On the afternoon that Malcolm Potts and Raymond Dennehy prepared to debate abortion in a lecture hall filled with UC Berkeley students, a noisy confrontation took shape a few dozen yards away in Sproul Plaza.
The Berkeley chapter of Students for Life had invited an antiabortion group that specializes in traveling photographic displays of bloody fetal parts to erect its provocative images comparing abortion to the Holocaust and lynching.
It didn't take long for an angry counter-demonstration to form around a hastily painted sign: "Abortion providers are heroes. . . . No Christian fascist theocracy."
The cacophony was precisely the opposite of what Potts and Dennehy have tried to model. Each semester for the last 10 years, they have debated in front of 400 undergraduates in a public health class. In a sea of rancor, their two-hour debates are civilized and gracious little islands that are almost (but not quite) tension-free.
"Dr. Dennehy and I are serious people who respect each other and have become friends over the years," Potts told the class as it met last fall. "We don't abuse each other. We don't try to spin data or philosophical interpretations in unreasonable ways."
Dennehy, 75, is a dapper professor of philosophy, bioethics and epistemology at the University of San Francisco.
He argues that abortion is almost certainly the killing of an innocent human being and that the Supreme Court's 1973 Roe vs. Wade decision, which has led to about 1.3 million legal abortions a year, "has had the effect on democracy that an atomic bomb would have on any city."
Potts, also 75, is a rumpled, British-born embryologist and gynecologist who has worked to make the procedure available to women in developing countries.
He contends that it is scientifically impossible to determine when life begins, but concedes that "I would rather destroy a five-week embryo than a 15-week embryo, and I accept there is some stage in pregnancy that you have to say no."
The two men have been on the front lines of the abortion debate for more than 40 years.
Dennehy has been going to Berkeley for this debate for 46 consecutive semesters, invited by students who knew he was a high-profile abortion foe. Before Potts arrived a decade ago, Dennehy faced off with the American Civil Liberties Union, Planned Parenthood and the National Organization for Women. One time, no opponent showed up, so he sparred with a video.
On this day, as often happens at Berkeley, most students aimed questions at Dennehy:
How you do feel about women who get pregnant by rape?
You've talked about babies' rights; what about women's rights?
What about pregnancies that put a woman's life at risk?
Dennehy was unwavering. A woman can abort a fetus only to save her own life. In all other cases, even rape, abortion is tantamount to murder.
"Have you ever been raped or been pregnant?" a young woman demanded.
You could almost see Dennehy rolling his eyes.
"Suppose I said yes," he said, unable to keep a slight snippiness out of his voice. "What's your next move?"
"I was just curious how your opinion would have changed if you were in that situation."
"What has that got to do with the validity of my argument?"
Her gambit failed; now she was on the defensive: "It's just a question."
"There are only two issues in an argument, miss," Dennehy said. "The facts, and the conclusions you draw from the facts.
"When we teach logic, that common fallacy is one of the first things we teach: shifting the attention of the argument and the evidence to the person arguing. It's absolutely irrelevant."
Potts sat attentively; students shifted a bit in their seats. If students thought Dennehy was going to play the avuncular, patient professor, they were wrong.
Dennehy, a Roman Catholic son of Irish immigrants and a father of four, began publicly arguing against abortion in 1969. Two years earlier, California Gov. Ronald Reagan had signed a law legalizing limited abortion. Dennehy became active in a local antiabortion group and was invited to make his case on a local radio station. After that, his debating career took off.
Each time he makes the trek across the Bay Bridge to debate Potts, he steels himself a little; he knows that, generally speaking, he is entering enemy territory.
Elegantly dressed in a gray suit with a tie and a pocket kerchief, his snowy hair swept back from his ruddy face, he kept the students slightly off balance, as when he joked about a rapist ending up at San Quentin ("where he may experience for himself the joys of homecoming queen").
In reproductive health circles, Potts, who pioneered the use of a small manual suction device for abortion early in pregnancy, is a highly regarded doctor who in the 1960s helped liberalize England's abortion law.
In 1972, he was part of a medical team that performed abortions for Bengali women who'd been systematically raped by Pakistani soldiers during the civil war that resulted in the creation of Bangladesh.
Potts was hired a decade ago by the UC Berkeley School of Public Health to fill a newly endowed chair in population and family planning, and his work has made him a target of abortion protesters.
Last spring at its annual conference, the Berkeley chapter of Students for Life handed out "Meet Malcolm Potts" fliers. Under his smiling photograph was a description of his accomplishments and this invitation: "Want to help stop him???"
Potts organized his presentation around a series of questions: Is abortion natural? Is abortion safe? Is it a healing process? (Yes, he said, to all three.) The process of reproduction, from conception to birth, is complex, treacherous and often ends spontaneously. Abortion in the earliest stages of pregnancy, he said, is entirely natural.
Dennehy never mentioned religion as he countered with a moral pitch: "If one doesn't think that it's always wrong to deliberately kill an innocent human being, then obviously, abortion is not an issue. But if you think it's always wrong to deliberately kill an innocent human being, then you have to give yourself pause before the issue of abortion."
But how would Dennehy answer Potts on the question of, say, "ensoulment"?
If, as Potts says, a fertilized human ovum does not split into twins until about the 18th day after conception, how can one say that life begins at the moment of conception? Can two souls share one embryo?
"Who knows when God did what?" Dennehy said. "This creature is produced by a human father and a human mother. If it's not a human being, what is it? It's very, very small. At a certain point, it looks no bigger than a typed period on a piece of paper.
"But we are producing silicon chips smaller and smaller that have hundreds of functions in their capacity, so the fact that it's very, very small does not mean it's not a human being, intact and self-assembling."
Many students appeared unconvinced.
A young man narrowed his eyes and raised his hand: "If you had to choose between stepping on a blastocyte and shooting a woman in the head, what would you do?"
"If I had to choose," replied Dennehy, "I think the answer is I would do nothing. And here again, that's called a fallacy of false alternatives. It's a nonissue."
The effort to stump Dennehy caught steam. Abortion is going to happen whether it's legal or not, said another student, so why not make sure it's legal and safe?
"Several years ago, the FBI reported almost a million cars were stolen, and car theft is against the law," Dennehy said. "And in that case, because people are going to do it anyway, what are your thoughts about making laws against auto theft?"
"Perhaps," injected Potts genially, "that is the fallacy of comparison." The audience chuckled -- not derisively, exactly, but they appreciated the point scored.
Dennehy conceded only this: "In terms of their own well-being, women are better off having abortions in hospitals than out in the woods with midwives. But there's one person abortion is always lethal for, and that's the fetus."
Potts got a single pointed query, from a young man who said his church works with women who regret having had abortions. "Are you belittling the damage done by abortion?" the student gently demanded.
"I am glad your church is helping those people," said Potts, who acknowledged that "a small percentage" of women have regrets. "But everything we do in medicine has a downside. Some people with cancer are sorry they have had operations. Some people have a cleft palate and are sorry it's been repaired because it gets infected."
It's hard to say if hearts and minds shifted.
Nicolas Anastasiades told Dennehy that he is "pro-abortion" and "a hard-headed bastard . . . and you have swayed me just a little bit."
But perhaps swaying wasn't entirely the point. When the two-hour class expired, the debate ended, not with warmth, but at least amicably. Outside in Sproul Plaza, the yelling had stopped.
Since their debate, a new semester has arrived, a new class has formed. On March 15, the two old foes will meet again.