THE MORAL DETECTIVE chews Pepperidge Farm Goldfish, swills his beer and sums up an unusual case, one he has just concluded after seven years of investigation. Fortunately, he says, there is no statute of limitations on this crime of conscience, which took place 30 years ago. A terrible mistake was made then--the innocent were confused with the guilty--and the record must be set straight at last.

Leaning forward confidently in a darkened hotel bar, the detective adds that the case has held a long and strange fascination for him. Clues began to appear when he was a young man. First, he noticed that a high-school girl friend had an Oscar on her mantelpiece, although her father worked as a parking at tendant. Then, during his college years, he was a bell-hop at a summer resort, where a middle-aged man in poor health taught him to play chess. The man could play several games at once. blindfolded--which seemed the only extraordinary thing about him until the FBI came to the hotel and the newspapers announced that the man was a communist. Years later, when the future detective started a magazine of political satire with two friends in law school, one of the friends asked that his name not appear on the magazine masthead, because "subversives might take over after we've left, and then we could get into trouble."

The detective pauses, stroking the underside of his gray-black beard, before explaining that all three clues pointed directly to the same moral-crime syndicate. The conspiracy, however, was actually much larger than it first seemed, involving not only cowards and congressmen, but also journalists, lawyers, psychiatrists, the American Civil Liberties Union, Hollywood, and Harvard.

Although a complete accounting is impossible, most of the victims have now been found, he says. They included actors, writers, directors, American culture, and the right of free expression. The father of the high-school girl friend, for example, had been a prominent scriptwriter before he was blacklisted for "subversive" activities and forced to find work parking cars. The chess teacher was J. Edward Bromberg, an actor who died shortly after he was compelled to testify before the House Un-American Activities Committee in ill-health and against doctor's orders. The law school friend's mother had gone to jail for refusing to divulge the membership lists of either the Civil Rights Congress or the Joint Anti-Fascist Refugee Committee, and her son kept it a secret from his closest friends. The suffering of popular culture and civil liberties in the Hollywood blacklist era are less quantifiable, but nonetheless real.

IF HE HAD BEEN born 25 years earlier, Victor S. Navasky, editor of The Nation and author of Naming Names, a "moral detective story" into congressional investigations of Hollywood in the 1950s, would certainly have been a victim of the McCarthy era blacklists. His liberal credentials as a former editor of The New York Times and author of Kennedy Justice place him squarely in the "effete," "pinko" intellectual establishment that bore the brunt of McCarthy's character assassinations. Navasky knows this, and there is a bitter urgency about his reexamination of the '50s, whether he is writing persuasively in Naming Names or speaking quickly In a hotel bar. Here is a man who wants to prevent history from repeating itself, both for himself and his nation.

There is little compassion in Naming Names, although it is scrupulously fair. Focusing on the role of informers in the "degradation ceremonies" of the House Un-American Activities Committee, Navasky interviewed dozens of former witnesses, both those who resisted the committee on First or Fifth Amendment grounds and those who cooperated with Congress by naming the names of friends, family and associates sympathetic to the Communist Party or other "subversive" organizations. In Naming Names, the moral detective first reconstructs these interviews, allowing the informers and resisters to speak for themselves, before he picks apart the justifications for informing and then explains the legal, moral and sociological imperatives for resistance.

"I wanted to find out why decent people--people like you or me--could do a very indecent thing," Navasky says, adding, "I picked informing because it seems so base, so clearly immoral--'finks', 'rats' and squealers' are universally condemned in all societies."

One-third of the Hollywood figures subpoenaed by Congress chose to name names in order to avoid imprisonment or blacklisting. Most of these "friendly" witnesses rehearsed their public testimony in prior, closed sessions with individual congressmen or committees. With few exceptions, the names they gave to Congress were already known to the committees and the FBI. The point of the McCarthy hearings, Navasky says, was not to gather information for legislative purposes, as HUAC's charter stated, but to force private citizens to degrade themselves in order to prove their loyalty. Those who betrayed their natural moral impulses were made heroes by Congress and the press. Those who reserved their principles and their silence were deprived of work and reputation.

NAVASKY MAKES IT clear, however, that individual acts of cowardice before congressional "investigators" were possible largely because the liberal "support system" failed to unite in opposition to McCarthy's principles. Many prominent institutions and individuals, such as Harvard, Yale, The New York Times, the film studios, Arthur Schlesinger, Jr., and Ronald Reagan, criticized McCarthy's tactics but conceded Congress's right to ask citizens about their political affiliations.

No one who was not a victim of the Congressional investigations, Navasky says, has a right to forgive the indivuduals who informed or the institutions that made informing possible. "The most I can do," he adds, "is say that they were wrong, that we must safeguard our morals under pressure, and that we have a great deal to learn from those few who resisted and ultimately prevailed."