The second part of Hart’s article makes an ambitious claim that many commonly accepted rights logically entail one natural right, the equal right to be free. What does “natural” mean? It means rights that are not derived from any social interaction. Rights derived from promises, by contrast, are derived from the interaction of making a promise.
In brief, Hart tries to show how the way we use three kinds of rights doesn’t make any sense unless we also believed in that natural right. There is no better way of explaining our invocation of those other rights. “General” rights invoke the equal right to be free directly; that is the best explanation of what we mean when we assert that we have general rights. The two classes of special rights invoke the equal right to be free indirectly. For promises, the equal right to be free generates a hurdle that rights must cross to be justified: the obligation corresponding to the right has to be consistent with the equal right to be free. Mutual restrictions restore equal freedom when some people give up their freedom to produce goods that everyone can enjoy.
The idea is that natural rights are a bit obscure. We picked on the natural law tradition to start of the term for that very reason. If Hart succeeds in showing that apparently less obscure practices surrounding rights depend on natural rights, then he will have cleared away some of the obscurity. He will also have shown that we probably can’t do without natural rights, at least, without giving up quite a lot that we otherwise believe in.
Alas, I don’t think the inference works. The sticking point concerns the equal distribution of the right to be free. I don’t think that’s logically entailed by the other rights. All that is necessary is that people have some freedom, not an equal distribution of it.
Our discussion centered around whether my examples of unequal rights to freedom were realistic. Several people pointed out that there can be a big gap betwen a person’s nominal freedom to accept or refuse an offer and the real possibility of doing so. This renders voluntary obligations across class lines in deeply hierarchical societies suspect.