Ronald Dworkin, who has died at age 81, was the leading liberal constitutional theorist of his era. But that is not why his ideas are so important nor is it why history will remember him.

Instead, Dworkin’s essential contribution applies equally to American liberal and conservative legal thought: Constitutional decision-making rests on a bedrock of the judges’ political morality -- and so do the rights we enjoy.

If this thought seems obvious today, Dworkin had much to do with making it so. Until he started writing in the 1960s, the dominant trend in legal theory in the English-speaking world was to the contrary. Ever since Jeremy Bentham had declared that natural law was “nonsense on stilts,” the leading British and American legal philosophers had insisted on a strict distinction between law and morals.

The apotheosis of this view could be found in the writings of Justice Oliver Wendell Holmes, who believed that law had nothing to do with right and wrong; it was just a prediction of what courts would do. In fact, Holmes said, if you wanted to know the law, you should to take the perspective of a bad man who hoped to avoid punishment -- whatever he could get away with was the law. This view fit hand in glove with Holmes’ nihilistic judicial restraint. He thought that the courts shouldn’t invoke morals to stop legislatures from adopting laws, whether the laws embodied socialism or eugenics.

Interpreting Words

To Dworkin, who came of age in the era of Brown v. Board of Education, the idea of separating law from morals made no sense. Part of the judge’s job is to apply the Constitution. The Constitution, for its part, speaks in vague terms, using words like “equal protection,” “due process” and even “the right to bear arms.” None of these terms could be understood without interpretation. And that interpretation, Dworkin argued, necessarily involved moral judgments about what would make the law the best law that it could be.

Dworkin’s theory of law as interpretation is just as relevant for conservatives as liberals. What is the best way to interpret “the right to bear arms”? It depends on your moral vision for the country. If you see guns as crucial to self-defense and a secure, robust citizenry, then you should interpret the Second Amendment broadly to protect assault weapons. If your moral vision is one that rejects a self-armed, self-protecting populace, then you should interpret the right narrowly.

To Justice Antonin Scalia, the leading contemporary judicial exponent of law independent of morality, Dworkin’s approach was heresy. To Scalia, the judge’s job is simply to say what the law is, never what it should be. Interpretation, while inevitable, should be mechanical -- and above all, it should exclude moral beliefs.

In response to Scalia, Dworkin had a devastating riposte. How, he asked, did Scalia know that the judge’s job was simply to apply the law? The Constitution never expressly says so, and in fact never specifies how it should be interpreted. The answer, Dworkin explained, was that Scalia had to rely on his own theory of the best moral vision for the country. In Scalia’s political morality, judges should exercise restraint. But that belief itself was a product of interpretation and moral judgment -- and logically couldn’t be otherwise. Scalia’s “love affair with textual fidelity,” as Dworkin put it, was therefore proof that he was interpreting the Constitution in the light of his moral judgment.

Continued Insistence

Needless to say, Dworkin’s argument hasn’t stopped Scalia from continuing to insist that his jurisprudence leaves morals to one side. But it is increasingly difficult to find anyone who takes that insistence seriously. Anyone who even vaguely remembers the Bush v. Gore decision understands that conservatives and liberals interpret the Constitution in keeping with their moral preferences.

Yet having accepted this reality as unavoidable, Dworkin never succumbed to cynicism about constitutional interpretation -- and therein lies his historical importance. Many people, observing the justices using the language of the law to debate their moral visions, conclude that something has gone terribly wrong and that the judges are hiding something from the public.

Dworkin looked at judges’ heated discussions and saw the exact opposite: conscientious decision makers trying to find the truth using the proper moral tools. It would be preposterous, he believed, to think that the judges somehow didn’t know their job when they relied on morality to understand the meaning of the Constitution. Indeed, any theory that didn’t treat the judges’ moral debates as part of the legal process wasn’t describing law at all.

The polar opposite of a relativist, Dworkin firmly believed that there were right and true answers to even the hardest legal questions. The way to find them was through careful and correct moral analysis and judgment. Although his own politically liberal views led him to conclude almost all the time that the liberal view of the Constitution was the true one, that useful coincidence shouldn’t cast any doubt on the value of his overall constitutional approach.

Above all, Ronald Dworkin looked on our vigorous constitutional debates and saw in them something noble, worthwhile and meaningful. He insisted that arguing about what the Constitution means in the light of our values is the very essence of our constitutional genius. Seeing this clearly, and defending it confidently, was his.

(Noah Feldman, a law professor at Harvard University and the author of “Scorpions: The Battles and Triumphs of FDR’s Great Supreme Court Justices,” is a Bloomberg View columnist. The opinions expressed are his own.)

To contact the writer of this article: Noah Feldman at noah_feldman@harvard.edu.

To contact the editor responsible for this article: Tobin Harshaw at tharshaw@bloomberg.net.