Aristotle’s Science—Part 2

Aristotle had different scientific ideas than did his lesser-known contemporaries—and many of those ideas were simply wrong. He refuted Aristarchus, teaching that the Earth did not move and that the stars were permanent (the firmament). He badly misunderstood the motion of bodies and the influence of gravity. He taught that every body had a natural resting place and thus, for example, an arrow can keep flying only because the air it displaces moves behind the arrow and pushes it along. He essentially believed that scientific knowledge was complete at the time—that everything to be known about natural philosophy was in hand. He never put his scientific ideas to test by simple experiments, so they could not be proven wrong. The weight of their implied truthfulness, by the strength of his mind, carried the day.

Why did Aristotle’s erroneous scientific beliefs outshine and outlast the more accurate teachings of his Greek cohorts Herakleides and Aristarchus? Partly it was his gigantic reputation and partly the disciples who followed him. Aristotle founded the Lyceum, an academy that flourished for centuries and solidified his scientific ideas into rigid ideologies. Additionally, the Christian church later seized upon the Aristotelian dogma of an Earth-centered universe and added its weight to the belief. In contrast, Herakleides and Aristarchus were loners, whose more correct ideas died with them.

The result was that these erroneous Aristotelian scientific ideas got locked in for the next 1500 years. They held sway in Europe, into and through the Dark Ages—never getting challenged until Copernicus, Kepler, and Galileo began to rediscover and bring to light the truth. But all three of them paid the price for their teachings, as both the established scientific and Christian institutions’ doctrine that an unmoving Earth is at the center of it all had thoroughly ossified.

It makes me wonder how history might have been written, were it not for Aristotle’s dominant views of natural philosophy. How might things have unfolded if open inquiry into the physical nature of the cosmos had continued from Aristarchus? Copernicus, Kepler, and Galileo had to be extremely cautious about how they described their theories—lest the church lower its ecclesiastical boom. As it was, the first two deftly ducked, but Galileo got nailed.

It also shows that the history of science is not a logical, unfolding field of knowledge, which is tended by impartial, cool-headed people (sorry, Mr. Spock). It’s a lot more fascinating than that.