Still not satisfied?
I don't, of course, take myself to have proved in this FAQ that the practice of making moral claims is legitimate. I've neither the time nor the ability to do that. Excellent philosophers have objected in all sorts of ways to the arguments that I've been giving.
All the same, having articulated the kinds of doubts that students often feel about the kind of first-order moral and political theorising that we do in the lectures and classes, I hope to have shown you that none of those doubts gives us a good reason, by itself, to refuse even to make a start on that kind of theorising.
There are decent, sensible answers to questions such as 'who gets to decide?' and 'isn't this all unrealistic?' and 'isn't it all just a matter of opinion?'. Those questions do much less to put the whole enterprise of first-order moral and political theory in doubt than those who articulate them typically suppose. In order for them to have any seriously worrying import for those of us who think it's OK to go around making and arguing about moral claims, we have to go much deeper into political and moral philosophy or metaethics.
For that reason, I think that the presumption that it's OK, which I operate with when I'm teaching political philosophy, is safe for now. I encourage you, however, to click on the 'further reading' link below if you're interested in pushing the matter a bit further and finding out what some of those excellent philosophers I mentioned have to say.
If you think I've missed one of the standard sources of unease about my assumption that it's OK to do political philosophy as it's normally done, I'd be grateful if you could let me know so that I can add it to the FAQ. Other comments and criticisms are also welcome.
Otherwise, I hope you'll let the assumption stand for the purposes of the lectures and classes that you take in political philosophy. Objections are, as ever, welcome, but if you now think that your objections are best focused on the course's content rather than on its metaethical assumptions, then this FAQ has done its job.