For years, saying that men and women, and that boys and girls are different, has been viewed as an act of aggression in many of America’s most elite sectors. Yesterday, the Supreme Court treated it as what it is: the truth. In upholding West Virginia’s and Idaho’s laws barring males from female sports, the Court held that a state “may maintain women’s and girls’ sports for biological females.” The reasoning was almost startling in its obviousness — and a fact of nature and commonsense that would have been unquestioned even two decades ago. Given the inherent physical differences between the sexes, separate teams reduce injury and secure fair competition. This is not bigotry. It is biology, and it is, at its heart, justice. Justice Thomas, concurring, went to the root of the issue that the majority only gestured toward, and he did so contra the prevailing legal methods so fashionable today. The official positivist story is that judges exclude moral considerations from their rulings. The reality is that all judges operate from moral premises — inevitably so, often quietly, and in the background — and getting the morality right is no small matter. And Justice Thomas got it right. Sex, he wrote, is immutable and binary; men and boys with gender dysphoria are not women and girls, however sincerely they believe otherwise. That is as clear a declaration of human ontology and teleology as you will ever see in a Supreme Court ruling. That is the deeper victory here — a victory tethered to natural law. The Court did not merely side with the girls who watched a male claim their state shot put title. It sided, however modestly, with reality itself. When reason, nature, the common good, and the law converge, truth wins. That is moral sanity, and it has been in short supply. But a ruling that vindicates the meaning and reality of sex is also a fitting occasion to warn my own side against abusing it. For even as conservatives rightly celebrate the Court’s recognition that sex is real and weighty, a faction on the right has spent recent months committing the mirror-image error — treating sex as though it settles questions it has no business settling. The target has been Justice Amy Coney Barrett, and yesterday’s ruling on birthright citizenship is putting her gender in the crosshairs once again. Disagree with her jurisprudence on immigration and birthright citizenship all you want; that’s your prerogative. But discrediting her reasoning by appeal to her sex, or to her status as an adoptive mother — as some now do — is a category error. It is also textbook Bulverism, C.S. Lewis’s name for the trick of explaining why someone is wrong without first bothering to show that she is wrong: “you only think that because you’re a woman.” A legal argument is sound or unsound on its own terms. The sex of the one making it has no bearing on whether it tracks with the truth. The intellect’s apprehension of reality is not indexed by sex; the human mind, male or female, is equally capable of grasping what is. Truth answers to human nature’s fittedness to reality as such — not to truth qua sex. That sex carries real teleological weight for vocation and embodiment is entirely true, and entirely beside the point here. The adoptive-mother line some use to discredit her is even worse, because it isn’t even about her reasoning. It infers bias from biography. A judge’s conclusions stand or fall on her construction of the law — for good or for ill — not on the shape of her family. Attack the argument, or concede you haven’t got one. I’m no expert on the Constitution and immigration, and Justice Barrett may well be wrong. If she is, make the case from text and history — not from sex. And here is the irony the moment lays bare. The progressive who insists a male can be a female denies that sex means anything fixed at all. The populist who insists Barrett rules as she does because she is a woman insists that sex means everything — that it skews the very operations of the intellect. Both are failures of the same faulty anthropology. Both refuse to see the human person as he and she actually are: embodied, sexed, and therefore genuinely different in vocation and form; yet equally rational, equally answerable to reality, equally made in the image of the God who is Truth. To suggest otherwise is to deny the ontological and epistemological equality of men and women as image-bearers of God. The Court got the first half right today. Sex is real. It is given. It is not ours to redefine. The task now falling to conservatives is to hold the second half with the same conviction: that honoring the difference between men and women never requires pretending a woman cannot think or that her status as an adoptive mother necessarily colors her rulings. A movement that learns to say sex is real will have won an argument. A movement that also learns when sex is beside the point will have learned wisdom. *** Andrew T. Walker is associate professor of Christian Ethics and Public Theology at The Southern Baptist Theological Seminary and managing editor of WORLD Opinions. He is a fellow at The Ethics and Public Policy Center.