The Darwinian Science of Same-Sex Marriage in Thomisitc Natural Law

On April 4-6, I will be lecturing at Saint Vincent College (Latrobe, PA) as part of a conference on "Science, Human Nature, and Public Policy."  Of the nine speakers for this conference, I foresee that I will be the only one arguing in favor of the modern scientific understanding of human nature as applied to public policy.  As often happens with me at such gatherings of conservatives who think modern science is the enemy, I will probably be everyone's punching bag.  This is likely to be similar to what happened a few years ago at a conference at Berry College organized by Peter Lawler on "The Science of Virtue."  I wrote about it here.

I will write a paper entitled "The Darwinian Science of Same-Sex Marriage in Thomistic Natural Law."  I will defend seven claims.

1. Thomistic natural law is rooted in biological science, because natural law corresponds to four levels of the natural inclinations of human biological nature.  (I have a post on that here.)

2. Darwinian science largely confirms this four-leveled conception of human nature.  (I have posts on that here and here.)

3. The biological character of Thomistic natural law is clearly manifest in the natural law of marriage.  (I have a post on that here.)

4. While Darwinian science largely confirms Thomas's natural law of marriage, it denies Thomas's claim that homosexuality is "contrary to nature" as indicated by the fact that no nonhuman animals show homosexuality.  (I have posts on that here and here.)

5. Justice Anthony Kennedy's opinion in Obergefell v. Hodges (2015) favoring same-sex  marriage as a constitutional right is implicitly, although not explicitly, a Thomistic natural law argument.  (I have posts on that here and here.)

6. The debate over same-sex marriage turns on empirically falsifiable predictions about whether same-sex marriages can satisfy the natural inclinations of marriage without harming children or weakening heterosexual marriage.

7. At this point in history, the scientific study of the relevant empirical evidence is inconclusive on this debate over same-sex marriage; and we might need 15-25 years of experience with legalized same-sex marriages to give us the evidence we need to settle the debate.  (I have some posts on this here, here, and here.)

Some of my material for this paper will be drawn from a paper I prepared two years ago for a symposium on "Law as a Guide to Justice" at the University of Cambridge.  I wrote about that here.

At the Saint Vincent conference, Mark Regnerus will be one of the speakers.  He is the author of a controversial study claiming that there is empirical evidence that same-sex parenting harms children.  I have written a post on that, and in my next post I will say more about it.