Wrapping up the Guards! Guards! reread, I hit this passage from Vetinari to Vimes and have to pause to snicker because Vetinari is just so damn young here:
“A great rolling sea of evil,” he said, almost proprietorially. “Shallower in some places, of course, but deeper, oh, so much deeper in others. But people like you put together little rafts of rules and vaguely good intentions and say, this is the opposite, this will triumph in the end. Amazing!” He slapped Vimes good-naturedly on the back.
“Down there,” he said, “are people who will follow any dragon, worship any god, ignore any iniquity. All out of a kind of humdrum, everyday badness. Not the really high, creative loathesomeness of the great sinners, but a sort of mass-produced darkness of the soul. Sin, you might say, without a trace of originality. They accept evil not because they say yes, but because they don’t say no. I’m sorry if this offends you,” he added, patting the captain’s shoulder, “but you fellows really need us.”
“Yes, sir?” said Vimes quietly.
“Oh, yes. We’re the only ones who know how to make things work. You see, the only thing the good people are good at is overthrowing the bad people. And you’re good at that, I’ll grant you. But the trouble is that it’s the only thing you’re good at. One day it’s the ringing of the bells and the casting down of the evil tyrant, and the next it’s everyone sitting around complaining that ever since the tyrant was overthrown no one’s been taking out the trash. Because the bad people know how to plan. It’s part of the specification, you might say. Every evil tyrant has a plan to rule the world. The good people don’t seem to have the knack.”
Ah, yes, sir: because you are very evil, what with the assuming power largely, as far as I can tell, because you're offended by how poorly the system works; you whose first career move was to work to create stability in the city in a bid to minimize blowback, you who are above everything else practical and focused on utilitarianism. Uhhuh.
He's so young. Almost everyone in Guards! Guards! is, of course--Carrot with his law book most obviously--but with Vimes the alcoholic depression and the despairing cynicism has its hooks in so deeply that the overall impact is to see that. By contrast, moving from Making Money to Guards! Guards! reveals a Vetinari who is almost embarrassingly green relative to the Ventinari who trains Moist: he is constantly making arrogant mistakes (ie "there's no dragons, that's nonsense") that his older self would be mortified to see, and then there's little pronouncements like this.
And for that matter, Vetinari himself should know full well that his "bad people" don't necessarily bother with much planning, either; just look at Mad Lord Snapcase. It's possible to view this through a Doylist lens--we just know a lot more about the history of Ankh Morpork by later books than Pterry did when he was writing this one. But I like to integrate Watsonian interpretations into my readings of the text, and so I enjoy thinking about this as partly a bid to undermine any support Vimes might be lending to any bids for power Carrot might make. After all, Carrot hasn't made any commentary about his sword one way or another; it's unclear to both Vetinari and the reader whether Carrot knows about the long lost heir of the city thing, and even more unclear what Carrot might choose to do in the absence of a giant flaming dragon having declared itself king.
Vetinari is in a fairly precarious place in this book, having been Patrician for only a relatively short time as far as I can tell, and after all there has just been an extraordinarily popular movement to replace the entire office of the Patrician with a hereditary king. If Carrot chose to, he could make life quite difficult for Vetinari: he might not win a theoretical power struggle, but he could certainly cost quite a bit of political capital and considerable public belief in Vetinari's ability to create stability. And Vimes, as Carrot's immediate supervisor and erstwhile human mentor, is the single person most likely to be able to influence Carrot away from that leg of the Trousers of Time.
It's an interesting way to plea for the support of a man like Vimes, I'll put it that way. It's wholly truthful and quite earnest, and it's not particularly manipulative: if anything, it paints Vetinari in quite a lot worse light than he could make a reasonable claim to being. It also avoids tugging on at least one equally truthful argument that could be expected to tug on Vimes' own sentiments: Vetinari is, for all his flaws and autocratic opinions, at the very least not a king. While he holds power, there will be no monarchs, no Lorenzo the Kinds to claim divine right to rule. I suppose it's also possible that Ventinari simply didn't know, of course, but--it's such an interesting little speech from a character perspective.