In fact (as Medieval jurists were well aware), one man’s right is simply another’s obligation. My right to free speech is others’ obligation not to punish me for speaking; my right to a trial by a jury of my peers is the responsibility of others to maintain a system of jury duty. The problem is just the same as it was with property rights: when we are talking about obligations owed by everyone in the entire world, it’s difficult to think about it that way.
