A Political Fable

[Fresco from West House, Thera, Minoan Crete, 15th c.
BC]
Whatever its basis, the Atlantis story is presented by Plato as a myth or moral fable about the human condition. It has a background in a war fought some decades before Plato's birth, when Athens took the lead in repulsing a Persian attack on Greece. Though far from fulfilling his political ideals, Athens had at least proved a city-state's superiority to an empire. That was a lesson on which Plato wanted to improve. Hence he pictured an ancient Athens that did resemble his own ideal republic, and foiled the aggression of an empire even greater than Persia. Atlantis as he evoked it owed some of its characteristics to Minoan Crete, ancient site of the legends of the Minotaur and Labyrinth: maritime rule, opulent palaces, warm baths, a bull-cult. But it is unlikely that Plato saw these as more than descriptive trappings for a huge alien power which he knew had never existed in the Mediterranean. It belonged outside the known world. The Greeks already had a mythic view of the outer Ocean, fascinated with the imagining of wonderful lands across it, the Isles of the Blest, for example, or the Garden of the Hesperides.
Whether or not Plato also adopted an Egyptian tradition
of 'land to the west', he had space and precedent in the Atlantic.
On an island larger than those earlier imagined, he built up the image
of an imperial federation, with a navy and dominion over lesser islands,
and portions of the continents both eastward and westward--the latter
possibly reflecting a vague awareness of the New World. This
was the Atlantis of Plato's conception. Since it was no longer there, at
least within the range of Greek seamanship, he had to explain why not.
He attributed its loss to a convulsion of nature, here again perhaps
taking a hint from the traditions of the Minoan world. The Aegean island
of Thera (Santorin) had been smashed by a tremendous eruption in
the fifteenth century BC, sounding the last decades of Crete's importance.