Under a heavy blanket of police protection, a group of prominent government and industry consultants met here recently to vent their mutual frustration about the difficulties of exercising their unusual specialty - development of strategies to eliminate political terrorism.

At a seminar on terrorism and the ways to combat it, the panel of consultants said many of the principles of industrial democrats such as the United States and West Germany are in fundamental conflict with measures needed to control the spectacular recent increase in the number and scope of terrorist activities.

"The terrorist is the cutting knife against the throat of civilization," said Aaron Katz, an organizer of the conference and author of more than 100 articles on the subject.

". . . Species survival in the end may confirm the necessity for a denial of constitutional protections of society in favor of rude and extreme measures initiated by society as if follows society's basic law - survival," said Katz.

Like Katz, the others who participated in the two-day seminar were professionals or academicians who have specilized in studying terrorism and in advising governments and businesses on how to deal with it.

It is unlikely, though, that when they agreed to participate in the seminar, they anticipated it would put them on the fringe of a scenario much like the ones they are paid to study.

On Sept. 22, just four days before the start of the conference, the president of the San Juan chapter of the Federal Bar Association, the principal sponsor of the conference, was assassinated, apparently by a terrorist group, in the first political murder ever to take place here.

The murdered attorney, Allan Randall, was a leading management representative in union disputes on the island. A note left at a local newspaper by an unidentified group also mentioned the conference as a reason for the shooting.

As police and government officials here labored to arrest the killers and hold down the impact of the shooting the Federal Bar Association canceled its annual convention, scheduled to coincide with the conference.

"Talk about ways of encouraging terrorism," a participatnt snorted. "They couldn't have made a worse decision."

The assassination wrapped a cloak of tension around the proceedings, as scores of policemen patrolled the conference area at the Caribe Hilton Hotel throughout the seminar. There were no incidents at the conference.

Most of the panelists agreed that the key to controlling terrorism lies in the kinds of surveillance and infiltration of dissident organizations that the FBI and Central Intelligence Agency have said they have abandoned in the wake of the recent outcry against their intrusions on personal privacy and freedom of association.

"With the limitations - in the sense of legal rules, legal procedures, lack of training, etc. - law enforcement is not in a position to suppress the terrorist movement as it is presently equipped, presently organized and presently functioning," said Stefan T. Possony of Stanford University's Hoover Institute for War and Peace, a conservative think tank.

"In fact, it's likely to get worse," Possony said. "You have a political problem on your hands."

It is politics, he said, that prevents use of tools which could bring terrorism under control - increased electronic, mail and phone surveillance of citizens, and new and more restrictive systems of passort surveillance.

"The mania with privacy has become a fraud on the American public," said Patrica Atthowe, president of Research West, a California-based company that advises businesses concerned about possible kidnapings and sabotage.

"What the government is saying is that we will keep you safe from the FBI and leave you safe from the Weathermen." The Weathermen, now known as Weather Underground, are a violence-espousing spinoff from the Students for a Democratic Society, a campus radical organization of the 1960s.

Displaying two "urban guerrilla manuals" published in California that detail how to make explosive and na-palm devices and pictures leading businessmen and their homes, Atthowe called for limitations on First Amendment rights in order to prevent publication of such materials.

The First Amendment came in for a beating from panelists at the seminar. "To the extent that democratic nations are unwilling to curb press freedoms, terrorists are free to manipulate the media for intimidation and blackmail," said Yonah Alexander, director of the Institute for Studies in International Terrorism of the State University of New York.

Alexander listed the press as one of the 10 leading contributors to terrorism in industrial societies. Among the others were:

The physical difficulty of defending societies dependent on sophisticated and vulnerable systems of communication and transportation.

Disagreement about who is a terrorist. "One man's terrorist is another man's patriot," he said.

A loss of resolve by governments. s "To counter terrorism, governments must strengthen surveillance," he said, using wiretaps, informers and infiltration of suspect groups. "In the U.S., congressional action has been moving to weaken, rather than strengthen, the FBI and CIA at a time when terrorism is increasing;"

A lack of understanding of the causes of terrorism, which he said include economic deprivation, social or religious conflicts and denials of human rights. "Sometimes these are legitimate views, and they can't articulate them," he said. "They're desperate."

The conference also offered one participant's rather novel look at terrorists themselves.

"We are laboring under the misconception that terrorists are highly motivated dissidents," said Possony, who is described by others in the field as "extremely highly regarded" and "one of the most highly respected analysts," of terrorism.

What terrorists are more likely to be, Possony said, are people who suffer from "basic perversions" that find expression in political violence.

Singling out Ulrike Meinhoff of Germany's notorious Baader-Meinhoff Gang, and Patricia Soltysik of the ill-fated Symbionese Liberation Army, Possony said "the key" about women who lead terrorist groups is that they are usually "bisexual females."

Sado masochism "is significant, crucial among the leaders of terrorism," he said, producing "unfliching courage and a resistance to threats."

Conference participants did find some small sources of hope. Brian Jenkins, associate head of the social sciences department of the Rand Corp., a leading consultant to the U.S. government, said steps some European governments have already take to control terrorism by limiting personal liberties show "how easily democracy can sustain limitations in the name of security."