Is Incest a Constitutional Right?

Last month, David Epstein--a professor of political science at Columbia University--was charged with having an incestuous relationship with his daughter. According to news reports, Epstein (age 46) began the affair in 2006 when his daughter was 21 years old and then stopped in 2009. If he is convicted, he could be in jail for up to four years.

This case has provoked an interesting debate among constitutional law scholars as to whether punishing Epstein for his incest would violate his constitutional rights. In 2003, the U.S. Supreme Court decision in Lawrence v. Texas struck down state criminal laws against homosexual sodomy as an unconstitutional violation of liberty. The reasoning in that decision seemed to be that consenting adults have a right to engage in any sexual behavior in private that does not harm anyone else. That reasoning would seem to extend to incestuous sexuality between consenting adults, and therefore punishing Epstein and his daughter would seem to violate their constitutional liberty. If homosexuality between consenting adults is constitutionally protected, then why isn't incest between consenting adults also protected by the Constitution?

We might think that incest is harmful because of the risk of offspring with genetic defects. But if Epstein and his daughter practiced safe sex, of if she is his step-daughter, or if he has had a vasectomy, then there would be no genetic harm.

We might also think that children can be exploited by parents in such cases. But here the daughter apparently consented to this as an adult.

William Saletan at Slate has argued that we can rightly condemn and punish incest--even between consenting adults--because it destroys the structure of family life by introducing an explosive sexual tension. This then would provide a "rational basis" for laws against incest as constitutional, and this would be consistent with the Lawrence decision, because homosexuality does not threaten family life the way incest does.

Nevertheless, Saletan doesn't believe that Epstein should be locked up.

I wouldn't prosecute David Epstein. It isn't necessary. The incest taboo is strong enough to withstand the occasional reckless fool, and I don't want cops poking around in people's sex lives. But incest is wrong. There's a rational basis to forbid it. And we shouldn't be afraid to say so.

Matthew Franck agrees with Saletan's family-structure argument for why incest is wrong. But he disagrees with Saletan on three points.

First, Franck thinks we need a legal enforcement of our moral condemnation of incest.

Second, he thinks that this contradicts the reasoning in the Lawrence decision, which really does make the mistake of giving constitutional protection to any sexual activity between consenting adults, which would include not only incest, but also polygamy and bestiality.

Third, he thinks that legalizing homosexual marriage could be just as destructive of marriage and family life as incest.

Franck agrees with Robert George that our marriage laws should enforce the norms of "real marriage" as a natural union of husband and wife for the procreation and care of children. Consequently, attempts to legalize homosexual marriage or incest should be rejected as contrary to the human nature of marriage and family life as the foundations for a good social order.

Thus, like George, Franck implicitly appeals to a conception of natural law as rooted in human biological nature. But he never explains--as I would--that that biological nature can be understood as a product of Darwinian evolution.

As I have argued in previous posts, the incest taboo illustrates the evolutionary nature of morality, particularly as elaborated by Edward Westermarck's Darwinian account of the incest taboo.

If the incest taboo and traditional marriage are deeply rooted in our evolved human nature, then we should expect that those natural propensities will be expressed as cultural norms that arise spontaneously in civil society. But whether those cultural norms must be legally enforced by governmental coercion is a matter of prudential judgment.

Conservatives like Franck and George think that moral norms like the incest taboo and traditional marriage will collapse if they are not enforced by the coercion of a bureaucratic state. But if these norms really are deeply rooted in human nature, why shouldn't we expect them to be expressed in the customary order of civil society even without legal enforcement?

I will elaborate these points in connection with George's arguments about "real marriage" in my next post.

Some of my posts on Westermarck and incest can be found here, here, here and here.