NEW YORK,AUG. 13 -- Saying that an anti-obscenity pledge required of all National Endowment for the Arts grant recipients is "vague" and "aimed at the expression of dangerous ideas," First Amendment attorney Floyd Abrams today asked a federal judge here to rule that the requirement is unconstitutional.

"What Congress is doing here is making a deliberate effort at suppressing certain types of speech," argued Abrams, who is representing the New School for Social Research, before U.S. District Judge Louis L. Stanton. "Congress did not like the language, expression, speech of Mr. {Robert} Mapplethorpe," the late photographer whose exhibit, which included homoerotic subject matter, touched off a storm of controversy last year.

The New School has refused to accept a $45,000 grant for the redesign of the sculpture on its campus and challenged the statute in a lawsuit filed in May.

Abrams said that the anti-obscenity statute, included by Congress in the NEA's fiscal 1990 appropriation legislation, was a direct result of the Mapplethorpe controversy. The statute forbids the NEA to fund work that might be deemed obscene by the NEA, "including, but not limited to, depictions of sadomasochism, homoeroticism, sexual exploitation of children, or individuals engaged in sex acts." Abrams said that some members of Congress were so incensed that public money supported the Mapplethorpe exhibit that they said openly in floor debate that the statute was intended to bar future funding of such projects.

"There is nothing in the Constitution that prevents the government from funding purely pastoral art," Abrams acknowledged in court. But Congress "has to say what they mean in a way for us to know what our limits are," Abrams said. The vagueness in the wording of the statute, Abrams stressed, forces arts organizations to "predict what they {the NEA} think is obscene."

Assistant U.S. Attorney Allan Taffet, representing the NEA, argued that endowment grants are voluntary subsidies to arts organizations. "There is no regulation, prohibition on recipients to raise private money to produce whatever art they wish."

Lawyers for the New School and the NEA presented final arguments today. Another lawsuit challenging the statute was filed last month by choreographer Bella Lewitzky in federal court in Los Angeles.