The consensus among legal scholars and media observers is that we have at last arrived at the triumph of “originalism” in our jurisprudence, the culmination of a legal counter-revolution decades in the making. But there seem to be as many versions or shadings of originalism as there are flavors at Baskin-Robbins. Even when the conservative originalist justices of the Supreme Court agree on a holding and doctrine, the jural anchors and lines of reasoning often differ considerably.

　　Regardless of the lack of a clear center point, the triumph of originalism represents the end of the free-wheeling, result-driven “due process” jurisprudence of the Warren Court, arguably rolling back the judicial odometer to before the “legal realism” of the early twentieth century sanctified the progressive drive for judicial modification of the law to meet “the felt needs” of the time.

　　Originalist interpretations range between what might be called the “40-yard lines” of strict textualism and “original public meaning.” With the conspicuous exception of Justices Clarence Thomas and Samuel Alito, few Supreme Court justices appear to be comfortable anchoring their reasoning explicitly on old natural law doctrines. But there are some clues that the natural law tradition, and its long centrality in practice in the common law, is slowly making a meaningful comeback.

　　A possible indicator of the underlying direction of things comes from an unusual recent paper by Dana Neacsu of Duquesne Law School and Paul Douglas Callister of the University of Missouri–Kansas City School of Law, entitled “The Persistent Treatise,” currently available on the Social Science Research Network. The paper attempts a quantitative longitudinal analysis of the citations of legal “treatises” in federal court cases from 1962 through 2022.

　　There are some classification difficulties with the definition of what counts as a “treatise,” and the results of this study, which the authors admit are tentative and preliminary, would change depending on a different classification scheme. The paper defines “treatise” broadly and narrowly at the same time, with criteria for selection that many readers would rightly consider arbitrary. The starting point for defining a treatise is any work that attempts a systematic organization of the law or major aspects of the law, such as civil procedure. But restatements, hornbooks, texts, casebooks, most multi-author works, and treatments for very specific practice areas are mostly excluded. The authors identify a possible domain of 2,600 candidates to be considered a “treatise,” but settle on just 77 for their statistical analysis.

　　The main finding of the study, and hence the meaning of the title “the persistent treatise,” is that Supreme Court citations of classic or old treatises have been on the rise in the last two decades, after several decades of declining citation. That steady decline began, not coincidentally, in the heyday of the Warren Court era starting in the early 1960s, but reversed trend and started rising toward pre-Warren levels over the last 20 years. Neascu and Callister admit this was an unexpected result. They are not alone in thinking reliance on classic treatises should be increasingly obsolete in the age of Lexis, Westlaw, and other Internet research tools that bid to make treatises obsolete.

　　A sample size of just 77 treatises is likely too small for meaningful statistical analysis, but a wider scope and larger number of treatises might have produced an unwieldy result. One aspect of their findings, however, would stand out even if the study had included a larger number of possible treatises. Several classic treatises of the common law tradition have become important in cases that overrule precedents, most especially Roe v. Wade in the 2021 Dobbs v. Jackson Women’s Health Organization decision.

　　A key dispute central to both Roe and Dobbs was the status of abortion in common law before and at the time the Fourteenth Amendment was enacted. In his opinion, Alito made a strong case that Justice Harry Blackmun, the author of the Roe decision, had misconstrued the status of abortion in common law. Alito’s lengthy counterargument to Blackmun made a point of citing treatises going back to Henry de Bracton in the thirteenth century, along with Sir Edward Coke and Matthew Hale of the seventeenth century, and William Blackstone in the eighteenth century, all of whom Alito calls “the great [or eminent] common law authorities.” These and other older sources informed the positive law on abortion as it existed in 1868, when the Fourteenth Amendment was enacted.

　　More broadly, Neacsu and Callister find that these four classic authors, along with early American legal writers such as Justice Joseph Story and New York Chancellor James Kent, appeared in less than 10 percent of Supreme Court cases in the 1970s, but have risen steadily to over 25 percent in the last decade ending in 2022. By reference, these authors and treatises were cited in nearly 60 percent of Supreme Court cases in the first 20 years of the American republic after 1789.

　　Regardless of which treatises and authors might be plausibly included, these authoritative authors of the common law tradition, Neacsu and Callister conclude, are useful for justifying departures from stare decisis: “The Supreme Court is reemphasizing the early treatise, institutes, and sources of law to great effect, and in a way that supports originalism by returning to the texts of the Founders and the early justices of the court.” Neacsu and Callister think these authors indicate the Court “sees fit to rely on those sources available to the Founders and early Justices of the Supreme Court,” though one might wonder why other classic authors well known to the Founders such as Fortescue, Littleton, and Plucknett are left out.

　　The re-emergence of classic common law treatises looks to be a significant aspect of the story of originalism. But there is no guarantee the classic treatises will be correctly understood or applied.

　　The decline of the classic treatises in the late twentieth century has long been ascribed to the triumph of progressive legal realism along with the result-oriented leftist jurisprudence of the Warren Court era. That era was merely the culmination of the century-long process Stuart Banner described in his excellent 2021 book The Decline of Natural Law: How American Lawyers Once Used Natural Law and Why They Stopped. Banner noted that “to the extent the common law was based on reason, it was a form of applied natural law—universal principles, discernable by reason, applied to specific circumstances of American life.” The Benthamite attack on natural law and natural rights paved the way for the legal realist revolution, which found Roscoe Pound, among others such as Oliver Wendell Holmes, contemptuously rejecting natural law as “Cloudcuckoo-town law.” These progressive scholars and jurists attempted to transform common law reasoning from an orientation toward judge-discovered law to judge-made law. The difference may seem subtle, but it turns out to be crucial.

　　The turn away from natural law and its common law derivatives culminated in the 1938 decision Erie Railroad v. Tompkins, which declared, “There is no federal general common law,” overturning Swift v. Tyson (written by treatise-writer extraordinaire Joseph Story), the 1842 decision that encouraged federal courts to employ a general common law in certain kinds of commercial cases brought under diversity jurisdiction. Justice Antonin Scalia, for one, said good riddance to the idea of a federal common law, supporting instead the slow road toward statutory codification of everything possible. Common law judging, Scalia thought, put too much power in the hands of judges and was undemocratic. In the modern era that discarded natural law, he was correct. Scalia, despite his personal Catholic faith, had no use for natural law in jurisprudence. But in an irony for our present subject, Scalia allowed that “despite the fact that statutory interpretation has increased enormously in importance, it is one of the few fields where we have a drought rather than a glut of treatises,” the last useful one he could think of having been published in 1940.

　　Maybe the old Swift decision got the matter right about the common law (as Michael Greve has argued).A recourse to a federal common law would be a brake on states attempting to tilt the playing field toward in-state interests—the very kind of conflict the Commerce Clause was adopted to prevent. (A good example might be California’s state rules on “humane” pork production that imposes its regulation on farmers in the Midwest. The Supreme Court declined to strike down this legal aggression, deferring remedy to the dormant commerce power of Congress alone.)

　　Beyond the textual argument, though, are the cases like Dobbs and still the many more sudden and recent challenges to the legal buttresses of the administrative state that turn on principles beyond mere textual construction (one thinks of the “major questions doctrine” announced in West Virginia v. EPA). And while most of these cases do not turn on the common law directly, the classic common law treatises are a good source to recover the logic of the law that informs central (but often unstated) principles such as the separation of powers.

　　The re-emergence of classic common law treatises looks to be a significant aspect of the story of originalism, by anchoring new originalist rulings to a much longer and older tradition. But there is no guarantee the classic treatises will be correctly understood or applied. This is not a new problem. Chief Justice Morrison Waite, in his majority opinion in Munn v. Illinois that upheld state regulation of grain elevators (1877), arguably misconstrued Matthew Hale’s treatise De Jure Maris about the nature of monopolies, a point the redoubtable Justice Stephen Fields—a firm natural law man—argued in his dissent that relied on first principles.

　　By degrees, it appears that originalism at the Supreme Court is slowly reviving key aspects of the natural law tradition found in what Jefferson described as “the elementary books of public right.” But it is being done in an indirect or circuitous manner, conspicuously avoiding direct mention of natural law, perhaps because the very idea of human nature itself has become so controversial in our wider culture. The originalist revolution will remain incomplete as long as this reticence persists, even while classic treatises persist, too. Thus originalists of whatever variety should hold off on declaring victory until this encouraging trend fully breaks out of its self-imposed box.