Tolstoy is concerned with the idea of a person having a moral center that influences all of their actions. People who do not have a center, such as Pierre, are easily manipulated, whereas someone like Hélène has a corrupted center and can only cause trouble. She is described always by her physical beauty followed by Pierre remarking how she is otherwise rotten. He is learning to judge people. Slowly.
Tolstoy implies Hélène had an incestuous relation with her brother Anatole.