Civilians? Or Soldiers?

Terry Pratchett's latest, Snuff, is a Vimes novel. That means there's a lot of action, but also a lot of thinking - about what makes us human (for lack of a better word; even Angua thinks about that), and also what makes civilization work. Here's one of my favorite bits:

It always embarrassed Samuel Vimes when civilians tried to speak to him in what they thought was "policeman". If it came to that, he hated thinking of them as civilians. What was a policeman, if not a civilian with a uniform and a badge? But they tended to use the term these days as a way of describing people who were not policemen. It was a dangerous habit: once policemen stopped being civilians the only other thing they could be was soldiers.