Science Friction_ Where the Known Meets the Unknown - Michael Shermer [81]
As a model of history (not a law), contingent-necessity provides a general cognitive framework for representing historical phenomena that does what the philosopher of science Rom Harré requires for models to be useful by distinguishing between the source and subject of a model: “The subject is, of course, whatever it is that the model represents. . . . The source is whatever it is the model is based upon.”13 When subject and source are the same, Harré calls these models homeomorphs; when different, paramorphs. A model airplane that represents both airplanes and a particular model of an airplane is a homeomorph model since source and subject are the same. Charles Darwin’s model of the tree of life is a paramorph model since source and subject are different. The model of contingent-necessity is a paramorph model because, while as a general framework it may describe specific historical subjects, its source is not any one particular subject. Since the model attempts to explain a wide variety of historical examples, its source and subject are different.
As a historical sequence, the model of contingent-necessity is limited in its analysis to a specified range of chronological margins that are chosen by the historian. In other words, a historical sequence is what the historian says it is. The variables, however, are not arbitrarily chosen. The historian can present evidence for the significance of these precise starting and stopping points, which is what we already do. Once these chronological boundaries are established, then the model of contingent-necessity and its corollaries can be used as a heuristic framework for representing what happened between these limiting termini. A historical sequence is a time frame determined by the focal point and the boundaries of the subject under investigation.
Contingent-necessity and chaos are not dissimilar. At the 1986 Royal Society of London conference on chaos, Ian Stewart reports that scientists devised this seemingly paradoxical definition of chaos: “Stochastic behaviour occurring in a deterministic system.” Stewart notes that since “stochastic behaviour is . . . lawless and irregular,” and “deterministic behaviour is rule by exact and unbreakable law,” then “chaos is ‘lawless behaviour governed entirely by law,’” an obvious contradiction.14 When chaos scientists use the word, however, they do not mean actual lawless and random behavior; they mean apparent chaos. The order is hidden from view by traditional methods of looking (e.g., linear mathematics). The apparently chaotic actions of the phenomena exhibit an interaction between the small, contingent events of a sequence and the large, necessitating laws of nature. When looked at in the light of contingent-necessity, it becomes possible to see that this is not a paradoxical usage and the following definition may be made: Chaos is a conjuncture of events compelled to a certain course of action by constraining prior conditions. Thus, “stochastic behaviour occurring in a deterministic system” is a similar description to “a conjuncture of events compelled to a certain course of action by constraining prior conditions.” Chaos and contingent-necessity model phenomena in the same manner, as Ilya Prigogine notes when observing that in chaos the “mixture of necessity and chance constitutes the history of the system.”15 In like manner, necessity and contingency are the shaping forces for historical sequences. If this correspondence between chaos and contingent-necessity exists, then we can draw certain analogies between physical and biological chaotic phenomena and human historical ones.
According to Prigogine, all systems, including historical