John Womack Jr. knew there was such a thing as a Marxist historian before he had become either a Marxist or a historian himself. He knew this, dimly, from his history classes at Harvard in the late 1950s.

"But nobody who taught those courses took it very seriously," he says. "They tended to treat it rather the way in medical school they might have treated the theory of the humors--as if you could see why people believed it, but it didn't make much real scientific sense."

Now 45 and chairman of the Harvard history department, Womack paid a visit to Washington this week for the annual meeting of the American Historical Association, and between sessions he sat down over coffee in the Sheraton Washington and talked about how Marxism--his own undoctrinaire brand of it--has shaped his career.

The effects, so far as he can tell, have been all positive. "I have been treated very generously by my elders," he says. "That doesn't make me think that there aren't people elsewhere who have gotten screwed, who because of their politics have been badly scraped, if not scrapped--like Ollman, the guy who was here at Maryland. [Because of his politics, Bertell Ollman lost his appointment as chairman of the political science department at the University of Maryland.] I have very deep disagreements with him about what Marxism is or is for, but it seems to me that the kind of Marxist he says he is, it's a respectable school of Marxism . . . He's good at it, and it seems to me that he got a raw deal."

Womack may have profited from being a specialist in Mexican and Latin American history. "It's just less important," he explains. "Had I been a bright young student in Russian history and taken positions as perpendicular to American policy as some of the things I've said about Latin America, I think, yeah, my elders would have thought that I had a second-rate mind. Which is what you say when you disagree with somebody. You can't say, 'I disagree with the person politically.' You say, 'It's clear he has a second-rate mind.' "

Whatever the stereotype of a Marxist historian may be, Womack doesn't fit it. His speech has the unvarnished twang of a man born and raised in Norman, Okla., where his father ran a gas station. His dark good looks remind you that this is the part of the country that has given us John Wayne and Henry Fonda.

And there is nothing sentimental about Womack's view of history. Unfortunately, he says, Marxist historians have received less attention than "radical historians," who study "resistance or defiance by the little people." Womack does not care for this brand of history, "because you don't see whom [the people] are fighting with. It's like hearing about a troubled marriage from only one sympathetic side. Marxist historians--those that I like to think of myself as one of--are interested in what I guess you could call class struggle . . . in the character of the conflict itself."

Womack published his first book, "Zapata and the Mexican Revolution," in 1968, and on the strength of it he received tenure a year later, skipping one of the normal steps up in rank. Ever since, he has devoted himself to the study of Mexican labor and industry, a subject that becomes clearer to him, he says, when viewed from a Marxist perspective.

The traditional view of how peasants become industrial workers, he explains, is that "you start with one stable situation, and after a rupture . . . eventually you get readjusted in another essentially stable world. That is modernization. It's a process, it's very difficult, it's troublesome, but it has an end. And as I see these guys, I would say--and I think this is in crude terms a Marxist view--that there's no real adjustment either originally or eventually. You move from one kind of conflict [to] another sort of conflict. And these are conflicts that are driving. They accumulate trouble, and episodically they bring on crises of either a financial kind or a social kind.

"The simplest difference between the orthodox standard liberal view of these things and the Marxist view is that Marxists believe--they don't assume, but they keep finding--that the sense of things is really in tension and in conflict . . . which are essential and driving and dynamic." Marxists assume "that people aren't naturally happy," he says, "and that there's nothing that will make them ultimately happy."

Womack says he "veered into" his specialty after two years at Oxford as a Rhodes Scholar. "I applied to go for a fellowship back at Harvard to study politics and economics, but when I asked for a recommendation from the only professor I knew, he said, 'Look, we have this fellowship in Latin America. Why don't you apply for one?' And that was just at the time of the Bay of Pigs thing and the Cuban revolution, and it seemed important."

At Oxford and then at Harvard again, he helped organize student protests against U.S. policy toward Cuba. During the missile crisis, "with a few other people I hustled around Cambridge to try to get some opposition drummed against the urgent American academic inclination to bomb Cuba," he recalls. "If you talked to Harvard academics at the time, many of them were for just taking the missiles out. Brzezinski was a smart young assistant professor, and Kissinger was a professor."

But in the late '60s, when leftist views and the loud expression thereof became commonplace, Womack did not see the change as a dream come true. It was "too much theater: young people acting out stuff. While it certainly had some political effect, it dissipated quickly . . . It made middle America hate students and the cause that the students wanted to represent. At the same time, after the violence of these things got extensive, it may have scared a lot of people. And they then began to feel, 'It's just too much grief. The damn war is never going to end and look what it's doing.' I think now, if you just breathe 'Vietnam' about Central America, I think rightly people begin to get very nervous about it, because they don't know whether there's anything really at stake there, and they think, 'If I don't know, why should I risk domestic tranquility for some lunatic ideologically inspired undertaking by my government?' So I think the effects of '60s student radicalism were very negative, but somewhat positive."

Looking at his own current students, Womack espies a modest revival of political commitment these days. "But there was a period in there, after Nixon ended the draft and before Central America became a question--the period of Jerry Ford and Carter--when there were not a lot of hot issues."

In any case, he says, these trends are strongly influenced by what students learn from their parents. "The students of the '60s, to a great extent, were born during the Second World War or right after in the baby boom. It wasn't so much important what they went through but what their parents had been through. Their parents had gone through the New Deal and the Second World War, two great democratic, left-leaning episodes in their parents' lives . . . The children who have come to school in the '70s are mostly the children of the Korean War generation, and that's a different bunch. They are the children of the McCarthy period--not that their parents were McCarthyites, but it was a period of deepening conservatism in the United States. It'll be interesting to see what happens when the children of parents who attended college in the '60s wind up in college."

Womack says his political convictions are irrelevant to his current role as chairman of the history department. "The kind of politics I care about are about life, death and control of the means of production," he explains, "and none of these things are on the history department's agenda, thank God." Just about the boldest ideological sally he might introduce into a departmental debate would be the suggestion that "we have too much intellectual history" as against economic and social history, he says. But "you wouldn't say that because that would be offensive to somebody in the meeting. They'd say, 'Well, who's excessive?' But you could say, 'Thanks to our recent wisdom we now have abundant talent in intellectual history, so in our next appointments we should try to get an economic and social historian.' "

After his first book, Womack says, "I didn't expect to get tenure," and "in the full bloom of my youthful arrogance I assumed I would rip off another book or two before the question of tenure came up." But as it turned out, he has been researching his second book ever since, and only now feels ready to start writing. In the end, he figures, the book will take him 15 to 18 years. But "I think I've found out stuff that nobody else found out. Not just details, but something about the way things work in a society.

"If I can get it done and get it done right, I think it will be a very important book in the field. These guys who engineer hearts and work in molecular biology and so on, it takes them a long time, and I think it works the same way in history as it does in other fields. You can't program the discovery of what you don't know."