Two dialogues, one story
Everything that survives from antiquity about Atlantis in detail comes from two dialogues by Plato, the Timaeus and the Critias, probably written in the 360s or 350s BCE, late in his career. They are linked: the Timaeus begins the story and the Critias continues it. Reading them directly is the best way to separate what Plato said from what later writers added.
Both dialogues are presented as a conversation the day after the discussion recorded in the Republic, about an ideal city. The speakers include Socrates, Timaeus (a philosopher from southern Italy), Critias and Hermocrates. Socrates asks the others to show his ideal city in action, in a conflict with another state, and Critias offers a story he says is true.
How the story is framed
The Timaeus introduces the account through layers of retelling. Critias says he heard it as a boy from his grandfather, also named Critias, who was then very old. The grandfather heard it from Solon, the Athenian lawgiver whose Solon reforms date to the early sixth century BCE. Solon, in turn, learned it from priests at Sais in Egypt, who told him that Greeks were always like children because they had no old records. The priests said that Athens, nine thousand years earlier, had been the most excellent city and that its deeds had been recorded in Egyptian temples.
This structure is worth noticing. It lends the story an air of ancient authority, but it also makes it impossible to check. A reader cannot verify the chain, and Plato’s other dialogues use similar devices for myths he wants to present as thought-provoking. Critias insists that the account is “true”, and scholars debate how seriously that word should be taken.
What the Timaeus says
In the Timaeus, the Egyptian priest describes a great power that came from the Atlantic Ocean, beyond the Pillars of Heracles (the entrance to the Mediterranean), and attacked the lands within. The island, called Atlantis, was said to be larger than Libya and Asia put together. Its rulers held sway over parts of Europe and Libya as far as Egypt and Tyrrhenia, that is, Italy.
Athens, the account says, led the Greeks in resisting and then fought alone when the others dropped away. It defeated the invaders and freed those enslaved. Later, great earthquakes and floods struck. In a single terrible day and night the Athenian warriors were swallowed by the earth and Atlantis sank beneath the sea. The priest adds that the sea there is still impassable because of mud left by the sunken island.
That is all the Timaeus says about Atlantis. The rest of the dialogue turns to a very different subject, the creation and structure of the universe.
What the Critias adds
The Critias provides the detail that most readers remember, but it is unfinished. It begins with a description of ancient Athens and its social order, which resembles the guardian class of the Republic. It then describes Atlantis.
According to the text, the island was allotted to Poseidon, who fathered ten sons by a mortal woman, Cleito, and divided the land among them. The eldest, Atlas, gave his name to the island and the surrounding sea. The central plain was rich, and the capital was built on a hill with alternating rings of water and land, linked by canals and bridges. The buildings were decorated with metals, including one Plato calls orichalcum, which is described as shining like fire and valued next to gold. What the orichalcum alloy of later Greek and Roman writers actually was is still debated. A temple of Poseidon stood at the centre.
The people were at first virtuous and uninterested in luxury, since they kept to divine nature within them. Over time, the divine portion faded and human character prevailed. Plato then says that they became filled with greed and power, and Zeus decided to punish them.
At this point, the Critias stops mid-sentence. Whether Plato left it unfinished by choice, died before completing it, or abandoned the plan is unknown. A third dialogue, the Hermocrates, may have been planned and was never written. The consequence is that we have no account in Plato’s own words of the war itself in detail or the actual destruction as the Critias would have narrated it.
Why did Plato tell it?
Interpretations vary, but most scholars agree on a few points. The story is introduced to test Plato’s political ideal. Athens is shown as a disciplined, modest state that triumphs over an arrogant imperial power. Plato was critical of the real Athenian democracy of his day, so the Athens of the tale is an idealised city, not a historical portrait. The contrast is moral and political: self-restraint against excess.
Some readers see a link to Plato’s own time. In the late fifth century, Athens had built a sea empire funded partly by Delian League tribute and had suffered disaster in Sicily, and Plato may have been thinking of the dangers of naval imperialism. Others stress the philosophical theme that human institutions, however splendid, are subject to decay and natural catastrophe. Several scholars also note that Plato elsewhere composes myths to illustrate arguments, such as the myth of Er in the Republic, which suggests that Atlantis belongs in that tradition.
Whether Plato invented the whole story or used older material remains uncertain. There is no earlier Greek source, and the details look carefully designed.
Reading with care
A close reading shows how little the text supports many modern claims. Plato does not say Atlantis was technologically advanced in a modern sense, does not describe it as a source of wisdom for other civilisations and gives no precise location. The ideas that it was a continent in the mid-Atlantic, or a mother culture, come from later writers. Careful attention to the dialogues is therefore the best defence against most popular claims about the subject.