It is 1780, and you are a passionate abolitionist Quaker living in Philadelphia. You are also a representative in the state legislature, but more than that, you are the deciding vote on a momentous anti-slavery bill now before the assembly.

With your assenting vote, children born to current female slaves will be emancipated when they reach age 28 and their children will be free at birth. Vote no, and Pennsylvania will fail to become the first state to pass an abolition measure of any kind.

Tough choice.

The legislation would not free a single man or woman now living in slavery, which is your most fervent desire. You might even say the new law would validate the scourge of slavery, at least for the present. But, the bill will free some people someday. That's better than nothing, isn't it? And who says you can't come back tomorrow or next year or in 10 years and try for a stronger law.

So what do you do? Do you stand on principle and refuse to abide slavery in any version or do you hold your nose and approve a lily-livered half-measure?

Law students may have no easier time with this dilemma today than real life Pennsylvania legislators had more than two centuries ago. That's just too bad for those taking F. Michael Higginbotham's signature course "Race and the Law" at the University of Baltimore School of Law. But making these future lawyers squirm under the weight of decision - even hypothetical ones, like this one - is a measure of their professor's job satisfaction. Higginbotham, though as warm and convivial as any law professor is ever likely to be, is not here to make things easy.

In fact, Higginbotham, a youthful and fit 45, turns the screws tighter during this day's lesson on Pennsylvania's Gradual Abolition Act of 1780. He presents the students with a grim comparison between the international slave trade of the 17th and 18th centuries and the Holocaust. While some students may have taken refuge in the notion that slavery was a cruel but not a murderous practice, Higginbotham points out that more than half the blacks herded onto slave ships in Africa failed to survive the crossing.

Over the 300-year history of the Atlantic slave trade, the number of deaths was almost certainly in the millions. So, in a real sense, the perpetuation of slavery in America furthered a genocide, whether or not that was its purpose.

Looked at that way, Higginbotham tells his students, the oppression under slavery and the oppression under Hitler were of a kind. "If you look at intent, there's a big difference," he says, "if you look at result, no."

Comparison is the engine that propels American jurisprudence. The practice of law is essentially the delineation of similarity and distinction, the search for consistency and discrepancy. How does the case before us compare to these past ones? Does the precedent apply; if not, why not? Without such comparisons, our legal system would have no relevance, no authority. A court's rulings, unhinged from the past, would be arbitrary and most likely short-lived. It is only by looking backward that the law can move ahead.

And so, Higginbotham challenges his students to compare, but admonishes them to be clearsighted when they do so. Make sure when comparing sets of facts that you use the same measuring stick.

It's not so easy, not so obvious, particularly in the arena in which Higginbotham is making his name as a legal scholar. (He is the author of a legal textbook, Race Law.) When it comes to race, the history of law and public policy is not always fraught with logic and reason but with prejudice, bias and emotion. The trick, Higginbotham tells his students, is discerning one from the other.

Which is why one of the villains showcased in his course is a little-remembered but formidable, slave-owning judge named Thomas Ruffin who sat on the North Carolina Supreme Court in the early 19th century. Ruffin delivered the high court's opinion in State vs. Mann, a case involving a slave owner who shot and wounded his slave, Lydia, when she tried to escape.

The district court found Mann guilty of using disproportionate force against Lydia, holding that though Mann owned her, there were limits on his behavior. She was more than a farm implement that could be destroyed at will.

Ruffin didn't buy it. In overturning the lower judge, he held that no such limits existed in regard to slaves. Because Lydia was Mann's slave, he could deal with her delinquency any way he saw fit.

How did Ruffin arrive at such a ruling? What case law did he use in justifying his reversal?

The answer is clear if you study the record, Higginbotham says.

None.

Even in 1829 when slavery was entrenched in North Carolina, Ruffin didn't have a leg to stand on from a legal point of view. The existing precedents did perceive limits on slaveholders. Just as there were restraints on the behavior of parents over children, teachers over pupils and masters over apprentices, so were there limitations on slave owners. They could not inflict punishment out of proportion to the offense.

Aware of that case law, Ruffin ignored it. Instead, he asserted the slave owner's absolute authority over his slaves, whom, Ruffin declared, enjoyed no rights whatsoever. As far as Ruffin was concerned, the only factors governing the slave owner toward his slaves was his own safety and profit.

These maxims, however, did not arise from precedent; Ruffin, says Higginbotham, "just makes it up."

If Ruffin didn't rely on case law, what was the basis of his ruling? Higginbotham turns to the technique of one of his favorite fictional characters, Sherlock Holmes. "If you eliminate all the possibilities except one, no matter how unlikely or hard to believe, that one is the truth."

And what is the truth we are left with about Ruffin? "That he must view people in a racial way," Higginbotham says. In other words, he was a racist.

It's a sobering view of history and the law, but an instructive one. "In Mann, obviously a lot of options were available, but the choice Ruffin made was the harshest one for slaves and the reason ... had more to do with Ruffin's own values, including his prejudices, than it did with some objective rule of law."

It's a valuable lesson for historians and law students, Higginbotham says. History and law sometimes arise from bias and prejudice. It's important to recognize those traits in others. It's equally important to recognize them in yourself.

It was the Holmesian process of elimination that enabled Higginbotham to identify racism in his life when he encountered it. You might think that any young black man would have been alert to discrimination in the America of the 1970s, but Higginbotham acknowledges that his particular corner of America was a distinctly protected one.

Discrimination

When his father, Robert, an orthopedist and one-time Tuskegee Airman, took a new job in Los Angeles in 1971, the family relocated from the affluence of Shaker Heights in Cleveland to the opulence of Beverly Hills. One evening soon after the move, 14-year-old Mike was on his bike exploring his new environs when a couple of Beverly Hills police officers pulled him over. Where did he live? What was he doing there?

It took awhile before he could satisfy them, and even when the officers let him go, they warned him that there was a curfew for kids and they'd better not see him out again at night.

Not long after that, Mike was at a pool party, the only black among white kids. As darkness arrived, Mike said he had to be going. Why, his friends wanted to know. Because of the curfew, he said.

"What curfew?" they asked.

"Maybe there was a curfew," he says now with a smile, "but it was being selectively applied."

By his estimate, he was stopped 100 times over the years in and around Beverly Hills. "Sometimes when you're black," he says, "it's hard to tell if you're being discriminated against because you're black or because of your economic status." In his case, though, there wasn't much doubt. He wasn't poor. That left one explanation, and that one hurt. "My reaction was sadness. I thought, why is this still going on? I thought those battles had already been fought."

The discrimination didn't stop with the cops. Higginbotham, who loved sports, believed that some coaches in his overwhelmingly white high school retarded his athletic career because of racism. What gratified him, though, were white friends who felt as aggrieved as he did over how he was treated.

But the discrimination wasn't able to hold him back in the classroom, where he performed well enough to get into Brown University, Yale Law School and Cambridge University, which he attended for two years on a Rotary Scholarship.

Even before high school, Higginbotham realized he wasn't going to follow his father, Robert, into medicine. One dissection of a fetal pig cured him of that notion. On the other hand, his fascination with history convinced him that he wanted a career in law, a discipline that he intuitively understood to be backward-looking.

If neither his father nor his mother, Margaret, an art teacher, could expertly guide him, there was someone else in the family with ample credentials. His second cousin was A. Leon Higginbotham Jr., a towering figure in American jurisprudence who, at that time, was a federal district court judge after serving as president of the National Association for the Advancement of Colored People in Philadelphia. He would later be appointed chief judge of the 3rd U.S. Circuit Court of Appeals, teach at Harvard Law School and be awarded a Presidential Medal of Freedom.

After Michael expressed an interest in the law, Margaret turned to Leon for advice.

"He said he was going to be teaching that summer at the University of Hawaii and we should bring Mike over so he could have a look at him," says Margaret.

Instead of hitting the beaches, Mike accompanied Leon to class every day. At the end of the two weeks, Leon took Margaret aside. "I think he has it," Leon told her. "He asked questions that were better than the graduate students'." He promised to help Mike in any way he could.

He was true to his word. He remained Mike's mentor - and frequent collaborator on legal texts - until his death in 1998. In 1986, when Mike was at Cambridge, Leon asked him to join him on a trip to South Africa, where he was to attend a conference on the dismantling of apartheid, a trip that inspired Mike to write a series of law review articles.

One of Higginbotham's lasting impressions from the trip was America's pusillanimous position on apartheid. Years later, he would incorporate that disappointment into a question to his students in "Race and the Law." Under President Ronald Reagan, Higginbotham says, the rationale for the White House's toleration of apartheid was that some of the black insurrectionists were Communist.

Do you believe that? Higginbotham asks his students.

"If you say U.S. policy was to stand up against Communism wherever it existed, I ask, if the Communists had been white and the capitalists all black, what would we have done? Would our approach have been the same or different?"

Above all, Higginbotham asks his students, was the policy consistent?

By the time he finished at Cambridge, Higginbotham knew he wanted to teach law, not practice it. He had not been stimulated during the stints he had done in private law firms during summers and after Yale. More than anything, watching Leon teach, seeing how he brought history and the law alive, convinced Higginbotham of what he wanted to do. And he was given the best opportunity to get started when he got a teaching position at the University of Pennsylvania, co-teaching "Race and the Law" with Leon while living next door to him.

Two years later, he went in search of a professorship. That's how he came to the University of Baltimore in 1988.

It wasn't the most prestigious institution, but it appealed to him for several reasons. The school was in a sizable East Coast city, and he could teach the courses he was most interested in, including "Race and the Law." And, as he says, "They really wanted me.

'A matter of people'

It has been a happy marriage. Higginbotham, who has since received tenure, is one of the law school's most popular teachers. Students say he has the rare capacity to push them hard while leaving no doubt that he is wholly on their side.

"He has a great way of both challenging you and also making you feel that you have something to say," says Kathleen Bergin, a 1997 graduate now in private practice in Boston.

Another former student, Carroll James Harris, now an associate with a Baltimore law firm, remembers Higginbotham's great warmth. He ran into Higginbotham on his second day of law school. "He introduced himself and said, 'If there's anything I can do for you, come see me.' That really stood out to me. I wasn't even in his class then."

Michael Meyerson, a colleague at the law school, calls Higginbotham an extraordinary teacher because of his understanding that history and law are the outcome of passion as much as reason. "He understands that law is a matter of logic and history and policy, but he also knows it's a matter of people and morality and decency. He weaves them together."

People loom at least as large as legal text in Higginbotham's course. He says he doesn't want his students to forget that although the law exists in the intellect, it also lives in the world. That's why heroes in his course are people like John Newton, the captain of a slave ship who became an abolitionist (and author of the hymn "Amazing Grace"), and Lloyd Gaines, an African-American who fought all the way to the U.S. Supreme Court to win the right to attend the University of Missouri Law School, a victory that apparently cost him his life. He disappeared after the ruling.

Higginbotham does not subscribe to moral relativism in history. That is why the sainted Thomas Jefferson, founding father, author of the Declaration of Independence, intellectual bulwark of the American Revolution, emerges somewhat tattered in Higginbotham's course. Jefferson was a slave owner.

"Some say you can't judge Thomas Jefferson on slavery because he lived in a different time," says Higginbotham. "That's when I say let's look at George Wythe."

American revolutionary, judge, educator, plantation owner and signer of the Declaration of Independence, Wythe was mentor and friend to Jefferson. And, he opposed slavery. He pushed for a gradual abolition act in the Virginia legislature. In one of his judicial rulings, he held that the Virginia Declaration of Rights, which declared all men free, also applied to African-Americans. Wythe was overruled, of course. But that didn't prevent him from freeing his own slaves.

Knowing about Wythe, Higginbotham asks, why would you excuse Jefferson? "Be consistent," Higginbotham says. You shouldn't make allowances for Jefferson for not living up to worthy human ideals when others in his own time were.

In that light, Higginbotham says, "George Wythe stands up to the test of time; Thomas Jefferson does not."

Compare, compare, compare.