“Ultimately...woman's equality is not derived from any theory of human nature but rather from concepts of justice, equality and the integrity of the individual based on philosophical and political principles that we have evolved since the Enlightenment. "There is, in fact, no incompatibility between the principles of feminism and the possibility that men and women are not psychologically identical,' writes Pinker. 'To repeat: equality is not the empirical claim that all groups of humans are interchangeable; it is the moral principle that individuals should not be judged or constrained by the average properties of their group.”