On a rainy Tuesday last winter, Dick Christensen told the seniors in his theology class at Gonzaga College High School, the private Jesuit-run boys school in inner-city Washington, to consider the following scenario:

Russian missiles are headed toward 10 American cities and there is not enough time to stop them. About 150 million Americans will die, including the president. The president must first decide whether to launch a retaliatory attack that would kill at least 150 million Soviet citizens.

If you were president, Christensen asked the students, would you order the strike?

Ten hands went up signifying yes. Who would not? Four hands crept upward. Two boys were undecided.

Christensen then told the boys who would "kill 150 million people" to sit on the right side of the room for the next several weeks and those who wouldn't, to sit on the left. The undecided went to the middle.

"I'll be honest with you. I am definitely on this side of the room," Christensen said, stepping in front of the "no-nukers," as they came to be known during the course of the six-week lesson unit. "And it's my goal to get all of you over to this side of the room. But my real purposes in doing this are two: First, I want to spark a dialogue, and second, I want to make you clear on your position on nuclear arms."

Had Christensen been teaching in a public school he might have been reprimanded for taking a stand on such a controversial subject and forcing his students to do so, too.

"For a teacher to press one point of view on an item where there is no consensus in the United States is very unwise," Montgomery County School Superintendent Wilmer Cody said when asked about this.

But at Gonzaga, a 164-year-old private school, it is the controversial and the uncomfortable that are valued as moral positions are explored.

"This course is difficult for a lot of kids," the 30-year-old Christensen said one day after class. "It puts kids on the line. But that's what life's all about . . . . They are coming from privileged positions and most likely will move on to privileged positions. The choices they make will have a real effect on others. As a result, as educators we have a real responsibility to develop their consciences . . . . "Studying Social Justice ---

Religious education has changed dramatically at Gonzaga since the vast reforms of Vatican II during the mid-1960s transformed the Catholic Church. One rarely hears the word Catholic in religion classes and discussion of values and moral dilemmas has replaced mortal sin and Catholic doctrine in most classes.

Christensen's social justice class for seniors provides a clear window on both the effort and, at times, the frustration of trying to take boys who come for an education in traditional academic subjects and send them away with a training in values as well.

Christensen knew he had a way to go that first day when he asked how many students believed nuclear war was "the unique menace of our time" and only one raised his hand. Christensen knew, too, that the odds were stacked against changing anyone's mind.

The core text was "The Challenge of Peace," a 150-page statement by the U.S. Roman Catholic bishops that, among other things, rules out nuclear attack on civilians for any reason. Most of the boys at Gonzaga were politically conservative. To vote not to retaliate risked being called a wimp.

The class's 17 members -- one student joined after the first day -- were a microcosm of the Gonzaga student body. Their parents did a variety of jobs. The father of one was a nuclear physicist, for example, another father a cook. Seven were sons of government workers; two were sons of lawyers.

Four were District residents, two were from Northern Virginia, 11 were from Maryland.

Christensen had come to accept the wide gap between the politics of the faculty -- 43 of whom were lay teachers and 16, priests or brothers -- and the students. President Reagan, not particularly popular among many of the teachers, was an imperial knight to most of the students. In the social justice class, 11 identified themselves as Republicans, five as Democrats and one had a parent of each party. Militarist Changes Mind --

Yet it was also clear that first day that the students would be, at times, unpredictable. One boy, for example, who for weeks before the nuclear war unit had portrayed himself as a hard-line militarist, stunned nearly everyone in the room by picking up his books and moving to the "no-nukers' " side. The decision was "easy," said the boy, who is going to college on a Navy ROTC scholarship. He asked not to be identified.

On the second day, David Costabile and Pat Ryan jumped from the undecided to the "no-nukers."

"I felt like having revenge . . . " Costabile, a Chevy Chase resident and star of the school play, explained nervously to the class that day. "But I went home and I thought about it, and I realized that it was absurd to think you could ever morally justify doing something like this."

The boy who was going to college on a naval scholarship realized that a year earlier, he probably would have been sitting on the other side of the room. But a course on Christian morality, a requirement for Gonzaga juniors, had changed his mind.

In that class, they had discussed the set of eight criteria for determining whether a war is just that has been endorsed by the Catholic Church and some Protestant churches. One of the tests of the "just-war" theory is proportionality -- the good achieved should outweigh the harm inflicted. Something clicked inside him that semester and he knew that retaliatory action and nuclear war could never meet that test. Now he was thinking about becoming a missionary after he leaves the Navy.

The "no-nukers" had vocal opponents in Pat O'Donnell, the stocky son of Irish immigrants, and John Douglas, a lawyer's son, who dominated the first few class discussions with arguments in favor of a counterattack.

Douglas, who was taking a course on F. Scott Fitzgerald and saw a lot of Gatsby in himself, acknowledged that life after nuclear war would be "completely different." "But if we did not attack the Russians they would have the ability to form any kind of government they wanted," he said after the second class.

Sometimes calm, sometimes forceful, Christensen never let up as he deluged the students with films, articles and essays arguing against the use of nuclear weapons. He did not present arguments in favor of using weapons because as a pacifist, he told one class, he wouldn't know how to present the other side.

From the beginning, the students were severe in their arguments. Advocates of a nuclear strike argued revenge and politics: Communism so threatened liberty and freedom that retaliatory action had to be taken to protect democracy for the survivors, regardless of how small their number. Opponents argued morality: Life is to be valued above all else.

"Just because we're not going to survive doesn't mean that human life shouldn't continue," said Greg Firehock, son of the chief of intelligence for the State Department's U.S. Arms Control and Disarmament Agency. "There is a chance of life continuing with the Russians."

"But then you're a Communist and everything is down the drain," responded Ryan Northrop, the son of a nuclear physicist formerly associated with the Defense Nuclear Agency.

"Who's a Communist? Your body?" shouted David Costabile, his cheeks burning. "You're dead. So what difference does it make?"

"Better dead than red," shouted someone else.

"We're talking about losing freedom," interrupted Pat O'Donnell. "The only reason there is freedom anywhere today in the world is because of the United States."

"So, Pat, you're saying that democracy and freedom are higher values than human life?" asked Dick Christensen. "Why aren't you willing to die for peace, Pat?"

Although O'Donnell argued the liberal position on apartheid and gun control at school debates, he was set on a strong defense. The son of a housekeeper who worked two jobs five days a week, and a carpenter who died seven years ago, O'Donnell wants to be a lawyer.

Nowhere else would he have the same chance for success as he had in America, he thought. Since his father's death, O'Donnell had held a series of jobs: paper carrier, short-order cook, a paster of flowers on car windshields.

In his heart, Christensen knew the students' anger was good. It meant they were being pushed. But sometimes the class was just too adversarial for Christensen, known among the faculty as a gentle person who avoided confrontation. The board chairman of a shelter for homeless women in the District, Christensen is married to a special education teacher and plans to enroll in medical school next year so he can serve the poor more directly.

The students did not seem to understand why Catholic social teachings -- in particular the bishops' statement against using nuclear weapons -- argued one position over another and that establishing values is not always a democratic process.

Although fewer than half the students participated regularly in class, many of the daily homework essays were marked by deep confusion and anxiety, underscoring Christensen's suspicion that the macho front of many students might not be all that it was built up to be.

"This article has moved me in such a way that I would personally like to go out and try to destroy every nuclear weapon that was made," wrote Tim Coakley after reading an account of a 16-year-old boy melting from the effects of the atomic bombing of Hiroshima. Nonetheless, Coakley, the youngest of five children and son of an alumnus, continued to argue in favor of launching a nuclear counterattack.

Coakley continuously teetered on changing his position. A Catholic who kneels to pray every night, he worried about his disagreement with the church's position against nuclear weapons. But he also said he was a person who "did not like to go down without a battle."

"When I told my mom that my teacher wouldn't counterattack because it would be morally wrong, she didn't say anything, but I felt like she was giving me this look that said I was wrong to want to kill 150 million people," Coakley said during the second half of the unit. "Maybe I'll switch . . . . I do feel guilty saying I'd want to kill 150 million people."

Several weeks into the nuclear unit, the boys began to view each other differently, and their arguments over the nuclear attack carried on after class.

David Costabile, a "no-nuker," angrily asked Pat O'Donnell after class why, if O'Donnell valued freedom more than life, did he not support abortion. O'Donnell answered that he believed in freedom for the fetus. Later Costabile got angry because he had not thought of comparing the fetus, an innocent bystander, to the 150 million Russians, who were also innocent bystanders in his eyes.

The student who was going to college on a Navy scholarship became furious when his friend John Douglas said the Old Testament, specifically the story of Cain and Abel, justified revenge. "It should be God who makes these decisions," the youth sputtered.

Wah Chan, the son of a man who fled Communist China, asked in one class, "Why should we play fair when they don't play fair?"

"That's what separates us, Wah. That's what makes us different," answered one student.

"Wah, why do you need a payback in the end?" asked Christensen.

"Maybe because I'm human," Chan responded quietly.Challenging the Bishops --

Christensen began to feel he was succeeding. The issues had stirred the students. "What gives the bishops the right to say I'm not a Christian if I would use nuclear weapons . . . , " John Douglas angrily asked near the end of the unit. "I don't believe in first strike. I want to make that clear."

"Well, what essentially are you fighting for?" shot back Charlie Phillips, one of the most articulate spokesmen for the no-nuke side. Phillips had been turned down for a Navy ROTC scholarship, but had been offered a spot in the Navy's precollege program in San Diego.

For the last three classes, Christensen wanted to bring nuclear war even closer to home.

For two days, students watched "Testament," a movie about a Northern California family after nuclear bombs have been detonated across the country. The script, when read by seventh graders in the Arlington public schools, had come under attack from "Parents for Academics," a 30-member group in Arlington that objected to discussion of sensitive moral subjects in the classroom.

In the film, the family's town is not struck, but the community slowly disintegrates from the radiation. A neighbor's baby dies and the family donates a bottom drawer to use as a coffin. The first of the family's three children dies, then the next.

Finally, the mother puts her son and a child whose parents have died into the family car in the garage. She stuffs the cracks and is about to start the engine to commit suicide, but cannot. The movie ends with the mother, son, and neighborhood child celebrating the son's birthday with tiny candles stuck to thin crackers.

The students were visibly disturbed as they left class those two days. John Douglas did not know what to think. His reasons to launch a nuclear counterattack seemed to outweigh his reasons not to, but he was not thoroughly convinced. The class had thrown a disturbing wrench in his ideology. O'Donnell was depressed by the movie. Coakley could not imagine living in a place like the town shown after a nuclear blast.

The students had eight days to prepare their final presentations, a five-minute speech defending their positions as if they were the president of the United States.

As Christensen began calling names on the last day, the boys looked at each other, wondering if anyone would switch. Christensen thought not. It would be too difficult for anyone to back down now. But he thought he had done his job well. He had planted a seed. Maybe four, maybe six, maybe 10 years from then, he thought, one of the students would have a change of heart. Maybe John Douglas. He might come around. He was conservative and thoughtful.Firing the Missiles -------

For the time being, though, Douglas was staying the course.

"My decision to fire the missiles was based upon my perception of the Soviet Union as I know it," began Douglas. "Peace was not the issue. The peace had already been destroyed . . . . Now, from what is left, we must struggle to start anew, as a phoenix rises from the ashes, and create a society in which such a thing can never happen again . . . .

"Many of you would say that I acted upon the impulse of revenge, and/or temporary insanity, and I won't deny that they may have played a part, but I did what I, given the authority by you to do, felt was the proper, and most correct thing to do."

The final tally was 10 "nukers" to 7 "no-nukers." No one had changed his mind after the second day. But the speeches gave Christensen some solace. Those who would kill 150 million Russians at least now realized the devastation nuclear war would bring.Next: Helping orphans in Mexico