Conquest and rebellion are two violent ways of gaining control of the state. On the face of it, they are different than the method of forming a state presented in chapter 18.
Hobbes argues that there really isn’t a significant difference between a state whose origin is violent, which he calls the commonwealth by acquisition, and one whose origin is peaceful, which he calls the commonwealth by institution.
Dan made a good case for thinking that Hobbes exaggerated the similarities between the commonwealth by institution and the commonwealth by acquisition. Among other things, the future subjects have a lot more choice about who will be the sovereign in the former case. And they’re much less likely to be stuck with someone whose qualities are unpleasant. How unpleasant? Well, the conquerors threaten their lives. If they’re smart, they’ll appoint sovereigns who are less … pushy.
I think Dan’s right. There’s no denying that those are differences. The question is how much they matter. I’m not certain how to resolve that. In ordinary moral thinking, we draw a distinction between agreements made under duress and hard choices; the former are invalid, the latter are valid, if sometimes regrettable. But where we draw the line is a mystery and Hobbes denies that our ordinary moral rules apply to this sort of case anyway.
One thing that Hobbes could say is that it would be very much to our advantage to be able to appoint a conqueror as a sovereign. Otherwise, how could civil wars be settled, short of wiping everyone who had been on the losing side?
Officially, no. But there is a back door.
The back door is the “true liberty of a subject,” the right of self-defense. Rebels have this just like anyone else. So long as they aren’t pardoned of their crimes, they can continue their rebellion, even to the point of winning.
Of course, they had no right to begin it in the first place. But once the die has been cast, they’re permitted to go all out.
It doesn’t sound like much. But for some of his contemporaries it was enough to brand Leviathan as a “rebel’s catechism.”** See Curley’s Introduction, p. xxxviii.