Stephen Barr has a good article in First Things about moral relativism (via Keith Burgess-Jackson). He’s responding, in part, to Robert Miller’s article - which is also worth reading. I think Barr is basically right. He explains well how modern relativsm emerged from positivism and its effect on public morality and political discourse. Barr has a philosopher’s gift for picking out key nuances in complex arguments and this article puts that skill on display.

[W]hile positivism may be discredited among philosophers, it has left a deep mark on how many people think. They are now much more unsure of anything that cannot claim to be “scientifically” demonstrable. They have been well tutored to distrust their own intuitions as possibly naive… [T]hey have become very unsure of the possibility of knowing much really and for sure about many matters on which people in the past were fairly confident.

Therefore, morality tends to be conceived of not only in consequentialist terms but also in terms of physically measurable consequences. Before some manner of child-rearing can be confidently asserted to be harmful in its consequences, there must be scientific studies proving that it leads to poor performance in school, or less financial success later in life, or obesity, or something that is quantifiable and measurable. Is adoption by gay couples wrong? Show us the statistical evidence of harm done. What is wrong with teenage promiscuity? Venereal disease and unwanted pregnancies. That is measurable. Those are publicly verifiable facts. Anything else has to do with your “values” and is therefore between you and your God, priest, minister, et al., but of no possible concern to me or to the public at large.

Anything that is not “scientifically” demonstrable is suspected, even by ordinary people, of being mere “old-fashioned” prejudice, custom, taste, cultural preference, and so on. “Well, I’m old-fashioned, but I think . . . ” People do still have some strong moral feelings, and at some level they suspect and want to believe that these are not just feelings, but they also suspect that perhaps in many cases they are.
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Often, I suspect, when people assert that they or others have “rights” they are not making claims about an objective moral order that grounds those rights. What they have in mind is the idea that, in many areas of behavior, it is impossible really to know what is right and wrong (since there is no scientific way to settle the matter), and indeed there may not be an objective right and wrong, and consequently no one is in position to make rules for everyone else on those questions. They say “I have a right” but really mean “It’s none of your business,” “It is my private concern,” “Keep your rosaries off my ovaries.” Rawls? Never heard of him; just mind your own damn business and stop trying to impose your rules on me. That’s what they mean by rights. Of course, implicit in these “arguments” may be the premise that people ought to mind their own business. But that simply shows that it is impossible to be an absolute relativist.

Read the whole thing. I recently bought Barr’s Modern Physics and Ancient Faith. I’m hoping to get it to this summer.