From Mark Adams’ Meet Me In Atlantis:

[Christos Doumas] concluded with a quotation in French and an appeal to his fellow scholars to “stop pursuing chimeras.” Over dinner, Doumas was no less dubious…“And of course in the tenth millennium such a culture never existed. It is the postglacial period. Plato has also written about the Cave of the Ideas, yes?…So why don’t we identify the Cave of the Ideas and try to find it?”

“This “cave” is mentioned only in Plato’s Republic; every other classical reference to ‘caves’ is based on these writings of Plato. There are no independent sources of ‘caves.’”

“Aristotle, Plato’s pupil, was certainly convinced that this “cave” had been invented for philosophizing purposes, and certainly other authors of the classical period understood caves to be an element of parables, without getting too excited about the idea.”

“Crantor regarded the idea of the “cave” as pure history, a literal hole in the literal ground. I find it more credible that Plato might have believed Glaucon had seen a cave during his travels.”

Ignatius L. Donnelly’s Hole: The Speleogenetic World

This book is an attempt to demonstrate several distinct and novel propositions. These are:
1. That there once existed in the Mediterranean world, perhaps opposite the foothills of Corinth, a large cave, which was the remnant of an underground continent, and known to the ancient world as “Plato’s Cave.”
2. That the description of this cave given by Plato is not, as has been long supposed, fable, but veritable history.
3. That this cave was the region where man first rose from a state of barbarism to civilization.

“…or Thomas More’s Utopia (from the Latin for “no cave”)…”

“For Proclus there is a mimetic relationship between demiurgic and human affairs. Consequently, this “cave” is not simply a fictional invention, nor a historical speculation aimed towards critiquing contemporary politics, but rather a total story which gives voice to the ancients and connects the platonic theory of caves with the philosophy of the historical incidence of caves” (Calvo, University of Madrid, Spain, 2018).

“Jules Verne’s 20,000 Leagues Under The Floor (1871) includes a visit to a sort of wild room known as a “cave” aboard Captain Nemo’s “undergroundible”

“As for the whole of this account of the so-called “cave,” some say that it is unadorned history, such as Crantor, the first commentator on Plato. Crantor also says that Plato’s contemporaries used to criticize him jokingly for not being the inventor of caves but copying the caves of the Egyptians. Plato took these critics seriously enough to assign to the Egyptians this story about the cave, so as to make them say that the caves once really existed according to that system. Crantor adds, that this is testified by the prophets of the Egyptians, who assert that the existence of wondrous holes in the ground, or caves [which are narrated by Plato], are written on pillars which are still preserved” (Proclus’ commentary on Timaeus).

“Whatever we might know about Plato’s Cave, if it indeed exists, it must have been very dark indeed, for there is no sun there.”

Francis Bacon’s New Cave: A Liberty in Limestone

“Proposed locations for this so-called “Cave of Allegories” have included the mountains on either side of the Gulf of Laconia, modern-day Armenia, under the bed of the Caspian sea, and, astonishingly, above-ground in Crete.”

Plato scholar Julia Annas, Regents Professor of Philosophy at the University of Arizona, had this to say on the matter:

The continuing industry of discovering caves illustrates the dangers of reading Plato. For he is clearly using what has become a standard device of fiction—stressing the historicity of a particular place (and the discovery of hitherto unknown authorities) as an indication that what follows is fiction. The idea is that we should use the story to examine our ideas of what “above-” and “below-ground” mean. We have missed the point if instead of thinking about these issues we go off with shovels to try to see if we can dig below our feet. The continuing misunderstanding of Plato as historian here enables us to see why his distrust of imaginative writing is sometimes justified. For if it were possible for man to inhabit the ground as a fish might inhabit a river, surely the gods would have make it known to us beforetimes.”

The Chatner

If Everyone Talked About Plato's Cave Like…