This fellow is the president of Harvard University, which is an educational and research institution, where research is carried out that sometimes makes it possible for people to know what they are talking about. Unless, of course, the people in question are blissfully unacquainted with that research. That might be why Lawrence Summers decided to tell a conference on diversity in science and engineering that the reasons for the low representation of women in the area have to do with them being unwilling to work hard enough and not being biologically disposed to understand mathematics. No transcript is available, since Dr Summers apparently decided to blither off the cuff.
According to the New York Times, Dr Summers has two explanations for his concerted campaign to demolish the prestige of the institution which employs him. One is that "I wanted to add some provocation to what I understand to be basically a social science discussion," which he certainly did, demonstrating that provocation attracts a good deal more media attention than social science.
His other other explanation is "I'm sorry for any misunderstanding but believe that raising questions, discussing multiple factors that may explain a difficult problem, and seeking to understand how they interrelate is vitally important." But there is no misunderstanding: the conference participants may well have been raising questions, discussing factors and seeking to understand, but Dr Summers was not.
Also: Do take a peek at the responses by Prof. PZ Myers, by the pseudonymous Professor B, and by Matt Yglesias.