The essayist doesn't but Vimes world character arc requires that he see the issue in black and white, top and bottom.
I'm sure that was an allusion by Prachett: you're not supposed to think like Vimes. His books always have layers of meaning.
Leave of the white. I'd say he sees issues in black. He's a stark cynical copper who has seen anything. A lot of his internal monologue talks about how he wants to unleash 'the beast' but can't because his inner watchmen won't let him.