"I was in dissent quite a lot and I wasn't happy," Breyer said at the American Bar Association's annual meeting.
Breyer was one of four liberal justices who dissented in cases involving abortion rights, school integration and pay discrimination. In the school case, in which the court struck down student assignment plans in Louisville, Ky., and Seattle, his frustration bubbled over in a lengthy dissent that was twice as long as any he had written in his 13 years on the court.
Yet with the passage of some time, Breyer said the court's term underscored his faith in the rule of law.
"When I look at it objectively, I think how I wish I'd won, but I also think, not a bad system," Breyer said.
"I'm not going to be in the majority all the time. How I wish I were, but that's the system. That's called the rule of law," he said.
Earlier, addressing another ABA audience, Breyer said the major division in the world is between people committed to resolving disputes through a system of laws and those who are not.
Breyer praised the group's volunteer effort to train lawyers and judges around the world to adhere to the rule of law, despite changing political environments.
After the Sept. 11, 2001, attacks, Breyer said: "I began to see that the true division of importance in the world is not between different countries. The important division is between those who are committed to reason, to working out things, to understanding other people, to peaceful resolution of their differences ... and those who don't think that."
He said the nine justices on the court were unanimous in that belief, even as they disagree vigorously over the issues that come before them.
At the time of the attacks, Breyer said, he was in India with Justice Sandra Day O'Connor to meet with judges and lawyers there. Even as American diplomats wanted to send the justices home immediately, they insisted on going ahead with meetings to demonstrate the strength of the U.S. system, he said.
Since 1990, the ABA has sent lawyers to emerging democracies to promote anti-corruption laws, criminal law reform and formation of an apolitical corps of judges.