Lefties and virtues

In an email discussion a Lefty said:

The religious right believes promiscuity is bad because the Supreme Being and Creator of the Universe doesn’t like it, never has and never will. The left believes it’s good or bad depending on the consequences on this earth, in this lifetime, and those are going to change over time. The left’s morality comes from the ground, not from the sky.

Between liberals, fundies, fideists and bad education that’s quite a common view here in America. My response:

If Catholics are part of the religious right then at least one wing of the RR thinks natural law is enough to cover the point. Natural law says promiscuity is at odds with a good life here and now as the good life can be understood without reference to any specific revelation. From that point of view to attempt to deal with something that touches us as closely as sex by a sort of technical and administrative analysis of the kind the Consumer Products Safety Board might apply to microwave emissions seems inhuman and bizarre.

The problem, I think, is that the Left sees man as self-created, at least socially and morally, and on that view things like natural law and virtue make no sense. Instead your good becomes getting what you want, or maybe self-assertion simply as such. That view doesn’t work, though. People want something more than getting what they want, they want to take part in a world that makes sense in a way they don’t simply make up themselves. Also, you can’t bootstrap the self. If you aren’t already something to start with (that is, by nature) then you aren’t going to be able to create yourself ex nihilo. So your self-assertion will have nothing to assert, and very likely will end up asserting nothingness through destruction.