What was Chaos in Greek mythology?

The Muses on Helicon

Hesiod opens his Theogony, the poem of the gods’ birth, with a meeting. He was minding sheep on Mount Helicon when the Muses spoke to him, with a warning about stories: “We know how to speak many false things as though they were true; but we know, when we will, to utter true things.” Then he asks them to tell him “which of them first came to be” (Theogony 114–115). Their answer begins with a gap:

Verily at the first Chaos came to be, but next wide-bosomed Earth, the ever-sure foundations of all the deathless ones who hold the peaks of snowy Olympus

A gap, not a mess

The Greek word chaos comes from the same root as verbs for gaping and yawning, the root that also gives chasm. Hesiod’s Chaos is an opening: empty, dark space before anything stands in it. He never says what it is made of, and he never says that Earth came out of it. Chaos simply came to be first, and Earth came next.

The gap stays in the poem. During the war of the gods, the heat of Zeus’s lightning reaches even Chaos (Theogony 700), and the beaten Titans end up living “beyond gloomy Chaos” (814), at the dark bottom of the world. Centuries later, Aristotle read Hesiod’s first line as proof that things need a place before they can exist (Physics 4.1).

What came next

After Chaos, Hesiod lists Earth, the firm ground under the gods; dim Tartarus deep beneath her; and Eros, “fairest among the deathless gods,” who weakens the limbs and overrules the minds of gods and men alike (Theogony 116–122). Chaos then has children of its own: Erebus, the darkness under the earth, and black Night, who bears Aether, the bright upper air, and Day (123–125).

Earth, Gaia in Greek, does the rest. On her own she bears starry Sky, Uranus, “equal to herself, to cover her on every side” (126–127), then the hills and the sea. With Sky she has the Titans, the Cyclopes and the Hundred-Handers, the family whose quarrels fill the rest of the poem (Titans and Olympians). Her name lives on in the Gaia hypothesis, James Lovelock’s picture, from the 1970s, of the Earth as one living system.

How chaos came to mean disorder

The change came through Rome. Ovid opens his Metamorphoses with a different Chaos, not an empty gap but a jumble of everything at once:

Before the ocean and the earth appeared, before the skies had overspread them all, the face of Nature in a vast expanse was naught but Chaos uniformly waste. It was a rude and undeveloped mass, that nothing made except a ponderous weight; and all discordant elements confused, were there congested in a shapeless heap.

Ovid’s god then sorts the heap into earth, sea and sky. Ovid was read in schools all over medieval and Renaissance Europe, and his heap, more than Hesiod’s gap, gave the word its modern sense of confusion. In the 1600s the Flemish chemist Jan Baptist van Helmont even built the word gas from it. Hesiod’s Chaos is older and stranger: not a mess waiting to be tidied, but room for a world to begin. Out of that beginning, in Hesiod, came the goddess of the foam, too.