Is there a fundamental conflict between those who base politics on revelation and those who base politics on reason alone?
"I haven't met all that many people who base politics on reason alone. Even if they think they do, they're very often taking for granted a good many hidden moral and even spiritual assumptions. Reason alone is often identified with managing a variety of people's self-interests and that gets you so far, it doesn't get you to the point where politics turns into something a little bit bigger than just the calculation of self-interest, when it understands something about obligation outside the immediate, when politicians act for the sake of the poor elsewhere or for the sake of the environment generations on, or whatever. I don't think that's covered just by classical accounts of self-interest, and in that sense I don't think it's just about reason; there's something about vision and moral energy in there somewhere. So I'm not sure I'd accept an absolute difference between revelation and reason in that connection."
(Rowan Williams, Faith & Politics Q&A. Emphasis his.)