AFEIXED TO THE BULLETIN board in the debate office at Regis High School in New York City are two photographs of David J. Kennedy. One pictures Kennedy as a National Parliamentary Debate Champion. The other, from USA Today, shows Kennedy at The Harvard Lampoon.

They still love Dave Kennedy at Regis. Like many others who will graduate from Harvard today, he burned his way through high school, wringing every ounce of achievement he could from the place and leaving it almost gasping with praise in his wake. Unlike others, however, Kennedy is remembered even today, the two pictures fixing his legacy at Regis.

"He's as well known by the present freshmen as he was by his own classmates," Regis debate coach Eric P. Di Michele says.

And why not? In a school that today boasts graduates who have won three of the last four National Parliamentary Debate Tournaments, Kennedy still stands out. He won not only Nationals but the World Universities Debating Championship as well, held at Oxford last winter.

He won a Truman scholarship as a resident of New York, perhaps the most competitive state in the nation, Next year he will travel to Seoul, South Korea on a Luce scholarship, and then he returns for Yale Law School--notorious even among lvies for the tiny proportion of applicants who are admitted.

Academically, he is "a professor's dream," as his mother predicted he would be. "Teachers often learn as much from their students as their students learn from them. I felt like I learned a lot from David," gurgles Associate Professor of Government H. W. Perry Jr., for whom Kennedy worked as a researcher.

Still, two pictures? Many students are bright. Many are successful. Many have even been the first in their families to graduate from college, like Kennedy.

But when you talk to Kennedy--or, more appropriately, when he converses with you--the two pictures become oddly necessary. A single photo can give you only an attenuated version of David Kennedy; One side of a coin. A joke without its punch line. Choose your own cliche--David is a "living, breathing paradox," as one of his friends put it.

"Everything I do, I always feel that there's, like, another me watching..., like there's this other me sort of keeping tabs," Kennedy says. "It's like having a second conscience."

Kennedy isn't saying he's a Dr. Jekyll and Mr. Hyde--two completely different people inside one, He's more like legendary lawyer Clarence Darrow, who won praise Iron athe ists for his defense of Darwinism in the Scopes trial, all the while remaining personally devout.

Kennedy fights constantly to strike a proper balance between incongruities. One David isn't private and a completely different one public--instead, a single Kennedy has built a thick wall between the two. One David isn't Irish Catholic, another cosmopolitan liberal--he tries to be both. One David isn't a social activist, another a flippant 'Poonster, reveling in the Castle's elite traditions--here, David is both.

But the struggle to find a personal equilibrium is difficult. And Kennedy is successful only part of the time.

ONE AUTUMN DAY A FEW YEARS ago, Anne Kennedy drove her son David to a nearby high school to take the SAT. A sea of cars buzzed around the parking lot, and Mrs. Kennedy knew there would be "a mob scene" after the students completed their tests. She asked David to wait at an intersection to avoid the crowds.

Four hours later, she found him standing just where she had asked him to wait--although now it was raining. Pouring, in fact.

"I got to the corner and there was no one else in sight," Mrs. Kennedy laughs. "Nevertheless, David was standing in a torrential rain,...wearing his new leather shoes and winter coat."

About a hundred yards away stood the relative safety of a building's overhang. David was not under it. "He follows the rules exactly to a tee," she says.