Larry Summers, the President of Harvard, has come under fire from feminists for suggesting that women have not excelled as well as men in science and engineering because of inferior intrinsic aptitude, among other reasons. Now, no one denies that women are different physically from men, and it is clear that those physical differences can affect how the sexes behave; it is not disputed that men in general are physically more aggressive than women because of stronger upper body strength and the influx of testosterone. Where Summers got into trouble, however, was declaring as if it were a fact that...