In the second volume of Robert Jenson’s Systematic Theology (2001), he discusses the Ten Words. His treatment of “Thou shalt not commit adultery” is profoundly important.

Sexuality is the intersection of sensuality and reproduction. Sensuality is “the sheer fact that the subject is drawn to an object; it is captivation by touching and seeing and hearing and smelling and tasting” (88). We’re often asexually sensual – when we’re stopped in our tracks by a sunset, the aroma of a flower, an aria.

That sex has to do with reproduction is, or should be, obvious. Jenson calls it God’s “most humourous idea” that the human race perpetuates itself through “an act performed between humans” with bodies “distinguished from and directed to one another by sheer plumbing” (89).

Sexuality is “the location of the most intense sensuality of which we are capable in the plumbing by which humanity is divided into two mutually fitted kinds” (89). Sexual attraction and pleasure captivate us, and this captivation is centered in our reproductive “plumbing” as male or female.

We’re always “there for one another” through our bodies. We are social beings because our bodies connect us with each another, in speech, touch, sight and smell.

If we were not sexual beings, our social life might be a matter of choice and contract. We could associate or not, as whim dictated. Sexuality ensures that the communal form of our humanity isn’t an “ideal or demand.” Sexuality roots our directedness to one another in “a fact about us” (89), a fact about our bodies.

This means, Jenson argues, “the family is the essential institution of any community. . . . The institutionalization of sexuality is the foundation of all communal institutionalization” (90).

If that’s true, our late modern refusal to institutionalize sexuality is insane. We work on the principle we learned from John Stuart Mill: “What someone does in bed is not the law's business, so long as no one is hurt.”

The truth is the opposite: “what I do in bed is the area of my action in which the community has the most urgent interest, the area for which it must legislate if it is to legislate at all” (90).

Our laws are failing the “reality test” (91). And that is dangerous. “A sexually anarchic society cannot be a free society,” Jenson warns. “No society can endure mere shapelessness; when the objective foundation of community is systematically violated the society must and will hold itself together by arbitrary force” (91).

Jenson was writing before Obergefell, before the rise of aggressive transgenderism and sexual fascism. One might call him a prophet, but Jenson is modest. He claims only to record “what is visibly happening in late-twentieth-century Western societies” (91).