“We hold that the New York City Board of Health, in adopting the ‘Sugary Drinks Portion Cap Rule,’ exceeded the scope of its regulatory authority. By choosing among competing policy goals, without any legislative delegation or guidance, the Board engaged in law-making and thus infringed upon the legislative jurisdiction of the City Council of New York.”

* * *

Those are the words with which New York state’s highest court put paid Mayor Bloomberg’s ban on large sugary sodas. The ruling sustains Justice Milton Tingling’s ruling, which in March of last year found that the city’s Commissioner of Mental Hygiene, Thomas Farley, and the other members of the board of health had no basis whatsoever in the law or city charter to do what they had done. It gave a straightforward answer to Mr. Bloomberg, who had ridiculed Justice Tingling’s ruling, saying it was “clearly in error” and declaring, “we believe we will win on appeal.”

This is a teaching moment for all of New York. The American system — at the federal and state level — is a system of republican government. Republican not in the sense of Republican Party but in the sense of representative democracy in which elected officials are granted certain powers, the powers are enumerated, they are written down, they are separated among branches, and they are limited. The grants of power to the federal government are made in the Constitution, to the state government in the State Constitution, and to the city government in the State Constitution and the City Charter.

What is so wonderful about the decision of the Court of Appeals yesterday is the vindication it gives to a certain kind of judging. Justice Tingling went into his chambers and read every iteration of the New York City Charter back to the 1600s. What he discovered was startling. In granting powers to a Board of Health, the people were worried not about how fat we were or whether we, say, stayed out in the sun too long. They were worried about germs and communicable diseases. They did not mean to tell us how to balance the costs and benefits of our own diet.

And the people were most assuredly not intending to create a second legislature other than the City Council. The most reassuring thing about the sugary soda case is the bluntness with which the lower and higher courts rejected the astounding arrogance of Dr. Farley and the Board of Health and Mental Hygiene. The were claiming inherent law-making authority. They weren’t worried about health. They were grabbing power. The Court of Appeals saw through that plain as day. As did the labor and industry groups at whose expense Dr. Farley & Co. were acting.

Congratulations to them are in order. But with a cautionary note. But six of the Court of Appeals’ seven judges participated in the soda decision. Judge Rivera did not take part. Chief Judge Lippman dissented, as did Judge Read. So the decision was by four judges, Pigott, Smith, Graffeo, and Abdus-Salaam. Two of those judges are appointees of a limited government Republican governor, George Pataki. Judge Graffeo’s term expires at the end of the year. She could be either reappointed, which New Yorkers deserve, or replaced. Judge Smith turns 70 this summer and must retire.

The editor of the Sun, writing today in the New York Post, suggests that Justice Tingling would be an ideal choice to replace Judge Smith. We agree. For even though the Court spoke clearly and resoundingly, it did not do so by a large margin. This is a moment to maintain humility and be alert. All the courts that have looked at this leave open the possibility that the legislature does have law-making authority to address the diet questions. We dispute that, but the courts did not. So attention will need to be paid that the city council or state legislature does not step in to take away our freedom of choice on what to eat or drink. Welcome to the new age.