Joe Biden’s nomination of Ketanji Brown Jackson has renewed debates over the qualifications of Supreme Court justices. The timing could not be better for The Credentialed Court, by University of Tennessee law professor Benjamin Barton. Jackson may be hailed as an avatar of diversity as the first African-American woman nominated to the Court, but by Barton’s standards, her path from Harvard to a Supreme Court clerkship and a D.C. federal judgeship represents instead the diminishing di­versity of professional and life experience on the Court.

In Barton’s telling, “we have confused prestige with useful experience” and prioritized academic climbers over men and women with what Aristotle called phronesis, or practical wisdom — common sense.

This, he contends, departs from how Supreme Court justices were selected before the 1970s. Barton argues that we should learn from the wisdom of the Founding Fathers in choosing practicing lawyers of distinction, politicians, military veterans, and entrepreneurs rather than stocking the Court with specialists in “technical legal excellence.” Even readers skeptical of Barton’s arguments will find an entertaining, thought-provoking critique of the modern Court.

The Court is dominated by justices raised and schooled in the Boston–D.C. Acela corridor and educated at Harvard, Yale, and Princeton. Neil Gorsuch and Brett Kavanaugh went to the same high school and clerked together on the Court. Barton notes that even such opposites as Samuel Alito and Sonia Sotomayor have remarkably similar career paths. Donald Trump, who might have been expected to break the elite mold, instead scorned one candidate who merely attended Mich­i­gan Law School.

The Court once included statesmen such as John Jay, William Howard Taft, and Charles Evans Hughes. When Sandra Day O’Connor retired in 2006, the Court for the first time had no justices who had been elected to political office. Modern justices are at an all-time low in military and business experience.

The book is most entertaining in its vignettes from the lives of the justices. Byron White was a sports hero who wrote the Navy report on the sinking of John F. Kennedy’s PT-109. William Cushing was an undistinguished legal mind, but he kept the Massachusetts courts open while the Revolutionary War raged around him. Barton makes a vigorous case for why we should revere the pre-Court careers of John Marshall, Oliver Wendell Holmes, Louis Brandeis, Ben­ja­min Car­dozo, Thurgood Marshall, Ruth Bader Ginsburg, and more-forgotten figures such as Joseph Bradley.

Barton marshals data to show that the Court was once filled with men who made a broad and vivid mark on the world before joining its bench but is now the rarefied province of federal appellate judges and academics. The current Court averages an all-time low of 4.4 years of experience in the private practice of law, compared with more than 20 years as recently as the mid 1980s. Stephen Breyer was the first justice with no experience in private practice. Even recent nominees who spent years in practice rarely distinguished themselves. By contrast, Barton’s thumbnail biographies of George Washington’s ten nominees show that most were considered the leading lawyers in their states.

They were also generalist solo prac­titioners. Barton contends that generalists adapt better to new challenges. The Court handles an array of new and un­familiar problems and diverse areas of the law. Barton argues that counseling clients, interacting with juries and witnesses, and even losing cases are formative practical experiences the current Court lacks.

Barton is right that justices with more practical experience are less likely to write unnecessarily complex rules and discourses on theory and more apt to craft clear, simple tests that lawyers and trial judges can apply in practice. But Barton chooses a bad example, complaining about the Court’s recent decisions tightening the pleading rules for civil suits. That long-overdue move is a godsend to clients and judges who wish to avoid lengthy, costly discovery in meritless lawsuits.

How did we get here? The practice of law has changed: In 1872, there were only 14 firms in the whole country with more than three lawyers. Early justices were not federal appellate judges: Be­fore 1869, there were no federal appeals courts below the Supreme Court. Law­yers used to be trained as apprentices; Robert Jackson, appointed in 1941, was the last justice without a law degree. Supreme Court clerkships were introduced in 1882, and from the outset they entrenched the Harvard-grads-working-for-Harvard-grads pipeline.

Barton correctly identifies the judicial-confirmation wars that began with Earl Warren’s retirement in 1968 and accelerated after the Robert Bork hearings in 1987 as a crucial turning point in two ways. One, presidents facing ideological confirmation fights in the Senate tried to take qualifications off the table by choosing nominees with stellar academic résumés and elite experience that would appeal to gatekeepers such as the American Bar Association. Two, the back­lash to the Warren and Burger Courts made Republicans leery of nom­inees who drifted on the bench, so conservatives demanded judicial and academic records showing a consistent, rigorous approach.

A key moment came in 1970, when Richard Nixon was on his second effort to fill the vacancy from Abe Fortas’s resignation. His nominee, G. Harrold Carswell, was criticized for having a mediocre record; Republican senator Roman Hruska responded, “Even if he were mediocre, there are a lot of me­di­ocre judges and people and lawyers. They are entitled to a little represen­tation, aren’t they? We can’t have all Brandeises and Frankfurters and Car­dozos.” The remark sank Carswell.

Barton uses Brown v. Board of Education to echo Hruska. Franklin D. Roosevelt stocked the Court with law professors, and they fought like cats in a sack. Only 19 percent of the Court’s decisions were unanimous in 1951–52, even with nine Democratic appointees. As Barton notes, “anyone who knows a superstar law faculty will find these disputes, even among intellectual and political allies, unsurprising to the point of inevitability.” He compares this to today’s profusion of concurring opinions and splintered majorities.

Brown was on track to be a bitter, fractured decision until Chief Justice Fred Vinson died and Earl Warren was ap­pointed, bringing his formidable political skills to ensuring a unanimous opinion that spoke to popular opinion, even at the cost of intellectual rigor or doctrinal clarity. But this is a bit of a just-so story: Vinson was also a politician. Brown still provoked political backlash and decades of litigation. Its “all deliberate speed” formulation has been much criticized, and its hazy methodology has sown confusion in harder cases. So have many other Warren Court decisions.

Barton likewise lauds the high-handed prose of John Marshall, which was “praise­worthy precisely because of its rhetorical flourishes and appeals to logic rather than to a more technical legal approach.” By contrast, Barton is skeptical of theory, suggesting that “‘neutral principles of constitutional law’ — or, really, any other technical legal conception of the Court’s job — do not, in fact, offer much useful constraint on the Court.”

This is where conservative readers are apt to balk. Barton’s approach, while ideologically agnostic, runs the risk in practice of stripping the people of a crucial defense against judicial usurpation. Originalism and textualism aim to wield historical rigor to help constrain judges to follow rules written by the people’s representatives. Decisions long on pronouncement and short on sources are more apt to stray from constitutional and statutory designs. Requiring nominees to show fidelity to constitutional legitimacy is indispensable. George Wash­ington didn’t care about judicial paper trails, but he concentrated his appointments on men who had written the Constitution and advocated its ratifi­cation. Jay was one of the authors of the Federalist Papers. Oliver Ellsworth helped forge the Connecticut Com­pro­mise and draft Article III and the Judiciary Act.

Some of Barton’s prescriptions are similarly dubious. He cites Joseph Brad­ley’s experience as a railroad lawyer and mathematician as an example of why we should “make the justices weird again,” but is that desirable? Bradley, a Ulysses S. Grant appointee, wrote privately on the original meaning of the 14th Amend­ment but strayed from it publicly in United States v. Cruikshank and the Civil Rights Cases, betraying Republican Recon­struc­tion.

Barton wants the justices to go back to riding circuit to interact with regular Americans and routine cases, but that seems redundant with selecting justices who have prior practical experience. In today’s world, it might also pose a security risk. Even in Washington’s time, one of his appointees, James Wilson (a key father of the Constitution), was clapped into debtors’ prison while riding circuit.

That is not to say that originalists have nothing to learn from Barton’s critique. Antonin Scalia, originalism’s prophet, often grounded his opinions in a practical understanding of how the structure of government works, what makes the Court’s decisions legitimate to the common man, and how bright-line rules are more administrable. Clarence Thomas loves touring the nation in his RV. Originalist jurisprudence should not be sterile or purely mechanical. Its understanding will be richer, and its rules more durable, if informed by experience. The Constitution was written by and for worldly men. It should be read that way.