Bolkonsky Goes a Little Bazarov

"“The one thing for which I thank God is that I didn't kill that man,” said Pierre. 

“Why so?” said Prince Andrey. “To kill a vicious dog is a very good thing to do, really.” 

“No, to kill a man is bad, wrong …” 

“Why is it wrong?” repeated Prince Andrey; “what's right and wrong is a question it has not been given to men to decide. Men are for ever in error, and always will be in error, and in nothing more than in what they regard as right and wrong.” “

What does harm to another man is wrong,” said Pierre, feeling with pleasure that for the first time since his arrival Prince Andrey was roused and was beginning to speak and eager to give expression to what had made him what he now was. 

“And who has told you what is harm to another man?” he asked. 

“Harm? harm?” said Pierre; “we all know what harms ourselves.” 

“Yes, we know that, but it's not the same harm we know about for ourselves that we do to another man,” said Prince Andrey, growing more and more eager, and evidently anxious to express to Pierre his new view of things. He spoke in French. “I only know two very real ills in life, remorse and sickness. There is no good except the absence of those ills. To live for myself so as to avoid these two evils: that's the sum of my wisdom now.”"

Tolstoy, Leo. War and Peace. Translated by Constance Garnett. Amazon Digital Services, Inc., August 24, 2015.