Throughout his ambitious literary career, Mexican author Carlos Fuentes has never been afraid to cross boundaries. He has explored all genres from poetry to drama, from short story to essay. And within his favorite genre, the novel, he has also transgressed all boundaries, ignored them, and created a single entity in which history and myth, time and space, are all blended together.

The combination has made Fuentes possibly his country's most important author and one of the leading literary voices of Latin America, which remains a well-spring of ambitious new fiction.

For Fuentes, in the second of five years as a fall-term professor at Harvard, this disrespect for conventional boundaries is combined with an enormous reverence for the different elements which make up his novels.

History, for example, is one of Fuentes' main concerns. "I believe profoundly in societies that do not kill the past," he said in a recent interview in his Harvard office. In his work he constantly explores the influence of the past on the present and emphasizes this influence by breaking down the borders of time, letting the past and the present coexist.

Another boundary that disappears in Fuentes' work is that between history and myth. This mingling of fact and fiction can be traced back to the beginnings of Latin American history. At the very origins of Latin American history is the everpresent mythical tradition of the native inhabitants. In Mexico, the Aztecs are the people chosen by the gods to feed the sun and thus keep it moving. The arrival of the Spaniards in no way destroys this mythical tradition. Cortez' arrival, for example, is explained by the myth which tells of the redeeming God Quetzalcoatl who would come from the ocean to save the Mexicans from the evil god Huitzilopochtli. From its origins, history and myth become permanently linked.

In his novel "Terra Nostra" (1975), Fuentes sets out to reconstruct a mythical history of Latin America. In this 800-page work, fictional characters and historical ones appear together, past, present and future mingle as Fuentes narrates the birth of the New World. The novel focuses on the beginning of Latin American history when two worlds are brought together by Columbus: that of Spain, already a battlefield of the Arabic, Jewish and Roman cultures, and that of America with its native populations. "Terra Nostra" represents knowledge through imagination--a knowledge that cannot be found in the history books.

At an informal meeting at Cabot House last month, Fuentes told listeners that Latin American authors often have so much to say that even 1000 pages are sometimes not enough to say it. Yet in 800 pages of "Terra Nostra," which take us from the Roman Empire to the year 1999, that is what Fuentes attempts to do: to say it all, to write the total novel.

"Terra Nostra" is not the only novel which uses the interplay between past and present and between the diverse elements of Mexican culture. Fuentes' first novel "Where the Air is Clear" (1958) is a mythical history of Mexico City. In this novel Mexico's mythical past of rituals and sacrifices appears parallel with the present. In "The Death of Artemio Cruz" (1962), the story is narrated by the revolutionary turned opportunist of the book's title as he lies on his death bed. The story is told by multiple voices with a constantly shifting narrative and chronological viewpoint.

How does the reader fit into this complex structure of interwoven times and multiple voices? "Terra Nostra," for example, has often been considered unreadable by critics. Yet Fuentes emphasizes that in spite of its difficulty, it is a novel which does not go unread. "The Death of Artemio Cruz" and "Where the Air is Clear" were both considered extremely difficult and complicated when they first appeared. Fuentes tells of one critic who suggested that "The Death of Artemio Cruz" served no better purpose than to be flushed down the drain. "Today," Fuentes says, "these novels are read by 15 year-olds in Mexico. That is in great measure the destiny of literature, it ends up being accepted."

For the second year in a row, Fuentes is teaching a course--Lit and Art C-41, "History and Fiction in Spanish America"--which is a condensed and restructured version of "Terra Nostra." In the course, Fuentes traces the heritage of Latin America back to the different currents of thought which followed Columbus across the Atlantic. The New World became Europe's utopia: a place where Europeans could reconstruct their world without any of its faults. But as the invading Spanish and Portuguese driven by a Maciavellian thirst for gold and power, they did not face an empty continent. The history of Latin America is the history of the mingling of many cultures, of synchronism. Without understanding this history it is impossible to understand Latin America.

Underlying Fuentes' interpretation of Latin America's heritage is Gianbattista Vico's notion that man makes his own history. Time is not a limit to be respected; space is not a set of borders which confine us. On the contrary, space is something we search for and expand into.

Maybe this disrespect for borders can be traced back to Fuentes' own life as a citizen not of Mexico or of Latin America, but of the world. From the time he was a child, Carlos Fuentes never stayed for very long in one place. The son of diplomat, he spent his childhood in Washington D.C., Rio de Janeiro, Montevideo, Buenos Aires, Santiago and Mexico City. He attended the Universidad Nacional Autonoma de Mexico and then studied international law at Institut des Hautes Etudes Internationales in Geneva. He has traveled constantly and has been a member of the Mexican delegation to the Labor Organization in Geneva and Mexican ambassador to France.

Although he usually writes about Mexico, Fuentes needs to get away from his country to obtain the perspective which allows him to write. "This has to do with the fact that I grew up outside of Mexico," he says. "I am used to looking at the country from the outside." Fuentes feels that living in Mexico is something "very complicated and baroque." "I think there is a conspiracy in Mexico," he adds jokingly, "to prevent us from understanding what is going on due to the baroque and sometimes surrealist abundance of the elements around us."

And to gain the necessary perspective, Fuentes has often crossed the sometimes forbidden border which lies to the north. From the time he was a child growing up in Washington, Fuentes was influenced by American culture, where he recalls that one of his childhood memories is that of Dick Tracy. Subsequently, he has crossed and recrossed the border many times and has taught at a number of American universities including Dartmouth, Barnard, Columbia, Princeton, the University of Pennsylvania and Washington University.

Carlos Fuentes' relationship with the United States is an ambiguous one, a love-hate relationship. "Sometimes we welcome each other, sometimes we reject one another," he says of the U.S. When he was growing up in Washington, Fuentes experienced not only Dick Tracy, Citizen Kane and the New Deal but also the anti-Mexican feelings which developed during the late 1930s when Mexico nationalized its oil industry. Fuentes says he has since faced frequent trouble entering the United States.