Various news outlets (here and here) have picked up the story of David Epstein, a 46-year-old professor at Columbia University who is accused of having a “consensual” incestuous relationship with his 24-year-old daughter.

I find the public response to cases like these (see also here) to be quite fascinating. Everyone says, “Eeeew.” Conservatives say, “Prosecute!” Liberals say, “Disgusting, but we have no right to interfere.” William Saletan at Slate has tried to argue a middle position.

There are two issues at the heart of our society’s debates about sexuality. The first is whether sexual behavior is in its essence a social act–and by that I mean, the concern of society. The second is the pragmatic question of whether society can effectively regulate sexuality, and whether it should be done by government or by free associative (or dissociative) choices by individuals.

For Christians, it seems hard to escape the fact that biblical sexuality is a social concern, not a private matter. Sexual expression has social implications and should be regulated.

Practically, though, how should a secular government (or, more complicatedly, many secular state governments) encourage socially productive sexual behavior and discourage socially destructive behavior? If biblical standards regarding sexuality are not the standards we choose to uphold, what is the alternative standard?

If the social standard is just pragmatics, you can end up going down some weird lines of reasoning. If the danger of incest is birth defects in children, the government could require those engaging in incestuous sex to be sterilized. Or, perhaps the government could publish a list of HIV-positive people on the Web so that potential sexual partners could make informed decisions. I’m sure there’d eventually be an app for that….

All this to say: when we pervert God’s wonderful gift of sexuality, we end up tying ourselves up in knots trying to deal with all the social, political and personal consequences.