When Lawrence H. Summers was confirmed as treasury secretary last week, he became the latest in a long line of Harvard professors--from former Secretary of State Henry A. Kissinger '50 to former Council of Economic Advisers Chair Martin S. Feldstein '62--to assume high-profile government posts.

And while some colleagues say they are surprised the focused professor they knew has adapted so well to political life, Summers, an academic star from the start of his Harvard career, never left any doubts about his capabilities.

He earned his Ph.D. from Harvard, with a 280-page dissertation entitled An Asset Price Approach to the Analysis of Capital Income Taxation, and after a stint at MIT, went on to become the youngest tenured professor in Harvard's history in 1983.

Several years thereafter, he was appointed to a prestigious endowed chair and later won the John Bates Clark medal. In the past, recipients of the medal have often gone on to win the Nobel Prize.

"Larry is one of the smartest people I've ever met," says Professor of Economics N. Gregory Mankiw. "He's extraordinarily quick on his feet, in his ability to think through something he hasn't seen before."

Summers began his political career shortly after his graduate studies. Beginning in 1982, he served as a member of the Council of Economic Advisers under Feldstein, his former dissertation supervisor, who was chair of the council at the time.

But despite his early work in politics, many of Summers' colleagues say they were surprised he adapted to political life so easily.

"Larry had a reputation for being very blunt, for always telling you what he thought. If he thinks something's stupid, he'll tell you," says Mankiw, who served as Summers' assistant while Mankiw was a graduate student.

"I thought that wouldn't go over particularly well," Mankiw says. "My understanding is that Larry has become a lot more tactful."

And his colleagues remember him as a rumpled academic rather than a slick politico.

"His dress has improved," says Professor of Economics David M. Cutler. "He used to be sloppier. It was not uncommon to see him with his shirt not tucked in and his tie not on straight."

As a Clinton appointee, Summers is likely to be hunting for a job again in 18 months, and some analysts say that since he is serving under a lame duck president for such a brief period, he may have a difficult time implementing an ambitious agenda.

"If I could choose a time to be treasury secretary, this might be the worst time," Mankiw says.

Cutler says he hopes that Summers will return to Cambridge eventually.

"Typically people go and come back and Larry has not ruled out coming back," Cutler says. "I know he thinks quite highly of his time at Harvard."