I think whatshisface is being overly dismissive of the value/information in ancient philosophy. But the heart of his comment is that you can cherry pick pretty much whatever you want from ancient philosophy because the corpus is so large. If you, e.g., selectively choose statements that vaguely line up with quantum mechanics, you haven’t proven that Ancient Greeks knew quantum mechanics or had some unexpectedly deep understanding of the universe. You did something equivalent to P-hacking to dig meaningless correlations out of the noise.

Right, it would be inappropriate to claim that Plato predicted the big bang!

He did arguably explicitly predict that basic mathematical/geometric forms underlie the structure of the universe. E.g., that atoms would be composed of pyramids, cubes, dodecahedrons and that the behaviour of atoms would be based upon the different geometric properties of basic forms.

That idea is only partially correct, however. Atoms are based on the basic mathematical forms -- but on the spherical harmonics of electron clouds, not point geometries. Whoops! Otherwise, the idea is commensurable with modern atomic understanding.

Earth, water, air and fire correspond not to elements (ice can melt, obviously) but to phases of matter. (Solid, liquid, gas, plasma).

There is a reason Classical Greek philosophy underlies western civilization. They were not dummies and there is still a lot we can learn from them. It's not like all their ideas were examined in the 1800s and we took all the good ones, leaving the classics as a sort of intellectual skin worth shedding. Instead, it is the core we build on. It's worth understanding the core -- and giving them the benefit of the doubt to identify interesting ideas.

Like that the universe begins with "the one" :)

That is some impressively hand-wavy equivalency. Plato predicted something pretty much entirely wrong and you're pretending he was generally correct. Plato believed, without evidence, that there were some indivisible units of matter. That's all he got right (and even that was arguably incorrect given subatomic particles).

>If your argument was extended from 'ancient philosophy' to 'anything ever said by humans', then anything ever said by humans would fill the sentence space fairly uniformly, so finding out that anyone has said anything doesn't help.

That's accurate, though. If I told you a statement and backed it up with the claim that "at some point in history, a human said it" then you really haven't learned very much. Likewise, if a statement is tagged with "and by the way, an ancient philosopher believed it," you may have learned something about history, but the statement itself hasn't gotten any more believable.