When the Supreme Court begins its new term Monday, the death penalty will dominate the justices’ attention, as four separate capital punishment cases are on the docket. In a new interview with MSNBC, Justice Stephen Breyer explained why he thinks the Court should consider banning the practice.

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“Sometimes it’s the wrong person,” he said, citing instances of wrongful convictions in capital cases. “Often it’s very arbitrary as to who gets executed – it’s not the worst of the worst, very often,” Breyer said.

“The risk of arbitrariness is so great,” he continued, “and all that put together convinced me that there is a good case to be made under the Constitutional provision, ‘Is it a cruel and unusual punishment’– those are the things that are relevant – that this court should hear the case.”

Breyer was reflecting on the arguments from his dissent this summer, when the court rejected a challenge to specific drugs Oklahoma planned to use to execute a convicted murderer, Richard Glossip. That ruling cleared a path for the execution, but on Friday, a lower court halted it indefinitely.

WATCH: Shocking stay of execution in Oklahoma

The high court’s new cases only cover limited aspects of capital punishment – sentencing and jury instructions – but even death penalty supporters see a larger tide turning.

“Sometimes it’s the wrong person. Often it’s very arbitrary as to who gets executed — it’s not the worst of the worst, very often.” Justice Stephen Breyer Justice Antonin Scalia said this month at Rhodes College in Memphis, “and there is now a fourth — Justice Breyer has announced that he thinks the death penalty is unconstitutional.” Scalia made headlines by noting he “wouldn’t be surprised” if the court ended capital punishment.

Breyer declined to address Scalia’s remarks, saying, “I won’t go beyond what I said – what I said was, ‘We should hear it.’ And that means you get arguments from both sides.”

Breyer spoke to MSNBC about a range of legal issues from the Lawyers’ Lounge at the Supreme Court, part of a series of interviews he granted to discuss his new book, “The Court and the World.”

“The Court and the World”

The book argues that while American courts traditionally focus on domestic precedent, they now increasingly face a duty to reckon with a globalized world. The thesis may strike lay audiences as uncontentious, but it actually counters a growing effort to narrow judicial review.

The book cites, for example, a 2004 House bill that sought to prevent judges from even examining material from “foreign institutions.” A third of the House Republicans caucus backed that legislation at the time.

“This world that we’re in has increased complexity because security matters that threaten us are taking place abroad, because environmental matters that concern us involve more than our country.” Justice Stephen Breyer

His book strikes a tone of respectful, reasoned disappointment with the kind of political nativism that increasingly spills into legal circles. This includes the arguably legitimate concerns that he addresses, such as the objections to applying “foreign law,” to unconstitutional and fairly appalling positions, such as calls to keep Muslims from serving as judges. (By focusing his analysis on the practice of judging, Breyer largely avoids an analysis of the sentiments animating these positions.)

“This world that we’re in has increased complexity because security matters that threaten us are taking place abroad, because environmental matters that concern us involve more than our country,” Breyer told MSNBC, “because trade, which at least has the possibility of enriching us, can sometimes do so when it takes place in more than one nation.”

Looking back

Asked about his most significant opinions for the court, Breyer volunteered an international copyright case, which illustrated themes from his book, and his thorough dissent to a controversial 2007 ruling, when a conservative majority halted school integration programs under Brown v. Board of Education.

“I went in considerable length to say that it was lawful sometimes to take race into account, for reasons of positive discrimination or affirmative action, in deciding who will go to what secondary school,” Breyer recalled.

“I learned this from Arthur Goldberg, for whom I was a law clerk. He said, ‘You decide the case. Maybe you won it – maybe you lost it. And now what you do is it’s on to the next case.’ And that is a much better attitude.” Justice Stephen Breyer

He said he does not dwell, however, on past opinions.

“I felt strongly that education is such a huge problem, and part of it is tied up with race,” he noted, while emphasizing an approach he learned from Justice Arthur Goldberg.

“Do I go back and look back in an opinion I wrote and try to measure it and say, ‘Was I right? Hah hah hah’? No, I don’t,” he said. “I learned this from Arthur Goldberg, for whom I was a law clerk. He said, ‘You decide the case. Maybe you won it – maybe you lost it. And now what you do is it’s on to the next case.’ And that is a much better attitude.”

So while lawyers and scholars carefully parse judge’s opinions, Breyer says he does not re-read his work.

“When you’ve written the book, you’ve done your part,” he said. “It is then up to other people to decide whether they want to read it and whether they’ll learn something from it.”

While Breyer spoke about cases touching on many major issues, including Guantanamo, foreign treaties and domestic surveillance, he declined to discuss the dissent he joined in Citizens United, which held corporations have a First Amendment right to spend unlimited sums on campaigns.

“That’s a very important issue,” he said, adding, “it’s complicated and takes a significant amount of time to explain, and so I would rather not explain it on television, because it is so controversial.” Hillary Clinton and Bernie Sanders, while campaigning for president, said they would only nominate judges who will overturn the ruling.

Diversity on the bench

Breyer also welcomed increasing diversity in judicial appointments.

“I’m not part of the appointing process,” he said, “I am part of the appointed. I was appointed – not appointing.” Asking a judge about appointments, he added, is like asking “for the recipe for Chicken à la King from the point of view of the chicken.”

He went on to praise the role of different experiences on the bench.

“Law is not a computer, and the answer doesn’t spew out of a computer,” he said. “And the precedents in this court, it’s open, you know, almost always. If they dictated a result, why is it in the court? So it’s important that decisions that affect people – and they do affect people – that when they’re made, those who make them understand or try to understand or do their best to understand the nature of lives that might be very different from their own. And that’s why a diversity of experience is – other things being equal – helpful.”

His spare time

When he isn’t working, Breyer likes to write and read, typically ordering books from Amazon.com.

“I’ve always wanted to read more Mark Twain,” he said, and he recommended the work of Willa Cather, an author from Nebraska who depicted frontier life in the early 20th Century.

At 77, Breyer has served on the Court for 21 years. He shows few signs of slowing down. Asked how he will know when it is time to retire, he said it’s “a good question,” and he will know.

“So far, I seem to be able to do the job,” he said. “And there will happen be some indication, or I’ll think about it, but I haven’t thought it through enough yet to be able to give you much guidance on when I’ll retire.”

A philosophical difference

Finally, reflecting on public views of the court, Breyer objected to the notion that the justices are “junior league politicians.”

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The court’s approach differs, Breyer said, from the fixation on popularity that he saw working in the political branches. (He served as counsel to a Senate Committee and briefly on the staff of the Warren Commission.) “That level of politics, I don’t see it here,” he stressed. “And even if you say Bush v. Gore, I’d say, I think I could convince you in an hour that maybe not even that one was political, in that sense.”

Instead, Breyer suggested the justices differ philosophically, and he has come to view that more favorably over time.

“I used to think,” he said, “everyone should agree with me – and why don’t they? And I’ve changed in that respect,” he explained. “I think I understand better, it’s not a bad thing, in this country, to have people of very different philosophical views on the court. Why? We’re a big country,” he said. “It’s not such a terrible thing to have a court whose members, coming from different backgrounds,” have come to embrace a more than one “philosophy of what law is about.”