In refusing to strike down a race-conscious admissions plan at the University of Texas at Austin on Thursday, the Supreme Court did more than uphold an affirmative action program. Just as important, it struck a much-needed blow for judicial modesty.

The justices showed an awareness that others might know better than they do. We could use a lot more of that.

The crucial part of Justice Anthony Kennedy’s majority opinion came toward the end. “Considerable deference is owed to a university,” he wrote, “in defining those intangible characteristics, like student body diversity, that are central to its identity and educational mission.”

Kennedy added that public universities can operate as “laboratories for experimentation,” and have “a special opportunity to learn and to teach.” Pointing to the centrality of facts, he emphasized that they have “valuable data about the manner in which different approaches to admissions may foster diversity or instead dilute it.”

Here’s the background. Under state law, the university must offer admission to any students who graduate from a Texas high school in the top 10 percent of their class — a race-neutral provision. But applicants outside that pool are considered by reference to a large numbers of factors. Race is one of them, but just one, and it is not used mechanically. A rejected white applicant, Abigail Fisher, argued that the university’s decision to consider race at all was unconstitutional.

In response, Kennedy’s majority opinion said that the university can take race into account if it is attempting in good faith to improve the educational process — for example, by promoting cross-racial understanding or by preparing students for an increasingly diverse workforce. Kennedy noted with approval that in designing its program, the university referred specifically to those goals; it also contended that racial diversity can improve the academic environment.

Fisher objected that because Texas law requires universities to admit students who fall within the top 10 percent, it already ensures racial diversity, and so there is no need for separate consideration of race. Kennedy answered that the university had carefully considered that very claim and concluded, on the basis of statistical evidence, that it was wrong just on the numbers — the 10 percent policy alone wasn’t enough.

Kennedy’s deference to the University of Texas won’t much move you if you are certain the U.S. Constitution flatly forbids consideration of race (as Justice Clarence Thomas is). And if you believe, with Justices Samuel Alito and John Roberts, that federal courts should assess affirmative action programs with intense skepticism and in the finest detail, deference will be equally unappealing.

On this count, the real separation between the justices’ views is best signaled by the fact that Kennedy’s majority opinion is just 20 pages, while Alito’s dissent is a whopping 51, largely dedicated to flyspecking the university’s justifications for its program.

The majority had it right. Reasonable people differ about race-conscious admissions programs — whether they should exist at all and what form they should take. The numerous colleges and universities across the United States have to act in the face of radically different admissions pools and historical contexts, as well as challenging trade-offs and competing values. Each has a lot of local knowledge, above all of facts. And their judgments ought not be second-guessed by a small set of lawyer-judges in Washington.

There’s a broader lesson here. It’s often appealing to try to resolve difficult social problems by reference to some big, abstract principle. And some of the time that works. The ban on slavery, for instance, shouldn’t depend on context.

But too often, judges are tempted to invoke an abstraction, in the Constitution’s name, that is hopelessly ill-suited to the sheer diversity of situations to which it might be applied. The court’s brief and humble opinion, showing admirable respect for educators in Texas, properly resisted that temptation.

Cass R. Sunstein, the former administrator of the White House Office of Information and Regulatory Affairs, is the Robert Walmsley university professor at Harvard Law School and a Bloomberg View columnist. — Ed.