It is a special characteristic of the modern Western world, as opposed to other civilizations and the premodern Western world, to believe that human beings can change and control the physical and social environment and even human nature to improve the condition of life.—Donald Kagan
Kagan’s book On the Origins of War grew out of a series of lectures in comparative history drawing parallels between the Peloponnesian War and the First World War, and between the Punic Wars and the Second World War. He states that humanity is at war more often than it is at peace and that this state of affairs was universally accepted until the eighteenth century when many began to optimistically prophesy a new dawn of social tranquility. Such was the view of radical republicans like Joseph Priestly, Thomas Paine, and Immanuel Kant. Interestingly this optimism was also espoused by many free trade advocates (e.g., Richard Cobden and John Stuart Mill) who believed that unrestricted commerce would bring down barriers and emphasize human interdependence. The same hopes are still with us.
It is interesting that Kagan highlights a divergent strain in early free market thought that is often overlooked. While Adam Smith operated along traditional ethical lines, many later “capitalistic” thinkers embraced programs that were “liberal” both economically and philosophically. For them, the free market was less a matter of empirically observable economic behavior (Smith and Hayek) than a positive “force” for unlimited social or individual perfection. An analogous situation exists in democratic thought. Some have viewed democracy in a restrained manner (Cooper and Tocqueville) and others more progressively (Dewey).
While Kagan attempts to draw out limited generalizations and patterns from the historical narrative, he criticizes those who “expect to find the one big trick that will explain everything.” I think that would have to include certain strains of modern libertarianism, insofar as they embrace a utopian outlook. It does not matter whether that idealism is collectivist or individualist since it distorts our understanding of human actions and consequences. From a reading of history it becomes very clear that our decisions are not motivated solely by market factors. Even economic choices can be dictated (often irrationally) by non-economic considerations. Kagan points to things like “honor” and “fear” that can be as powerful as mere self-interest. We may dislike this and hope that a true market system will mitigate human vagaries, but it cannot eliminate the basic fact of our nature which frequently leads to military conflict.