Over the weekend we introduced you to pink professor Kwame Anthony Appiah.

Click here to read part one of Appiah's exchange with our editor. Today's conclusion picks up where Saturday's installment left off.

In today's piece Appiah offers some more tips on how to be a cosmopolitan, chats about gay marriage, why Obama's a better candidate than Clinton and tells us why he doesn't give two hoots about the Anglican's ongoing gay debate.

Andrew Belonsky: One of things that comes up in your book - not essentially, but is mentioned - is gay marriage. You write that the reason there's such a fever-pitched battle is that both sides of the debate care very deeply about this institution.

Anthony Appiah: Yes.

AB: I think that can also be split within the gay activists. What exactly is the importance of the institution of marriage? Are people concerned with the equality - with equal rights - or are people concerned with the institution? That's something that I think about a lot - I don't personally care right now about getting married, but if it's something that people want to do, it should be allowed, obviously.

AA: Sure. That's my view. We should respect the sanctity of marriage as a legal institution. As far as religious practice goes, the public view says, "Well, there are religious practices in our society and societies that have religious tradition." Gay friendly Anglicans should be arguing with the Anglican church about how they treat people, but not being an Anglican, I don't think it's much of my business. As far as the state goes, very strong norms of equality are appropriate. If you provide an institution for one kind of pair of people, I think you should provide it for all pairs. It should be freely available in a non-discriminatory way. A state owes equal respect to all citizens. The exclusion of gay couples from access to marriage is just a manifestation of a failure of equal respect.

AB: What do you make of the federalist argument here in the United States? Say the people in Missouri, they vote to define marriage as one man and one woman, because that's what they value, what they perceive to be moral, but the people in Kentucky say, "We should legalize gay marriage". What does that do to American democracy, in your opinion?

AA: Well, here again you have to make a distinction between the legal issues and the ethical or moral issues. If the point of the Missouri legislation is to deny equal respect to gay couples - I don't care if it's constitutional or not - it's wrong. Whether as a matter of politics it's better to decide these things by state or by federal legislation, I don't have a big view about that, but I think the denial of this bundle of marriage rights is a breach of fundamental equality. It's arguable, but it's so inconsistent with the federal constitution, because the federal constitution has a very strong equality norm in it. Now, the way you decide those questions in the United States is you send it to nine people in Washington and they think about it for a bit and declare their view. I don't know if whether those nine people would accept that [breach] argument right now. Probably they wouldn't, because a significant number of them were elected by people who were trying to pick conservatives. So, we might lose that argument at the Supreme Court right now.

AB: Right.

AA: It's true that those people have a special place in our constitutional system to decide what the law is right now, but I can still appeal the constitutional value even when the court doesn't have to recognize them. Before Brown v. Board of Education, but after Plessy, when the Supreme Court held the view that separate but equal was consistent with the Constitution, a person who said, "I'm sorry, the court was wrong, there is a fundamentally equality norm that's breached here and you can't have separate, but equal" - that person was entitled to make an argument about the interpretation of the constitution. The Supreme Court gets to decide the matter within the system, but the Constitution belongs to all of us. It doesn't just belong to those nine people. There is a fundamental equality norm in our system and that fundamental norm is denied by people who allow a bundle of marriage rights to straight couples and deny them to gay couples. I think that's wrong.