The Knowledge Machine: How Irrationality Created Modern Science

by Michael Strevens

Among the ancients there was no lack of desire to understand the workings of the world. Around 580 BCE, the Greek philosopher Thales gazed out from the port city of Miletus into the Aegean blue, into the summer haze where sea merges imperceptibly with sky, and proposed that everything is ultimately made of water. His student Anaximenes disagreed: the fundamental stuff, he said, is air. Heraclitus, who lived in Sicily a few decades later, suggested fire. Back in Miletus, Anaximander—another student of Thales about whom we know equally little—had meanwhile hypothesized that all things are composed of invisible stuff of unlimited potential that he called apeiron, or “the boundless.” Though these thinkers, their contemporaries, and their successors—Chinese scholars, Islamic doctors, medieval European monks—argued ingeniously for their points of view, no one of their ideas could gain a foothold over the others. Searching for the deep structure of nature, they contributed immeasurably to humanity’s stock of brilliant and original hypotheses, but to its stock of knowledge, scarcely at all. The reason is straightforward. Although premodern inquirers into nature sometimes hit on the right idea, they had little ability to distinguish it from its rivals.