The paper purports to argue for the radical realistic orientation of Hans Kelsen's Pure Theory of Law. Two arguments are provided: the wholesale argument from realism and the retail argument from Kelsen's theory of legal knowledge. The wholesale argument focusses on the many points where the epistemological and theoretical outlooks of the pure theory of law appear to be in tune with the basic claim characterizing realistic juris¬prudence. The retail argument provides a reconstruction of Kelsen's view about legal theory and scientific doctrinal study of law, emphasizing its overall commitment to an empirical legal theory and legal science.