Is the God of Our Fathers a Physicist or a Botanist?

When it turned out that there were not just three elementary particles—electrons, protons, and neutrons—but an array of smaller ones seeming to fit no system, Enrico Fermi allegedly remarked, “If I had wanted to remember the names of seventeen particles, I would have become a botanist.”

This comment, which has also been attributed to Albert Einstein, expresses a particular view of the universe that has been especially important in the history of physics: behind the apparent complexity of things, a few simple laws govern. Botanists multiply, physicists reduce. The Ptolemaic astronomical system posited a bewildering mélange of complex cycles and epicycles to account for the puzzling movement of the planets, which sometimes even switched direction and moved backward, but Newton replaced all that Ptolemaic machinery with four simple laws. It was the greatest scientific achievement in history. As Alexander Pope famously declared, “Nature and Nature’s laws lay hid in night:/ God said, Let Newton be!, and all was light.”

Newton’s laws became a model of truly scientific explanation. Since then, countless thinkers—whom Élie Halévy memorably called “moral Newtonians”—have tried to do for the social world what Newton did for the solar system. Surely all the complexity we see around us must follow some discoverable fundamental principles. Jeremy Bentham, Karl Marx, Sigmund Freud, B.F. Skinner—and more recently the behavioral economist Gary Becker and the popular historian Jared Diamond—along with many others have claimed to have discovered those simple principles. The fact that ever more such claimants, like the inventors of faddish diets, keep appearing is a sure sign that they have not succeeded.