§. 186. The conqueror, it is true, usually by the force he has over them,
compels them, with a sword at their breasts, to stoop to his conditions, and
submit to such a government as he pleases to afford them; but the inquiry is,
what right he has to do so? If it be said they submit by their own consent,
then this allows their own consent to be necessary to give the conqueror a
title to rule over them. It remains only to be considered whether promises,
extorted by force, without right, can be thought consent, and how far they
bind. To which I shall say, they bind not at all; because whatsoever another
gets from me by force, I still retain the right of, and he is obliged presently
to restore. He that forces my horse from me ought presently to restore him, and
I have still a right to retake him. By the same reason, he that forced a
promise from me ought presently to restore it — i.e., quit me of the
obligation of it; or I may resume it myself — i.e., choose whether I will
perform it. For the law of Nature laying an obligation on me, only by the rules
she prescribes, cannot oblige me by the violation of her rules; such is the
extorting anything from me by force. Nor does it at all alter the case, to say
I gave my promise, no more than it excuses the force, and passes the right,
when I put my hand in my pocket and deliver my purse myself to a thief who
demands it with a pistol at my breast.