For Justice Antonin Scalia, cases before the U.S. Supreme Court involving the Bill of Rights are important, but they aren’t the ones “I live or die for.” That distinction, he said in a speech over the weekend, is reserved for cases that test the structure of the U.S. government, from separation of powers to federalism.

Even dictatorships can have a bill of rights written down, he said, but the structure of government is what ensures that laws are “not just words on paper.”

Scalia spoke November 17 at The Federalist Society’s annual convention in downtown Washington. He was there to promote his new book, Reading Law: The Interpretation of Legal Texts, but devoted much of the talk to answering questions on everything from his judicial philosophy to his taste in opera (“I shed a tear for Madame Butterfly every time I watch it,” he said of Giacomo Puccini’s opera.)

Reading Law, which Scalia co-wrote with Bryan Garner, explores the canons of interpretation that judges can rely on and delves into the principles of a judicial philosophy that Scalia adheres to, textualism. Asked whether Congress could legislate canons, Scalia said that while Congress “can say whatever it wants” in statutes, he didn’t think legislators could pass laws dictating how judges interpreted the law. “Congress has its job and we have ours,” he said. In a line that drew laughs from the packed ballroom, he added, “They can’t tell us to set aside rules of logic!”

Scalia took several jabs at what he saw as the alternatives to textualism. For example, he said that under “purposivism,” described in his new book as evaluating the purpose behind a law as opposed to sticking to the text, judges might interpret laws under concepts that are too broad, such as whether they “do good” or not. “If you play that game, you’re free to rewrite the law,” he said.

In defending originalism – a subset of textualism that focuses on the public meaning of a law or constitutional provision when it was adopted – Scalia said it wasn’t necessary for judges to be trained historians. Judges constantly rely on experts, he said, citing patent cases as an example. Lawyers rarely addressed historical perspectives when he first took the bench, he said, but they’ve increasingly done so as more judges have adopted an originalist approach. In reaching the court’s landmark Second Amendment decision in 2008 in District of Columbia v. Heller, for example, Scalia said the court got significant historical assistance in amicus briefs.

Originalism should apply even in cases dealing with modern technology, he said. In deciding what constitutes cruel and unusual punishment for the death penalty, for instance, he said he would consider whether modern procedures such as lethal injection are more cruel than the once-common practice of hanging. In his opinion, he said it was not.

Scalia weighed in on the state of legal education, saying that law schools should be better preparing students to read and interpret laws. “You pick up canons of interpretation haphazardly,” he said. The days of judges being tasked with creating new common law are mostly over, he said; the function of modern judges and lawyers is to determine the fairest reading of legal texts.

Different canons may contradict each another, Scalia said, but he warned against considering any one canon as absolute. “Canons are clues to the meaning of the text,” he said. The task for judges is to decide “which clues are the most persuasive.”