Five hours after receiving a stern censure from the Faculty of Arts and Sciences (FAS), University President Lawrence H. Summers received a round of applause from undergraduates in Mather House last night.

Summers arrived nearly 30 minutes late to the Mather event, but House Master Sandra Naddaff nonetheless welcomed the president with open arms, a glass of Diet Coke, and a fresh slice of cheese pizza.

“I could use some sustenance,” Summers said. “I’ve had a long day—and I’m not going to talk about that.”

Instead, Summers launched into a wide-ranging talk outlining his overarching vision for the future of the University—leaving little doubt that, despite calls for his resignation, the president is in it for the long haul.

Battling back yawns at the beginning of his speech, Summers shed his suit jacket—and his look of fatigue—as he reiterated his call for curricular reforms aimed at bolstering the quality of undergraduate science instruction.

But Summers also sought to defuse criticism that he prioritizes the hard sciences over the humanities. Historically, he said, Harvard has been “more successful in training people and developing skills in the humanities...than we have been in the sciences.”

“The sense is not that science is more important at all,” Summers said. “It’s an area where we have a longer way to go.”

Summers described the University’s proposed expansion in Allston as a “profound opportunity”—both for improving laboratory facilities and for shaping the future face of Boston.

When one student questioned Summers’ decision to export the science departments across the river while the Law School remains in Cambridge, the president presented a vigorous defense of the University’s Allston blueprint.

He said that community resistance in Cambridge prevented the expansion of science facilities north of the Yard. He said University planners had found that even if the Law School did move to Allston, the school’s buildings could not be converted into lab space. And he said the move to Allston would help FAS scientists collaborate with colleagues at the Medical School and the School of Public Health.

Responding to a question about his now-infamous January remarks on women in science at the National Bureau of Economic Research (NBER), Summers outlined a broad four-point agenda to alleviate the pressures faced by faculty members with young families.

First, Summers said, scholars should be allowed to spend more years as assistant professors before the University issues a final decision on their tenure fate.

Second, Summers said Harvard should allow professors to pursue flexible work arrangements, including part-time options, while they juggle family responsibilities.

Third, Summers said the University should subsidize day care for faculty members with children under age six—just as it offers interest-free loans to cover tuition costs for professors with college-aged kids.

Fourth, Summers said the University should provide “an extra little bit of assistance” to scientists with young children—in the form of a technician or a research aide—so that faculty members can spend less time in the laboratory and more time with their families.