CONTRIBUTIONS OF A WORKSHOP ON NEW SCHOLARSHIP IN INTERNATIONAL PUBLIC AND PRIVATE LAW, ORGANIZED BY THE AAA AND THE EUROPEAN LAW RESEARCH CENTRE OF HARVARD LAW SCHOOL, THE HAGUE, 22-23 JULY 2000 - E RETHINKING DOCTRINES OF PUBLIC INTERNATIONAL LAW - E.2 Speech Act Theory and the Concept of Sovereignty; A Critique of the Descriptivistic and the Normativistic Fallacy