Recently read the book "Gravity" by George Gamow, in which he says:

For centuries Aristotelian philosophy and scholasticism dominated human thought. Scientific questions were answered by dialectic arguments (i.e. by just talking), and no attempt was made to check, by direct experiments, the correctness of the statements made.

I was wondering if there are any contemporary accounts of the realization of the horrendous mistake that was made, lamenting the wasted centuries of unquestioning acceptance of the Aristotlean view of science. I mean, weren't people of Galileo's time shocked at the thought that something so simple yet so wrong lay right beneath their noses for centuries?!

  • 4
    $\begingroup$ In part because it was not "so simple" at all ... If you try to row on a boat you will experience that when you stop rowing, after a little amount of time, the boat will stop moving. This mean that you need an "constant" force to produce movement. $\endgroup$ Apr 8, 2015 at 9:27
  • 1
    $\begingroup$ What "horrendous mistake?" People downplay Aristotelian physics nowadays, but it performed quite well in describing the kinds of motion people saw in their everyday lives. $\endgroup$ Apr 10, 2015 at 6:35

2 Answers 2


I would not call this "horrendous mistake", and I disagree with Conifold's statement that the reason was canonization by the Catholic Church.

It is easier to disprove Conifold's statement, so let me begin with this. Canonization of Aristotle begins at the times of Thomas Aquinas (13 century), AFTER 1000 years of the Dark Age, and about 200 years before the renaissance of science started. Actually incorporation of Aristotle into the official church teaching is considered a great progress by some historians (when compared with the Dark Age). Aristotle at least did not doubt that the Earth is spherical, as some Christian "scientists" did.

Second, the Muslim scientific thought was dominated by Aristotle, as much as the later Christian thought, since much earlier time, since its origin, and this has nothing to do with Christian church, of course. Let me add that Aristotle was dominating the thought already in the late antiquity, long before the introduction of Christianity in the Empire.

To answer the question itself is somewhat more difficult because OUR thought is dominated by something else, let me call it "Baconian tradition", I do not insist on the name, this is just a label.

The statements that scientific theories have to be verified by experiments and observations, and that this is the main criterion of truth, is FAR from being self-evident. It was actually a great discovery, made approximately in 16 century, and the precise formulation is associated with the name of Francis Bacon in the English-speaking world, at least.

I emphasize that this was a GREAT DISCOVERY, the thing which is hard to understand to modern people, because of the way we were educated. We tend to think that this is something self-evident.

But science, as we understand it now, really never existed before in this form. Of course there was some great science in antiquity but it was different. People THOUGHT differently from what we do. The true experimental science in the modern sense did not exist. (If you disagree, tell me of ONE true physical experiment described in ancient Greek or Roman books. I know only one, but a closer examination proves that this really was a "thought experiment" :-)

The modern period in science lasts less 400 years. Most of the time in history, in most of the places the idea that "experiment is the criterion of truth" would sound weird and incomprehensible. What we call "Dark Age" is more normal and typical than what we see in the last 400 years, from the point of view of the whole history.

Even at the times of Galileo, one could hear objections to what he said of the type: This cannot be true BECAUSE this contradicts Aristotle (or worse, contradicts the Scriptures). And some people refused to look in the telescope, saying that all these are "tricks" etc.

Even at this time there are people who would say this, that something contradicts the Scriptures, or Quran, or Engels, or whatever other authority, THEREFORE it cannot be true.

  • 1
    $\begingroup$ The "canonization" of Aristotle started in the Eastern Roman Empire (Byzantium) under Justinian (527-565) with serious consequences, as Philoponus's example shows. Even in the West it long predates Acquinas, whose role was to reconcile already established doctrines with newly discovered works of Aristotle from Arabic sources. In late antiquity Aristotle had to share the stage with Neoplatonics, Stoics and Epicureans, among others. Justinian ordered all philosophical schools in Athens closed in 529 AD. $\endgroup$
    – Conifold
    Apr 9, 2015 at 0:15
  • $\begingroup$ @Conifold: Thanks for this remark. I know very little about science in the Eastern empire (and even asked on this site, did not get interesting references). Could you give a reference on Philoponus? $\endgroup$ Apr 9, 2015 at 1:53
  • $\begingroup$ @Conifold: I wrote in my answer that "Aristotle dominated since the late antiquity". This includes the time of Justinian too. But what makes you think that he was somehow "canonized" by the Christian church at that time? $\endgroup$ Apr 9, 2015 at 1:55
  • $\begingroup$ @Conifold: The Wikipedia article on Philoponus does not give a slightest hint that Aristotle was "canonized" at that time. And it makes clear that Philoponus was prosecuted NOT because he criticized Aristotle, but for very different reason. $\endgroup$ Apr 9, 2015 at 6:34
  • $\begingroup$ Church fathers singled out Plato and Aristotle, Alexandrian school began the adaptation even before 476 AD, the "official" end of antiquity. Dialogue form wasn't seen as suitable for teaching, so Aristotle was most used and commented on, especially his Christianity "compatible" works like Organon. Even Plato was Aristotelianized, and he had no natural philosophy to speak of. After Justinian eliminated pagan competition (Philoponus abandoned philosophy c.530 AD) this school became dominant in Byzantium. $\endgroup$
    – Conifold
    Apr 9, 2015 at 17:46

The main reasons Aristotle dominated European thought for centuries were the canonization of his physics and cosmology by the Christian church, and the general decline of science and education in Europe. People were not shocked in part because acceptance of Aristotle's views was not based on their empirical merits. Scholasts and theologians, the learned of the time, were more interested in the internal coherence of the church's teachings, and especially their conformity with the scripture. Once Aristotle's natural philosophy was assimilated, rejecting it could be seen as a challenge to the church's authority, a risky move.

In addition to that, what is "simple" and "beneath your nose" is often in the eye of the beholder, and depends on a cultural context. Aristotle based his view of falling bodies on comparing a rock and a feather. Like many others in antiquity he rejected existence of a void, so Galileo's idea that air resistance should be "disregarded" was alien to them. For comparison, Babylonians, and even mathematically savvy astronomers like Hipparchus and Ptolemy, were using a zero placeholder symbol for centuries, but it never occurred to them to treat it as a number. It did to medieval Indians. Kepler mentioned that he did not initially consider ellipses when fitting the orbit of Mars because ellipses were known since antiquity, and he assumed that somebody tried them before him. Nobody did, it was all deferents and epicycles.

However, Aristotle's views did not go unquestioned for all those centuries. His theories of projectile motion, and of falling bodies were disputed already in antiquity, by Hipparchus (2nd century BC) and John Philoponus (6th century AD) among others. They originated an alternative theory of impetus, which became popular with Arabic scholars during middle ages, and in 14th century back in Europe. Philoponus rejected Aristotle's view and gave a modern account of falling bodies long before Galileo:

But this [view of Aristotle] is completely erroneous, and our view may be completely corroborated by actual observation more effectively than by any sort of verbal argument. For if you let fall from the same height two weights, one many times heavier than the other you will see that the ratio of the times required for the motion does not depend [solely] on the weights, but that the difference in time is very small.

Unfortunately, Philoponus happened to live in a wrong place (Byzantine empire) at a wrong time. For his trouble he was shunned by colleagues, his empirical bent and critique of Aristotle considered too radical, and forced to abandon philosophy for theology, where his views were declared heresy shortly after his death.

The final irony is that most historians believe now that Galileo's famous leaning tower of Pisa experiments never took place, they were thought experiments (possibly extracted from Philoponus or a later commentator). He reasoned the correct law of falling bodies out of a "sort of verbal argument" that Philoponus criticized Aristotle for. Perhaps, Galileo even thought that such an argument would be more convincing to people accustomed to Aristotle and scholasticism. But since such arguments can not possibly deduce empirical laws Galileo's had logical mistakes in it too. However, it was based on a much better empirical intuition and understanding of accelerated motion than Aristotle's, the insights not available to Hipparchus or Philoponus. Some of them developed earlier in Europe by Oresme and the Merton school.

  • $\begingroup$ The leaning tower experiment is most likely a legend. Galileo was a better experimenter than this legend suggests: he used inclined planes instead of simply dropping things. $\endgroup$ Apr 9, 2015 at 1:50
  • $\begingroup$ I do not see how you can talk of “the canonization of his (=Aristotle’s) physics and cosmology by the Christian church”. Aristotle taught that the world has no beginning, but has always existed in its present form. The Christians, like the Muslims and the Jews, rejected Aristotle’s cosmology and insisted that the world was created by God. $\endgroup$
    – fdb
    Apr 12, 2015 at 23:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.