More at http://philosophytalk.org/shows/it-all-relative.

We've all heard a disenchanted teenager claim that everything is relative and that there is no absolute morality or truth. Of course, there seems to be something wrong with that; isn't the relativity of everything then an absolute? Relativism has appeared throughout philosophy since the ancient Greek Sophists. Proponents of relativism argue that some central element of thought, experience, evaluation, or even reality is somehow relative to something else. Does that mean that we merely obey a code that has no inherent value? John and Ken avoid absolutes with Paul Boghossian from New York University, author of "Fear of Knowledge: Against Relativism and Constructivism."