracy that is committing injustices, then you are guilty of wrongdoing even if your own work makes no direct contribution to the wrong, and even if you do not approve of its unjust actions.
If you have no choice about where you work, or if you don't know that your organisation is doing wrong, then maybe you have an excuse. Otherwise you share the guilt.
The concept of guilt that we need in order to condemn Oskar Groening is more stringent than the one we usually use in assessing our own actions and the actions of our friends. But there are good reasons for adopting it.
The crimes committed at Auschwitz were committed collectively. Auschwitz couldn't have operated without the cooperation of those who worked there. Accountants as well as those directly involved in killing were necessary for its smooth operation. Without a conception of collective guilt that embraces all of those who contributed, it is impossible to account for the wrong done.
So let's agree that Oskar Groening is morally guilty. But let us also consider the implications for our own participation in collective activities.
This article was originally published in The Conversation.
Janna Thompson is a Professor of Philosophy.
Image: EPA/Axel Heimken/Pool