How We Believe_ Science and the Search for God - Michael Shermer [137]
For the next century historians sought out those transmitted circumstances in the form of historical “laws,” culminating in 1942 with the publication of Carl Hempel’s influential paper entitled “The Function of General Laws in History,” in which he concluded: “There is no difference between history and the natural sciences: both can give an account of their subject matter only in terms of general concepts, and history can ‘grasp the unique individuality’ of its objects of study no more and no less than can physics or chemistry.” Hempel was wrong about general laws, but right about history and the natural sciences; not, however, in the direction one might think. History is not governed by Hempel’s laws (which he describes as “universal conditional forms”), but neither are the physical and biological worlds to the extent we have been led to believe. Scientists are coming to realize that the Newtonian clockwork universe is filled with contingencies, catastrophes, and chaos, making precise predictions of all but the simplest physical systems virtually impossible. As noted, we could predict precisely when and where Comet Shoemaker-Levy 9 would hit Jupiter, but we could muster at best only a wild guess as to the effects of the impacts on the Jovian world. The guess was completely wrong. Why? Contingency.
There is irony in Hempel’s quest for general laws in history. For decades historians chased scientists in quest of universal laws, but gave up and returned to narratives filled with capricious, contingent, and unpredictable elements that make up the past. Meanwhile, a handful of scientists, instead of chasing the elusive universal form, began to write the equivalent of scientific narratives of systems’ histories, integrating historical contingencies with nature’s necessities, as Gould observes: “This essential tension between the influence of individuals and the power of predictable forces has been well appreciated by historians, but remains foreign to the thoughts and procedures of most scientists.” Indeed, contingency is not Gould’s idea at all. Twenty-five hundred years ago Aristotle explained “that which cannot be otherwise is necessarily as it is,” yet “an event might just as easily not happen as happen.” and this is contingency. In a sense, science has been one long struggle to tame the contingent beast by finding necessitating laws that govern nature. Contingency becomes dangerous in Gould’s hands because he is a scientist, demonstrating how even a subject as predictable and subservient to natural law as planets and their moons, when examined closely, reveal so much uniqueness and individuality that while “we anticipated greater regularity … the surfaces of planets and moons cannot be predicted from a few general rules. To understand planetary surfaces, we must learn the particular history of each body as an individual object—the story of its collisions and catastrophes, more than its steady accumulations; in other words, its unpredictable single jolts more than its daily operations under nature’s laws.” Simply put, history matters.
Historians and philosophers have been cognizant for millennia of this basic tension between what may not be at all and what cannot be otherwise, between the particular and the universal, between history and nature, between contingency and necessity. But such synonyms can only take us so far (and may lead to problems of meaning and emphasis). Precise definitions are needed to formulate a model of change. Thus in this analysis contingency will be taken to mean a conjuncture of events occurring without design, and necessity to mean constraining circumstances compelling a certain course of action. Contingencies are the sometimes small, apparently insignificant, and usually unexpected events of life—the kingdom hangs in the balance awaiting