Is a park still a park when it is home to a private hotel and several luxury high-rises? This is a question for philosophers, a state judge decided yesterday as he dismissed a lawsuit that challenged the city’s plan to transform an 80-acre parcel along the East River waterfront into a park.

The strip of land at the center of the dispute is a 1.3 mile length of mostly abandoned piers, sheds, and lots that some Brooklynites have wanted to see become parkland for decades. But the plan the state approved this year with the city’s backing has angered some park activists because it calls for land to be leased to private developers. The revenue, proponents of the plan say, would be enough for the park to be self-sustaining.

A group of neighborhood park enthusiasts, The Brooklyn Bridge Park Defense Fund, supported by the local Sierra Club, sued in state court this year, claiming that the plan violated the state’s public trust doctrine by handing over parkland to developers.

The judge, Lawrence Knipel of state Supreme Court in Brooklyn, struck down that claim. The parcels that will go to developers, Judge Knipel ruled, “are not parkland, have never been parkland and were never designated to become parkland.”

The decision suggests that Judge Knipel found more than only legal arguments in the court papers. Underlying the case, Judge Knipel wrote, ” is a fundamental disagreement” over whether a park should be designed with bringing in revenue.

“While this court is sympathetic to petitioner’s position that parks should not be burdened with the cost of their own maintenance, this is a disagreement of philosophy, not law,” the decision says.

The city’s and state’s “determination that the Brooklyn Bridge Park should be established, but not supported at the public’s expense may be philosophically regrettable, but is certainly not unreasonable or unlawful,” the judge wrote.

The president of the Park Defense Fund, Judi Francis, promised an appeal.

In an interview, Ms. Francis said Judge Knipel had “split hairs” when he decided that some of the land to go to developers had never been parkland in the first place.

“If it acts like a park, and has been talked about like a park, then it is a park in every sense of the word,” Ms. Francis said.

City officials said the ruling would allow construction to move forward.

“We are gratified that the Court ruled that the development of Brooklyn Bridge Park may proceed as planned,” the commissioner of the city’s Parks and Recreation Department, Adrian Benepe, said, in part, in a statement sent via e-mail.