Do you know the story of the scorpion and the frog? You know, the frog agrees to carry the scorpion across the river, because the scorpion promises not to sting him. And then the scorpion stings the frog, half way across the river. The drowning frog asks him why he did it, when they'll both drown, and the scorpion says that he's a scorpion, and it's his nature to sting.
Shantaram (ed. Hachette UK, 2012) - ISBN: 9781405516976