During a day-long event to mark his 70th birthday, Summers basked in praise from guests including former Meta chief operating officer Sheryl Sandberg and Gene Sperling, who directed the National Economic Council for Presidents Clinton and Obama. This week, a chastened Summers found himself in different circumstances: standing in the well of a Harvard lecture hall, asking his students’ forgiveness as his professional life was unraveling. “Some of you will have seen my statement of regret, expressing my shame with respect to what I did in communication with Mr. Epstein," Summers said, according to a video taken by an attendee...