A young man from an aristocratic but poor family, Boris is a no-holds-barred striver and social climber whose only motive is getting ahead.
Boris might be one the most striking examples in the book of the narrator's impartiality. Imagine how this ultimate grade grubber would be portrayed in most novels. Would the narrator just kind of describe his actions with no judgment? No way. Maybe Boris wouldn't be the biggest bad guy ever, but he would certainly be a cautionary tale of the evils of not being happy with your station in life. Boris would most likely come to some terrible end – probably a fitting one tied to his love of money and rank.
But in War and Peace, no such thing happens. Boris gets to have his cake and eat it too. He rises higher and higher through the army ranks without a problem. He marries ugly, annoying Julie Karagin for her money and seems none the worse for the transaction. We can think whatever ill of him we want, but the novel isn't going to do our dirty work for us.