In this concluding volume in the trilogy that begins with "On Power" and moves to "Sovereignty," Bertrand de Jouvenel proposes to remedy a serious deficiency in political science, namely, "the lack of agreement on first principles, or 'elements.'" The author's concern is with political processes as they actually exist, not as they are conjectured to be in hypothetical models. As an indication of the originality and imaginativeness that Jouvenel brings to his task, the sections explore "Politics as History," "Setting: Ego in Otherdom," "Action: Instigation and Response," "Authority: 'Potestas' and 'Potentia, '" "Decisions," and "Attitudes." Jouvenel draws richly upon the "drama of politics" as it is portrayed in the works of Thucydides and Shakespeare.Bertrand de Jouvenel (1903-1987) was a renowned observer of British and American institutions.Daniel J. Mahoney is Associate Professor of Politics at Assumption College.