“Already in Plato, as in Pythagoras before him, there appeared a veneration for the ancient wisdom of the Egyptians. Aristotle was more skeptical, and when he came to recount the history of philosophy in the first book of the Metaphysics, he started directly with the Greeks.
Influenced by Aristotle, the Christian authors of the Middle Ages showed relatively little curiosity about ancient Egypt. References to this tradition can be found only in marginal alchemical texts like Picatrix.
Isidore of Seville shortly mentioned the Egyptians as the inventors of geometry and astronomy, and said that the original Hebrew letters became the basis for the Greek alphabet when Isis, queen of the Egyptians, found them and brought them back to her own country (Etymologiarum, I, iii, 5).
By contrast, one could put the Renaissance under the standard of what Baltrušaitis (1967) has called the “search for Isis.” Isis became thus the symbol for an Egypt regarded as the wellspring of original knowledge, and the inventor of a sacred scripture, capable of expressing the unfathomable reality of the divine.
The Neoplatonic revival, in which Ficino played the role of high priest, restored to Egypt its ancient primacy.
“The wise sages of Egypt [ . . . ] in order to designate things with wisdom do not use designs of letters, which develop into discourses and propositions, and which represent sounds and words; instead they use designs of images, each of which stands for a distinct thing; and it is these that they sculpt onto their temples. [ . . . ] Every incised sign is thus, at once, knowledge, wisdom, a real entity captured in one stroke.”
Iamblicus, in his De mysteriis aegyptiorum, said that the Egyptians, when they invented their symbols, imitating the nature of the universe and the creation of the gods, revealed occult intuitions by symbols.
The translation of the Corpus Hermeticum (which Ficino published alongside his translations of Iamblicus and other Neoplatonic texts) was under the sign of Egypt, because, for Ficino, the ancient Egyptian wisdom came from Hermes Trismegistus.”
Umberto Eco, The Search for the Perfect Language, translated by James Fentress, Blackwell. Oxford, 1995, pp. 144-5.