For those who have seen the movie, The Reader, what do you make of Kate Winslet's character (warning, spoilers)?

First off let me say that it was an extraordinary performance that made the character seem credible. But I wonder if there are such people. She seems to be completely non-reflective, an example of the unexamined life that Socrates warned against. Do you think such people exist, that she could participate in killings and simply not have anything register? And how can she be that way and also have such an appreciation of literature?