Modified: 2023-12-28
Aristotle was an empiricist, meaning that he believed in collecting his own data. In fact, during the Middle Ages, Aristotle's entire body of work became the main source of knowledge for most people. Then, finding things out became a search through that work to see just what Aristotle had written about it.
Sir Francis Bacon told a story, perhaps apocryphal, that illustrated just how empiricism was lost during the Middle Ages. The story was that a meeting of monks was taking place and the monks were hotly debating the issue of how many teeth were in the mouth of a horse. The problem was that they could not find the answer anywhere in Aristotle's work. Then, a young monk, perhaps at his first such meeting, timidly suggested that, because they had all come to the meeting on horseback, that one way to get the answer would be simply to go outside and count. Bacon went on to say that the young monk was expelled from the meeting! That was not how research was conducted back then.
But, the story is illustrative of how empiricism can be replaced by other forms of knowledge seeking. Aristotle was an empiricist, but after he died others did not continue that empirical tradition, so the data that Aristotle had collected were not revised and updated. The data became old and stale, but that was not Aristotle's fault; you cannot collect data from the grave.
So, Aristotle gets some bad press today; the antiquity of his data is one reason, but, as we have seen, that was not his fault. The Catholic Church, by codifying his data as the one source of all earthly knowledge, gets the blame there. The Church compounded that problem by disallowing further new empirical data collection as well. On the other hand, Aristotle does deserve the bad press he gets for his belief in final causes.
For Aristotle, the existence of an object and its corresponding function was proof enough of its necessity. For example, the fact that this page is teaching you psychology is the proof of why it was manufactured in the first place. In other words, you are learning psychology from this page, the page is teaching you; therefore, the page was created to teach you psychology. That is the logic of final causes.
So, today science believes in efficient causes, not final causes. Further, science works by what we call parsimony. Your spouse or your significant other may be parsimonious, a nice word for being cheap. In science, we are cheap also. But, we are cheap not with money, but with our explanations. The less explaining you have to do, the better. For example, both Copernicus's heliocentric model and Ptolemy's geocentric model explained the motion of the planets, and predicted eclipses and the tides, but Copernicus's model was much simpler. The orbits of the planets were circles, not the complex epicycles that Ptolemy had to resort to because he had the Earth in the center of the universe. So, long before we could directly observe the solar system, we had adopted Copernicus's model because it was simpler and explained the data just as well as Ptolemy's model.
For us, Aristotle serves as a foil and backdrop for modern science. On the one hand Aristotle was an empiricist, and modern science is empirical as well. But, Aristotle was a believer in final causes, and thus exhibited teleological thinking. Modern science has dismissed such thinking, and has incorporated parsimony instead.