The analogy of the sun (507b–509c)

Immediately before the cave: as the sun gives visible things both their visibility and their coming-to-be, so the Good gives intelligible things both their knowability and their being — and the Good itself is not being, but beyond being, exceeding it in dignity and power. Glaucon laughs at the extravagance of the claim, and Socrates tells him it is his own fault for asking.

The four most consequential words in this pack. Epekeina tēs ousias. Plotinus builds the One on them; Dionysius makes them a method; the Kabbalah receives them as a rule of speech about Ein Sof.