I listened with interest to a large chunk of the parliamentary debate on same sex marriage the other day. I was impressed with the sincerity, care and concern displayed by people (in the most part) on all sides of the debate. But nobody answered my question. Nobody addressed the thought that kept popping into my mind with almost every speech. Time and time again MP’s would stand and assert things like ‘marriage is about love’ or ‘marriage is a man-made institution’ or ‘marriage should be protected.’ And all the while I’m listening to the (often unchallenged) assertions and asking my own questions like ‘who says?’ and ‘where did you get that from?’ It seems to me that the most important and fundamental question in any moral debate is the epistemological question – ie. ‘how do you know?’ or ‘where did you get that idea from?’ or ‘who says?’ or ‘how do you know you’re opinion is the right one?’ Is it simply a case of majority rule? History has shown the majority of one generation may disagree with the majority of another. Is it reason or feeling or experience? Again one man’s reason or feeling or experience differs from another’s. So how do we tackle moral questions. Is it some form of relativism where he who shouts loudest and longest wins. Or could we use some of kind of ultimate moral authority? If so where would you find such a thing? Perhaps it’s unreasonable to expect parliament to spend all their debate time in philosophy but when it gets down to it the epistemological question is surely the most fundamental when it comes to determining our answers to moral questions. Failure to address them is failure to persuade with integrity.