Justice Stephen G. Breyer said the other night that there are two preconceived notions about the Supreme Court that he faces each time he speaks at a university or law school.

The first is that he and his fellow justices take cases just because they think the issues would be interesting.

And the second is that the outcome is pre-ordained because the nine are not so much objective interpreters of the law as, in Breyer’s words, “junior league politicians.”

The first is fairly easy to refute by anyone familiar with the court’s day-to-day docket. This week, for instance, features two patent cases. While every patent case is a blockbuster to patent lawyers, lines are not yet forming outside the marble palace because Wednesday’s argument is over “divided infringement.”

The justice’s second point is a lot tougher, though Breyer told Jeffrey Rosen of the National Constitution Center Thursday night that “I think if I had the time, I could persuade you.”

Last week at the court might be a place Breyer would start.

If there is anything that a justice likes more than being in the majority, it is being in a majority that defies the court’s orthodoxy of liberals in one place, conservatives in another and Justice Anthony M. Kennedy occasionally leaving the right to give a victory to the left.

All four of the court’s decisions last week upset that pattern.

Conservative ideological soulmates Clarence Thomas and Antonin Scalia were on opposite sides of a ruling that an anonymous tip called into 911 was a good enough reason for cops to stop a driver for alleged drunken driving.

Thomas wrote the majority opinion for the court’s usual conservatives — Chief Justice John G. Roberts Jr. and Justices Kennedy and Samuel A. Alito Jr. — plus the usually liberal Breyer.

Scalia rallied the court’s other consistent liberals — Justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan — with a thunderous dissent.

The majority, Scalia wrote, had armed law enforcement with a “freedom-destroying” power that curtails an individual’s right to “come and go as we please without police interference.”

In a second case, Kagan joined the conservatives in turning down a Kentucky death-row inmate’s claim that his sentence for a 1997 murder deserved additional review.

The court split three ways in trying to decipher a fuzzy law Congress passed ordering restitution to child pornography victims from those who are convicted of possessing their images.

The majority said lower court judges should “do their best” to align the amount a defendant owes with the harm his specific actions caused the victim. The dissenters — Roberts, Scalia and Thomas for one reason, Sotomayor for a different one — said the law made this impossible and urged Congress to go back to the drawing board.

And the court’s major ruling last week — upholding Michigan’s constitutional ban on considering race in university admissions decisions — came from a similarly mixed majority.

The decision is rightly seen as a continuation of the conservative Roberts Court’s skepticism, if not outright hostility, to governmental use of racial classifications. But despite Sotomayor’s searing dissent accusing the majority of trying to “wish away” racial inequality, she failed to get Breyer’s vote.

(Sotomayor was joined by Ginsburg; Kagan recused herself from the case presumably because she had worked on it while serving as solicitor general in the Obama administration.)

Breyer believes in the court’s precedents that say it is constitutional to consider race in limited circumstances; he wrote a blistering dissent when conservatives on the court in 2007 threw out decisions by elected officials in Seattle and Louisville that considered race in making school assignments.

But in his somewhat overlooked opinion last week concurring with the majority, Breyer said the court must defer when voters decide otherwise.

The Constitution, Breyer wrote, “favors decisionmaking though the democratic process. Just as this principle strongly supports the right of the people, or their elected representatives, to adopt race-conscious policies for reasons of inclusion, so must it give them the right to vote not to do so.”

Another case put the court into the spotlight last week. It was the fight over Internet startup Aereo and the networks that accuse it of appropriating their content without compensation.

It brought a world of condescension from technology writers and bloggers about the grandpas and grandma on the high court deciding the future of television. The headline on washingtonpost.com’s The Switch blog was “The Aereo case is being decided by people who call iCloud ‘the iCloud.’ Yes, really.”

But both the company and the networks asked the court to settle the issue, and the court is trying to apply a law written in 1976 to the latest technical innovations. Even the articles criticizing the justices — who often sound technology-challenged at oral arguments — acknowledged that they don’t need to be able to write code in order to interpret copyright law.

The Aereo argument didn’t present the partisan implications other cases bring. And Breyer is right, of course, that the justices are not politicians.

But they were chosen by politicians and confirmed by politicians; there is no overlap on the lists of potential Supreme Court justices prepared for Democratic and Republican presidents.

It has worked out well recently. Former President George W. Bush would have few quarrels with the decisions of the men he appointed to the court, Roberts and Alito. And President Obama could hardly be disappointed with the women he chose, Sotomayor and Kagan.

And by the time the term ends in June, there will be 5 to 4 decisions that precisely confirm the court’s ideological divide.

Rosen, who is also a law professor at George Washington University, told Breyer that he instructs his students to employ the tools Breyer suggested for analyzing questions of law: “text, history, tradition, precedent, purposes, consequences.”

If they believe it’s all about politics, Rosen tells his students, they will “miss everything that’s beautiful about constitutional law.”

Guess what? Rosen told Breyer.

“They don’t believe me. They think it’s all politics.”