"Levin felt guilty but could do nothing.

He felt that if they both spoke without dissimulation and straight from the heart, they would only look into one another's eyes and Constantine would say nothing but, 'You will die! You will die!' and Nicholas would only say in reply: 'I know I shall die and I am afraid, afraid, afraid!' That was all they would say if only they spoke straight from the heart. But that would make life impossible; therefore Constantine tried to do what all his life he had tried and never known how to do (although he had often observed that may people were able to do it well), something without which life was impossible: he tried to say something different from what he thought; and he felt all the time that it sounded false and that his brother detected him and grew irritable." 

- Tolstoy, Anna Karenina, Part III / Chapter XXXII