1. Many of Aristotle's scientific explanations are obviously wrong.
2. On the assumption that Greek science ended in the 4th century, Greek science had about 700 years to correct these obvious errors. But it didn't (in the sense that it did not arrive at a consensus of where Aristotle was wrong).
The first point is not simply that Aristotle was wrong. It was that he was obviously wrong. For example, he states in De Caelo (tr. Guthrie, Cambridge 1960 pp. 49-51) that if a weight falls a certain distance in a given time, a greater weight will move faster, with a speed proportional to its weight. This is obviously wrong: obvious in a way that his statement about why glass is transparent is not obviously wrong. To refute his theory about glass requires instrumentation and a complex atomic theory, neither of which was available to Aristotle. So while his transparency theory is wrong, it was not obviously wrong. But to refute his theory about falling bodies requires only a few simple experiments. In the 6th century A.D., loannes Philoponus challenged this as follows.
But this [i.e. Aristotle's theory] is completely erroneous, and our view may beSo my first point stands: some of Aristotle's scientific observations are obviously wrong, in a way that the technology and understanding of the time could easily have shown. On my second point, that Greek science did not correct these obvious mistakes, the history shows that clearly enough. You may object that Philoponus was Greek, and that he spotted at least one obvious error. I reply: Philoponus' observation does not amount to a scientific consensus. We make progress in science when we arrive at a view that is not necessarily correct, but which is accepted by a majority, or a significant majority, of the scientific community. This was not properly achieved until Galileo. And note also that Philoponus was writing somewhat later than Freeman's 'cutoff point' of 381 AD. Moreover, he was a Christian thinker.
corroborated by actual observation more effectively than by any sort of verbal
argument. For if you let fall from the same height two weights of which one is
many times as heavy as the other, you will see that the ratio of the times
required for the motion does not depend on the ratio of the weights, but that
the difference in time is a very small one." [M. R. Cohen and I. E. Drabkin, "A
Source Book in Greek Science" (McGraw Hill. N.Y.) 220 (1948) - my emphasis].