The last time University President Lawrence H. Summers publicly ruminated on the capabilities of the opposite sex, he ignited an international brouhaha that would eventually taint his presidency. But as the unlikely keynote speaker at a women’s leadership conference yesterday morning, Summers received a far different reception.

Speaking to a predominantly female crowd gathered in a Charles Hotel conference room, Summers emphasized the “profound importance” of women’s leadership, receiving extended applause at the end of his 30-minute speech and words of praise from numerous audience members.

But it was a prickly subject for the embattled president, who made headlines last year when he hypothesized that “issues of intrinsic aptitude” might partially explain the dearth of females in science and engineering fields.

“You can imagine that I was a little bit puzzled as to what I should say in speaking to a conference on women in leadership,” Summers joked at the beginning of his remarks.

Grasping a tightly leashed microphone while casually leaning against a podium, Summers appeared comfortable with the audience of nearly 100 people, speaking without notes and cracking the occasional joke during his half-hour-long remarks.

Summers said that since January 2005, when he delivered his now-infamous remarks at a National Bureau of Economic Research (NBER) conference, he has learned that “the preconceptions that I had were wrong.”

“I spoke in ways...14 months ago at the NBER that I obviously would not speak today if I had to do it over again,” he said, adding that in that speech he was “reflecting on things I didn’t understand” and that he failed to anticipate “the way that certain kinds of speculations would be taken.”

But Summers did not back away from his controversial remarks completely. He emphasized the need for “the most vigorous possible debate” in discussing gender issues and said that both popular and unpopular viewpoints must have an opportunity to be vetted.

Summers also stressed the need to ensure that employers are “fishing in the largest possible lake” when they are looking for women leaders.

“Those who deny themselves access to a portion of a pool of talent are not just discriminating or being unfair,” he said. “They are sacrificing their opportunity to be excellent.”

At Harvard, Summers said the University can make progress by alleviating responsibilities for families with young children. Summers said that a “significant part” of the $50 million allocated last year to sponsor diversity initiatives will be used for that very purpose.

“Frankly, the easy part is putting resources behind the efforts at wealthy institutions like Harvard,” Summers said. “The hard part is addressing some of the many kinds of challenges that arise.”

In introducing the outgoing president, former Kennedy School of Government Dean Joseph S. Nye said that he hoped Summers would join the Kennedy School faculty upon his return to academia in 2007.

The Harvard Corporation has offered Summers a prestigious University professorship if he returns to campus after a yearlong sabbatical. But Summers, who was formerly the Ropes professor of political economy in the Faculty of Arts and Sciences, has not specified where he would maintain an office as a University professor. In his resignation letter last month, he said only that he plans to study “questions of national and international economic policy.”

Yesterday’s conference, entitled “Leadership 2006: Women/Leadership,” was sponsored by the Kennedy School’s Center for Public Leadership.

—Staff writer Javier C. Hernandez can be reached at jhernand@fas.harvard.edu.