Plato's Cave And Platonic Essence

Writers of fiction refer to Plato:

Poul Anderson wrote "Plato's Cave";

Star Trek includes "Plato's Stepchildren";

CS Lewis described the mortal realm as "Shadowlands" (see below);

Lewis' Professor says that it is all in Plato (see here);

in Out Of The Silent Planet, Lewis fictitiously corresponds with Ransom about twelfth century Platonists;

SM Stirling's characters eat the "...Platonic essence of grilled steer..."
-SM Stirling, Shadows Of Falling Night (New York, 2014), CHAPTER FOURTEEN, p. 278.

Plato thought and taught that:

Ideas, like Goodness and Beauty, are perfect eternal realities because they are unchanged whenever we contemplate them;

transient instances of goodness and beauty are imperfect imitations of the corresponding Ideas;

sensory organs perceiving these imperfect imitations are like men seeing shadows on the wall of a cave and mistaking them for realities;

immortal intellectual souls contemplate Ideas between incarnations and are reminded of them by their sensory imitations.

My Comments
Reality is concrete, not abstract, whereas ideas are abstractions.
Philosophy, standing on its head, needed to be turned onto its feet.
When I ate a banana in Elba, I thought that every banana that I had ever eaten had tried and failed to imitate this perfect Banana.
Lewis thought that Heaven would contain Platonic essences that were concrete, not abstract, like that Elban Banana. (Excellent, if possible.)