Following the ancient Greeks, I contend that appetite, spirit and reason are fundamental drives, each seeking its own ends. Existing paradigms of international relations are nested in appetite (Marxism, liberalism) or fear (realism). The spirit – what the Greeks often called thumos – had not until recently generated a paradigm of politics, although Machiavelli and Rousseau recognized its potential to do so. Using Homer's Iliad as my guide, I constructed an ideal-type honor society in A Cultural Theory of International Relations and used it as a template to analyze the role of the spirit in international relations in the ancient and modern worlds. In this chapter, I provide a brief overview of the characteristics and tensions of spirit-based worlds and their implications for warfare. In this connection, I derive six propositions about the origins of war which I then test against a data set.

I limit myself to four underlying motives: appetite, spirit, reason and fear. Modern authorities have offered different descriptions of the psyche and human needs. Freud reduces all fundamental drives to appetite, and understands reason only in its most instrumental sense. Another prominent formulation is Abraham Maslow's hierarchy of needs, developed from his study of great people and what accounted for their accomplishments. More recently, psychologists have sought to subsume all human emotions to seven fundamental ones. Maslow's hierarchy of needs is conceptually confusing and rooted in a distinctly nineteenth-century understanding of human nature.