This book aims to investigate the philosophical foundations of Hans J. Morgenthau''s project of Political Realism. It argues that a fundamental goal spanning Morgenthau''s political realism is to critique scientism in politics and to present a viable "unscientific" alternative with which to properly understand and practice politics. Morgenthau rejects the possibility of modeling political science on the natural sciences, through modern scientific method. This rejection of scientific politics rests on a more basic critical analysis of the possibility of a scientific understanding of both human nature and ethics. Beyond this, Morgenthau''s positive and rational, yet unscientific, contribution to politics is outlined in the hope both to provide both a better understanding of what is actually knowable and possible in politics as well as to provide a direction for future research.