Uncertainty reigned at Harvard yesterday as professors and students struggled to assess the future of the university’s president, Lawrence Summers, after he unexpectedly lost a faculty no-confidence vote.

“I was very much surprised,” a professor of government, Jennifer Hochschild, said. The no-confidence motion won the support of nearly 52% of the members of the Faculty of Arts and Sciences who attended the contentious meeting on Tuesday. “I was thinking 30%, 40%,” she said.

A resolution offering a milder rebuke of Mr. Summers also passed, but Ms. Hochschild said some faculty members decided that measure did not convey fully the anger of many professors towards Mr. Summers’s leadership.

“A fair number of people said, ‘No, that wouldn’t have been enough.’ They wanted to make it really clear we’re not kidding around,” she said.

Ms. Hochschild said the president’s critics came from several camps. One group remained upset with Mr. Summers’s comments in January in which he said innate differences between men and women are likely to explain some gender disparities in university hiring. Another set of professors had grievances about what they portrayed as Mr. Summers’s autocratic governing style. “Those mostly weren’t the same people,” said Ms. Hochschild, who said she voted for the mild rebuke but not for the no-confidence motion.

The vote by the Faculty of Arts and Sciences was deplored by some at Harvard’s professional schools.

“You can’t underestimate the cowardice, the sniveling cowardice, of some faculty members who would only vote this way on a secret ballot,” a law professor, Alan Dershowitz, said. The vote “shows how out of touch some arts and science professors are with the real world. These guys ought to get a day job or a night job,” he said.

Mr. Dershowitz said he believes that much of the vitriol directed at Mr. Summers stems from his public denunciation of efforts to force Harvard and other schools to divest of investments in Israel. “This is payback primarily from the hard left on the Faculty of Arts and Sciences who can’t forgive Summers for what he said about Israel,” Mr. Dershowitz said. He noted that an earlier draft of the no-confidence motion mentioned divestment, though the no-confidence motion that passed last night did not mention any specific issues.

Mr. Dershowitz said a faculty meeting is not an appropriate forum to debate the accuracy of Mr. Summers’s comments on gender disparities. “Larry may be right, he may be wrong,” the law professor said. “You can’t decide if something is true by having a bunch of English professors vote on it. The process is terrifying.”

The vote put the faculty at odds with many of the students they teach, according to a Harvard senior, Joshua Mendelsohn, who has been organizing support for the embattled Mr. Summers. “We’re just incredibly disappointed with a lot of our professors. We feel strongly that academic free speech took a hit last night, that a man was unfairly punished for doing his job,” Mr. Mendelsohn said.

While many professors describe Mr. Summers as authoritarian, students say he is more accessible than any Harvard president in recent history. Just after the faculty meeting where he was censured, Mr. Summers visited a campus dormitory, spending an hour talking with undergraduates about their concerns.

Students have praised Mr. Summers for expanding financial aid and for promising to create more interaction between undergraduates and tenured faculty.

The vote, while a blow to Mr. Summers’s prestige, was essentially symbolic. Only the fellows of the Harvard Corporation can fire the president. Late Tuesday, they issued a statement that seemed to stress that the discontent with Mr. Summers appeared to be limited to only one of Harvard’s 10 schools. “The members of the corporation fully support President Summers in his ongoing efforts to listen thoughtfully to the range of views being expressed by members of the university’s faculties,” a corporation member, James Houghton, said. “We of course take seriously the views of faculty across Harvard.”

Mr. Summers was traveling yesterday and unavailable for comment. Speaking to reporters after the meeting, he gave no indication he was considering resigning. A professor who supported the no-confidence motion, Everett Mendelsohn, said it was too early to say whether Mr. Summers would resign. “A vote of lack of confidence of this sort does constrain his ability to carry out activities of any magnitude for a while,” the science history professor said. “It’s hard to figure out what he can do when so much of any leader’s ability depends on understanding and trust by those who are being led.”

At the faculty meeting, some professors criticized Mr. Summers for his statements of contrition. “It is somewhat difficult to defend the academic freedom of a man who seems to have surrendered it again and again, in his ever more abject apologies,” a history professor, Stephan Thernstrom, said.

Some in attendance said the strident speeches by Mr. Thernstrom and other conservatives may have actually cost Mr. Summers some votes among the largely liberal faculty. Mr. Thernstrom said last night he had “no idea” whether his oration helped or hurt Mr. Summers. “I also don’t particularly care; what I was interested in defending was not so much Larry Summers the person, as the principle of academic freedom.”