A celebrity, said historian Daniel Boorstin, is someone known for his or her well-knownness. David H. Souter, who died on May 8 at 85, was the anti-celebrity. He came to Washington to serve almost 20 years on the Supreme Court (1990-2009), then returned, at 69, to New Hampshire, trailing clouds of anonymity.

He is remembered in Washington as odd: enjoying solitude, indifferent to publicity — what was wrong with him? Conservatives remember him as a disappointment. Nominated by President George H.W. Bush to replace liberal Justice William J. Brennan Jr., Souter was supposed to cement a conservative court majority.

He did not. His legacy should, however, include a thoughtful hesitancy when flinging about the adjectives “liberal” and “conservative” regarding justices.

He was too deferential (and illiberal) in approving federal campaign regulations by which government rations political speech about the government’s composition. He was too permissive (and illiberal) in approving local governments’ coercive use of eminent domain to transfer individuals’ private property to facilitate private commercial interests. If, however, conservative critics fault him for joining the court’s majority in invalidating anti-sodomy laws, does conservatism stand for conserving the majority’s right to criminalize deviations from its cultural preferences, and perhaps diminishing equal protection of the laws?

Justices should be judged not by results — the social policy consequences of particular decisions — but by how the justices exemplify the subtle nuances of judicial reasoning. Consider Souter’s 2010 Harvard commencement address about judging, illustrated by the 1954 Brown v. Board of Education decision overturning the “separate but equal” justification for school segregation, and the 1971 Pentagon Papers case.

In 1896, when the court affirmed separate but equal segregated railroad cars, the majority regarded the law as race-neutral. Fifty-eight years later, the Constitution’s language had not changed. What had?

The 1896 justices, Souter said, remembered law-sanctioned slavery. To them, “the formal equality” of identical railroad cars “meant progress.” The 1954 justices, “without the revolting background of slavery” to make it look acceptable, saw a meaning in school segregation that the 1896 justices did not. The judicial perception of meaning, Souter said, “comes from the capacity to see what is not in some simple, objective sense there on the printed page” of the Constitution. (As is, for example, the constitutional fact that a president must be at least 35 years old.) Souter said the 1954 justices were guilty of impermissible “activism” only if you believe the constitutionally determinative facts always “lie there waiting for an objective judge to view them.”

In 1971, the government tried to prevent publication (by the New York Times and The Washington Post) of classified documents the publication of which would, the government argued, threaten national security, jeopardize attempts to negotiate peace and prevent all foreign governments from trusting ours. The newspapers argued that the First Amendment’s finality settled the issue: No law shall abridge press freedom.

The government lost the case, but the court accepted its basic argument, which was: When construing a portion of the Constitution, the totality of the document can be germane. It guarantees press freedom — but also grants the government the authority, responsibility and appropriate power to provide for the nation’s security and enable the president to conduct foreign and military policy.

The Constitution, Souter said, serves Americans’ desire for two excellent things, security and liberty, that are not always clearly and cleanly compatible. In this case, Souter said, these “paired desires” clashed, and the court had to decide which had “the better claim, right here, right now.”

The court did not say the First Amendment’s facially absolute “no law” permitted no exceptions. It did say that there can be circumstances in which exigencies justify government restraint of publications. The court said only that in this case the government failed to demonstrate a sufficient exigency.

Souter asked his 2010 listeners: Did the 1971 court abuse its power? No, he said, a choice had to be made, the Constitution did not make it, so the court had to do it. “So much,” he said, “for the notion that all of constitutional law lies there in the Constitution waiting for a judge to read it fairly.”

Constitutional law is substantially judge-made rules (what is “equal protection” of the laws? a “reasonable” search? a “cruel and unusual” punishment?). Rules that, Souter argued, judges cannot avoid making. These “turn into” rules as, over time, the court copes with cases.

No single theory of proper constitutional interpretation (originalism, textualism, etc.) can satisfy the hunger for simplicity, clarity and finality. Each requires Souter’s well-known trait: judiciousness.

George Will writes a column for the Washington Post.