In the late 1980s I had a long conversation once with the grandfather a friend of mine in West Berlin. Said grandfather was just an old man with white hair who ate sausages and potatoes at the kitchen table with the family sometimes when I was visiting.

The family didn't like to talk about the old man's prison stint or the fact that he'd once been a moderately high-level bureaucrat in the Nazi government. My friend told me about it one day, though, over beers after his university classes. That sparked my curiosity. I needed to know, or I thought I needed to know, how this very ordinary looking grandfather could have been part of the Nazi machine. I wanted to know how he could have lived with himself.

So one day, alone with him out on the balcony over cold glasses of Berliner Weisse with lemon juice, I asked him.

He was remarkably honest with me, or at least I think he was. He told me that on many levels he knew he was part of something terrible but that he convinced himself a greater good was being served and that he didn't have a choice anyway.

He was promoted to positions of higher responsibilities several times, and by the last promotion, he felt wholly morally compromised. And here's where your article made me think about him again. He told me he only rarely let himself think about how compromised he was, and when he did it was because the thoughts came to him unbidden at night while he tried to sleep.

He pushed them away during the day, he told me, and then he warned me that unless I was an extraordinarily strong person, I would do exactly the same thing under similar circumstances. He told me if I doubted that, I should examine an entire generation of German people who did the same thing he did.

I've never forgotten that conversation because it frightened me terribly.