The Supreme Court has rejected an equality-based constitutional challenge to a law requiring couples to adopt either the husband’s or the wife’s surname. The decision is fascinating in its own right, reflecting the contemporary moment for feminism in Japan. It also raises a much broader question: How much should a constitution reflect the distinctive values of the society in which it operates, and how much should it express fundamental rights recognized almost universally?

The decision of Japan’s highest court exemplifies this question in a very concrete way. The Civil Code, enacted in 1896, during the Meiji Era of Westernizing reforms, required that married women adopt their husbands’ family names. A 1947 revision created Article 750 of the code, which says the couple must adopt one family name, which can be that of the husband or the wife.

The provision had an intriguing history. Until 1870, commoners in Japan generally didn’t use surnames. In 1876, the reformers decided that women should keep their own names upon marriage. The 1896 law reversed this rule, bringing Japan into closer conformity with Western practice of the time.

Today, 96 percent of couples choose the husband’s name. This has led to challenges from feminists and pressure from the United Nations Committee on the Elimination of Discrimination Against Women, which considers the provision sexist.

The Supreme Court’s decision relied in part on the formal equality of the provision, which it said was sufficient to satisfy the anti-discrimination provision of the Constitution. But the real work of the decision almost certainly lies in the court’s pronouncements about the distinctive aspects of Japanese society. The opinion for the court said that sharing the family name is “deeply rooted in our society” and “enables people to identify themselves as part of a family in the eyes of others.”

In the run-up to the decision, supporters of the law had said that changing it would reflect “the spread of extreme individualism … family with the surname has a sense of unity.” This, too, reflected distinctly Japanese concerns with the tension between individualism and family. Polls suggest that the public is roughly evenly divided on the issue, but the Liberal Democratic Party, which tends to be conservative in social matters, has declined to change the law.

The case therefore pitted one version of Japanese values against a more universal, international conception of women’s equality. What should a court do when faced with such a tension? The issue arises frequently in the Islamic world, where traditional religious practices may be in tension with contemporary equality norms.

But the tension between local tradition and international norms also comes up in the United States.

The death penalty has a long and well-established track record in the U.S. Historically, it was not seen as cruel and unusual punishment, except for four years between 1972 and 1976 when the U.S. Supreme Court said that it was cruel and unusual as applied.

But today, almost all countries in the world (140 as of the last count) consider the death penalty to violate universal human rights norms — a reality which surely influences liberal justices like Stephen Breyer and Ruth Bader Ginsburg, who called in June for an end to the death penalty on constitutional grounds.

Another example is gun rights. Supporters think of firearms as deeply rooted in American tradition. To them, the Second Amendment stands for self-protection alongside hunting — even though the amendment was originally designed to ensure the existence of organized state militias. This particular American tradition of gun ownership is in tension with international — especially Western European —norms of strong restrictions on gun ownership.

The American tradition of free speech, which we think of as grounded in the First Amendment, also differs sharply from universal conceptions of equality and the elimination of racism and sexism that are embodied in international treaties. The U.S. is one of only a handful of countries whose constitution has been interpreted not to allow bans on racist hate speech or on speech that demeans the equality of women.

These examples show how difficult it is to reach a decision when the local conception of constitutional rights contradicts the international view.

Indeed, this tension is at the very heart of constitutionalism itself. If “we the people” ordain the constitution, it should presumably reflect our distinctive ideals and values. But if the rights we’re protecting are the “self-evident” and “inalienable” rights mentioned in the Declaration of Independence, then they shouldn’t be affected by our local values. They should be true always and everywhere.

It’s tempting to say that some rights are local and others are universal. But in the real world, that theoretical distinction is almost impossible to apply.

The bottom line is that when we’re arguing about the nature of rights, there’s no definitive answer that can be gleaned from looking to universal practice. You can’t find moral laws in the fundamental structure of the universe. You have to convince other people that the rights you consider universal are worth protecting.

Meanwhile, our conception of local values depends on many things, including invented traditions like married names in Japan or (according to some historians) individualized gun ownership in America. These values, too, come into existence through argument, and can change over time.

Constitutionalism is a name we give to the practice of arguing about rights through the “meaning” of constitutional documents. It doesn’t have absolute rules, and it’s far from a perfect social practice. But it beats playing out the same arguments using violence. And when it works, it tends to produce social consensus around value choices. That’s why it’s worth preserving — and worth understanding.

Noah Feldman, a Bloomberg View columnist, is a professor of law at Harvard University.

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.