On a rainy day in October, 86-year-old Edmund Morgan is piloting his giant red Dodge Yukon around New Haven's narrow streets in search of a parking spot convenient to the restaurant he has in mind for lunch, the clubby Monty's.

Morgan has been a professor at Yale since the early 1950s and remembers when Monty's wouldn't admit women. "The food is not necessarily to be recommended," he tells PW, "but there's a lot of Yale's history to be seen on its walls."

The emeritus professor, retired from teaching for 15 years, should be a good judge. He taught both David McCullough and Joseph Ellis, and is considered by his fellow historians to be a national treasure.. President Clinton awarded him the National Humanities Medal in 2000.

Exasperated, Morgan gives up, and we return to his house, an Arts & Crafts home nearly as old as he is, in a lush part of New Haven. When we arrive, his dog, a year-old Shelty named Toby, greets us at the door, along with Morgan's second wife of 20 years, Marie, who ushers PW upstairs to help delete some troublesome spam among Morgan's e-mail. Before us is a translucent Apple PowerMac with an impressive cinema-sized screen. "He doesn't like to read e-mail on the computer, so I print it out for him," she says. "Then this," she adds, gesturing at the computer glowing red. Morgan appears at the door, with the pronouncement, "Computers cause more trouble than they're worth."

At his age, he can afford to ignore them. Morgan says he has written all of his books longhand. Though he admits to having been a student at Harvard of "the greatest intellectual historian of the 19th century, Perry Miller," he doesn't appear to belong to another era. An expert on the religious practices of the Puritans, Morgan made a name for himself with his early book, The Puritan Family (1944), and later with The Puritan Dilemma and Visible Saints, short works still used in history classes today. Inventing the People (1990) looked at the rhetorical hubris of politicians and businessmen; it won him the prestigious Bancroft Prize. His latest book, Benjamin Franklin (Yale Univ., Oct.), a short, lucid biography, has tapped into lingering interest in the founding fathers and brought him back into the public realm, where he's becoming an increasingly popular figure on television and radio, most recently appearing in a PBS documentary on Franklin. The book also became his first New York Times bestseller.

"It's the geezer factor," says Morgan, after we settle down to a snack of vanilla ice cream and pound cake. "There just aren't that many 86-year-olds writing books, so when they do, it's quite an event." Morgan deflects much of the interest in the book away from him, attributing it to Franklin himself, whom he describes as a man of action. "He was not a theorist and didn't believe in what he called 'metaphysical reasoning,' " says Morgan. In one of the most telling passages of the biography, Morgan dismisses the popular textbook image of Franklin as an old man with half glasses and a paunch as unfortunate, suggesting instead that the reader remember Franklin as a vital young man who was such a strong swimmer that he once leapt off a ship sailing from England to America and did laps around it for exercise. Our founding father had numerous careers in his life, including printer, scientist (yes, the incident of flying a kite in a lightning storm did happen), a diplomat and a statesman.

"The thing that surprised me most about Franklin was, why did he give up being a scientist and devoting his whole attention to public service," says Morgan. "He did that at a time when he was the leading scientist in the world, around 1750. He would have been 44. After he retired from printing, he could have spent his whole time on electricity. It surprised me that he did not." This comes from a man who after retiring in his 70s started a business out of his basement shaping wooden bowls, a project for which he cuts his own tools on a metal lathe; then he learned to fly.

According to Morgan, the best methodology for historical research is to pursue your own curiosity. "I used to tell my students to try and maintain the capacity for surprise," he says. "If you're studying the French Revolution and you come across something that surprises you, you have to ask why it surprises you. Most likely, it's because what you've read about the French Revolution before would not lead you to think that this would happen or that it had happened. So don't say, 'gee, I didn't know that'—you have to ask why you didn't know that. The likelihood is that somebody else gave you the impression it wasn't so." As such, when Morgan began writing his life of Franklin, he didn't read another biography of the man. Instead, he relied entirely on Franklin's letters and journals, most of which Morgan has himself read—twice—in his capacity as the chairman of the publishing board of the Franklin Papers, of which 36 volumes have been published so far.

Reading the primary texts goes to the heart of what Morgan sees as the mission of studying history. "You've got to take what people say seriously," he says. "Don't start with the assumption that they didn't mean what they were saying. It's up to you to show that they don't mean it if you don't think they mean it. All that postmodernism is junk. If the postmodernists are right, there's no point in studying history at all."

Asked about the most important lesson he's learned from his lifelong study, he replies, "No matter what people say, history doesn't repeat itself."