What does the law know and how does it know it? In the past twenty years, this question has been posed most often in connection with scientific evidence and expert testimony. This bias toward scientific knowledge shows the persistence of the ancient idea of natural law: that nature is the law’s ultimate, most persuasive source of legitimation.

Professor Sheila Jasanoff, Pforzheimer Professor of Science and Technology Studies at Harvard University's John F. Kennedy School of Government, argues that the law today is a powerful force for naturalizing; that is, for rendering natural the legal dispensations that we wish to live by. How does the law know what should be done; what in effect is just?