The Beginning of Infinity

"The thought to which Deutsch’s conversation most often returns is that the European Enlightenment of the 17th and 18th centuries, or something like it, may turn out to have been the pivotal event not merely of the history of the West, or of human beings, or of the earth, but (literally, physically) of the universe as a whole.

Here’s the sort of thing he has in mind: The topographical shape and the material constitution of the upper surface of the island of Manhattan, as it exists today, is much less a matter of geology than it is of economics and politics and human psychology. The effects of geological forces were trumped (you might say) by other forces — forces that proved themselves, in the fullness of time, physically stronger. Deutsch thinks the same thing must in the long run be true of the universe as a whole. Stuff like gravitation and dark energy are the sorts of things that determine the shape of the cosmos only in its earliest, and most parochial, and least interesting stages. The rest is going to be a matter of our own intentional doing, or at any rate it’s going to be a matter of the intentional doings of what Deutsch calls “people,” by which he means not only human beings, and not all human beings, but whatever creatures, from whatever planets, in whatever circumstances, may have managed to absorb the lessons of the Scientific Revolution.

There is a famous collection of arguments from the pioneering days of computer science to the effect that any device able to carry out every one of the entries on a certain relatively short list of elementary logical operations could, in some finite number of steps, calculate the value of any mathematical function that is calculable at all. Devices like that are called “universal computers.” And what interests Deutsch about these arguments is that they imply that there is a certain definite point, a certain definite moment, in the course of acquiring the capacity to perform more and more of the operations on that list, when such a machine will abruptly become as good a calculator as anything, in principle, can be.

Deutsch thinks that such “jumps to universality” must occur not only in the capacity to calculate things, but also in the capacity to understand things, and in the closely related capacity to make things happen. And he thinks that it was precisely such a threshold that was crossed with the invention of the scientific method. There were plenty of things we humans could do, of course, prior to the invention of that method: agriculture, or the domestication of animals, or the design of sundials, or the construction of pyramids. But all of a sudden, with the introduction of that particular habit of concocting and evaluating new hypotheses, there was a sense in which we could do anything. The capacities of a community that has mastered that method to survive, and to learn, and to remake the world according to its inclinations, are (in the long run) literally, mathematically, infinite. And Deutsch is convinced that the tendency of the world to give rise to such communities, more than, say, the force of gravitation, or the second law of thermodynamics, or even the phenomenon of death, is what ultimately gives the world its shape, and what constitutes the genuine essence of nature."