Supreme Court Justice Anthony Kennedy wasn’t out to make news when he addressed the annual conference of the Ninth U.S. Circuit Court of Appeals and devoted most of his 50-minute speech to the Magna Carta, which turns 800 years old in 2015. But Kennedy did let on that he doesn’t belong to the school of Constitution-worshipers who base their legal doctrines on what they glean to be the original, literal meaning of every word and phrase in the nation’s founding document.

“The Constitution of the United States is a flawed document,” Kennedy said at Thursday’s windup conference session in Monterey. By “thinly veiled language,” he said, it “basically reaffirmed the legality of slavery,” referring to provisions that allowed the slave trade to continue at least until 1808 and defined each slave as three-fifths of a person when deciding how many congressional delegates to assign to each state.

The 600,000 who died in the Civil War, Kennedy said, were “one of the things it cost for having a Constitution that was flawed.”

At the same time, he said, the drafters of the Constitution had the insight to declare principles, like due process of law, that could be interpreted anew by future generations — a sacrilege to literalists like Justice Antonin Scalia, who contends the court is strictly bound by what he deems to be the original intent and meaning of the document.

“The framers were wise enough to know that they could not foresee the injustices” of the future, Kennedy said, “so they used general language.”

He then proceeded to a brief, historical defense of Scalia’s 2008 ruling that overturned a ban on handguns in Washington, D.C., and declared that the Second Amendment protects an individual’s right to possess at least certain firearms at home.

The Second Amendment, ratified along with the rest of the Bill of Rights in 1791, had been interpreted by the court as late as 1939 to protect only the right to bear arms in a “well-regulated militia.” But Kennedy observed that constitutional understanding can change over time — for example, the 1896 ruling in Plessy vs. Ferguson, which upheld segregation in public transportation as “separate but equal,” wasn’t overturned by the court until the 1954 Brown vs. Board of Education decision, which outlawed school segregation and mandated equal treatment of the races under the Fourteenth Amendment.

By the same token, he said, some critics have claimed that the decades, or the centuries, it took the court to declare an individual right to keep and bear arms “means that it doesn’t exist.”

“I’m not so sure,” said Kennedy, who was part of Scalia’s 5-4 majority in the 2008 ruling.