PROBABILISTIC IMPERIALISM

The empire of chance began with an unsteady foothold in gambling problems some three hundred years ago and now sprawls over whole conceptual continents. All of the natural and social sciences belong to its territories, and there have been conquests – cliometrics, statistical comparisons of literary style – even in the humanities. It also encompasses important parts of law, medicine, industry, and practical economics, and, in its descriptive statistical aspect, has breached almost every wall. Insofar as we listen to weather reports, ponder political polls, undergo medical tests, pursue the sciences, plot the standard of living index, buy insurance, or even read the newspaper, we are all its subjects.

In these pages we have followed the steady and occasionally explosive growth of this empire as probability theory and statistics evolved as mathematical disciplines and at the same time acquired ever more diverse applications. These developments of course went hand-in-hand, but the mere existence of a new mathematical technique was not sufficient in itself to win the theory new applications. Here interpretation and analogy played critical roles, as we have seen. Whether probability was interpreted as a degree of certainty, as a relative frequency, as a propensity, or in some other way, determined the plausibility of particular applications, be they to evaluations of legal evidence or to life insurance.