Over the last few decades political scientists have shown an understandable interest in material brought into relief by neighboring disciplines. A concern with enriching the field of political science by drawing on sociological, economic, and psychological data has led to efforts to accommodate findings derived from study in areas in which men are subjected to non-political pressures—the constraints of society, the economy, and ultimately their own physical and psychological nature. As the conventional academic boundaries are crossed, knowledge of distinctively political matters, it has been hoped, will become richer as well as more precise. This essay seeks to clarify the promise and limits of two non-political approaches to an understanding of politics, namely those which are represented by two types of psychology, and to take account of their bearings on normative political thought.
Traditionally, normative political thought has been concerned with the analysis and understanding of the ends of political action: it has been an attempt to present and elucidate them. Setting specific points of view in a larger context, it has tended to be discursive and Utopian, speculatively enlarging the realm of public possibilities and common choices. More recently, it has been concerned with presenting models designed to assimilate empirically validated propositions about political behavior. To these concerns, various forms of non-political thought have always made their distinctive contributions.