Theory and evidence about causal mechanisms, at some point (probably) long ago, reached the carrying capacity for integration into knowledge through expression in words alone. Causal mechanisms, through the implementation of systemism in the discipline of international relations, need clarifying. Systemism is used to convey and analyze the contents of a primary source, Causes of War, by Jack Levy and William Thompson. Explaining war is the most long-standing empirical problem, in the sense of Laudan, in the field of international relations. (Laudan suggested, quite helpfully, a shift from empirical content to problem-solving ability for assessing theories with regard to scientific progress.) The diagrammatic approach from systemism is used to translate a narrative from Levy and Thompson into a series of figures that include causal mechanisms from respective areas of theorizing about the causes of war. The overall purpose of this exercise is to show how the approach from systemism possesses the potential to convey causal mechanisms in a way that facilitates scientific progress. All of this augurs well for a visual turn—toward approaches, such as systemism, that can help to more effectively assemble the massive amount of information now available into knowledge about international relations.
Systemism’s essence has been conveyed by its most long-standing exponent, Bunge: a commitment to building comprehensive theories. Systemism transcends reductionism and holism as the other available “coherent views” with respect to operation of a social system. Instead of theorizing at the level of the system (holism) or its components (reductionism), systemism allows for linkages operating at macro- and microlevels, along with back and forth between them. Systemism also includes inputs from, and outputs to, the environment. This comprehensive procedure facilitates the comparison of alternative visions regarding cause and effect. Thus systemism is an approach rather than a substantive theory. One of its distinguishing merits is a capacity to facilitate criticism and comparison of theories through their representation in diagrams that are constructed under a set of rules to convey causal mechanisms.