Suppose that Socrates and Glaucon were to wake up and continue their dialogue on the nature of reality and the acquisition of knowledge, all in the light of modern scientific developments. Perhaps it would go something like this:

“Well, Glaucon, you must remember our previous discussion concerning the illusionary nature of the physical world and the attainment of true knowledge of the eternal Forms.”

“Yes, indeed I do – your Allegory of the Cave is truly unforgettable. Shall I summarize it for you?”

“Please do, Glaucon, so that we can perhaps re-interpret the metaphor after all these many years. In particular, given the predictive success of modern science and the resulting fascination with the physical world, we might discuss whether or not the allegory still contains a message for us.”

“As I recall, it goes like this: A group of prisoners sits in a cave; they are constrained to face a nearby wall and look at nothing else, and they have been in this position for all of their cogent lives. Behind them and above there is fire that dimly illuminates the cave, and between the fire and the prisoners there is a road on which puppeteers, hidden by a low wall, pass carrying various objects. Some of the objects are images of humans and animals; some are more abstract. The puppeteers are free to speak and their voices are reflected off the wall. The objects that they carry cast shadows on the wall, and the moving shadows and reflected voices are all that the prisoners can see or hear of the world; this forms their view of reality. The prisoners are permitted to speak with one another and discuss what they see. Of course, they assume that the images before them on the wall are the real world since this is all they know of it.”

“Excellent, Glaucon. Your memory is pretty good after 2500 years. And what happens next in the story?”

“We suppose that one of the prisoners is set loose and is forced to turn around – that is, away from the wall and into a position such that he can see the fire and what is happening behind the prisoners. His eyes are somewhat dazzled by the light of the fire and, at first, he cannot get a clear view of the forms passing along the road.