The Supreme Court opens its new term Monday with six nominal conservatives appointed by Republican presidents. But conservatives have been shaken in their confidence that those six will yield majorities on issues that deeply matter. That declining confidence comes along with a serious argument within the conservative family over the nature of “conservative jurisprudence.” Conservatives are united in taking as our coordinates the original meaning of the text of the Constitution. But some of us have argued for “a better originalism,” as opposed what we call the “truncated originalism” that has predominated. We see the latter...

The Supreme Court in Washington, Sept. 3.

Photo: J. Scott Applewhite/Associated Press

The Supreme Court opens its new term Monday with six nominal conservatives appointed by Republican presidents. But conservatives have been shaken in their confidence that those six will yield majorities on issues that deeply matter. That declining confidence comes along with a serious argument within the conservative family over the nature of “conservative jurisprudence.” Conservatives are united in taking as our coordinates the original meaning of the text of the Constitution. But some of us have argued for “a better originalism,” as opposed what we call the “truncated originalism” that has predominated. We see the latter as detached from the understanding that the American Founders, the true originalists, had of the moral ground of the Constitution and laws they were shaping.

Having simmered a long time, this argument was heated to a boil by Justice Neil Gorsuch’s opinion in Bostock v. Clayton County (2020). In that case, Justice Gorsuch (joined by Chief Justice John Roberts ) broke away from his conservative colleagues on the issue of “transgenderism.” Somehow Justice Gorsuch found that the Civil Rights Act of 1964, in barring discriminations based on sex, also barred discrimination against people who claim that in their own sense of themselves, they had changed the sex marked in them by their organs of reproduction, the structure of their bodies and their hormones.

Conservatives were in disbelief and outraged that Justice Gorsuch, a self-proclaimed “textualist,” would extract such a meaning from the text. It’s hardly imaginable that the lawmakers who enacted the Civil Rights Act thought they were protecting from discrimination persons who were crafting their own view on what their sex was.

But merely appealing to dictionaries about the meaning of “sex” in 1964 wasn’t an adequate rebuttal. The challenge could be answered most decisively by appealing to the meaning of sex that will never change—to those objective and inescapable truths, grounded in nature, about the way we are constituted, of necessity, as males and females. Yet for the past 50 years conservatives have been treating it as anathema to move beyond the text to truths that were there before the Constitution—what Chief Justice John Marshall called the anchoring “axioms” of the law, and Alexander Hamilton called “primary truths . . . upon which all subsequent reasonings must depend.”

Conservatives, however, have even taken it as a code of conduct to steer around the questions of moral substance at the heart of the cases. In Obergefell v. Hodges (2015), the case that legalized same-sex marriage, Antonin Scalia, one of my favorite justices, wrote in dissent that “it is not of special importance to me what the law says about marriage” but “it is of overwhelming importance . . . who it is that rules me”—namely “a majority of the nine lawyers on the Supreme Court.”

That question of jurisdiction, of who has the authority to decide, is always critical, for it reaches the moral logic underlying the separation of powers. In Boumediene v. Bush (2008), Justice Anthony Kennedy led the court in extending its reach into the battlefields. That move violated one of the deepest principles of the American regime: that the safety of the American people cannot be put in the hands of unelected officers, whether in Westminster or in the courts, who bear no direct responsibility to the people whose lives are at stake.

Yet conservative jurisprudence has too often been distracted in a stylish way by procedural formulas that divert the judges from the substance of the cases. And so we’ve heard for years that federal judges can’t declare a right to abortion because abortion is nowhere mentioned in the Constitution. But neither is marriage mentioned in the text, and no conservative justice now would call into question Loving v. Virginia (1967), which struck down the laws that barred marriage across racial lines. As Notre Dame’s Gerard Bradley observed, the federal government has had ample reason to deal with the question of abortion—say, in the military and diplomatic outposts abroad or in the District of Columbia—despite the Constitution’s silence on the subject.

In Roe v. Wade (1973), the lawyers defending the abortion laws of Texas drew on the most updated data from embryology, woven with principled reasoning, to show that the offspring in the womb had been nothing other than human from its first moments, that it was never merely a part of the mother. These lawyers acted, we might say, “naturally”: they sought to show why the laws of Texas were “justified” in casting their protections and displacing the personal freedom of a woman to destroy that small human being who was uniquely vulnerable to her care—and her power.

But none of that rich material made its way into the dissenting opinions by Justices Byron White and William Rehnquist, who were content to rely on the point that abortion was nowhere mentioned in the Constitution. If that is all the court can say—if there is no recognition of a child in the womb as a human life—then why would any state be justified in barring a pregnant woman from being rid of it? And why should she lose that freedom if she travels to another state? But if that offspring is never anything less than a human being, why should the court not engage the power it has used in the past when the protections of the law were withdrawn from a class of human beings and citizens within the separate states? A court that can’t settle its judgment here is simply giving us another chapter in a continuing story of incoherence.

This is an argument, as I say, “within the family” of conservatives. Edmund Burke offered an “Appeal From the New to the Old Whigs,” and we would now make an earnest appeal to our friends, the new originalists, in the name and teaching of the old.

Mr. Arkes is a professor of jurisprudence emeritus at Amherst College, founder/director of the James Wilson Institute on Natural Rights and the American Founding.

Wonder Land: Justices Stephen Breyer and Amy Coney Barrett share at least one opinion: The Supreme Court is in trouble. Images: Pool/AFP/Getty Images Composite: Mark Kelly The Wall Street Journal Interactive Edition