The Boundless (apeiron)
The principle cannot be any determinate element, or it could not generate its opposite. It must be infinite and indeterminate.
Ancient Greece & Rome · c. 610–546 BCE
Anaximander
阿那克西曼德 · Ἀναξίμανδρος
Proposed the Boundless as first principle, drew the first world map, and guessed that life began in the sea.
Milesian SchoolBirthplace: Miletus
Into that from which things take their rise they pass away once more, as is ordained.
Source: Simplicius, Physics 24.13
Anaximander was a younger fellow-citizen of Thales and reportedly his student. He wrote a prose work On Nature, the earliest Greek philosophical book, of which one quoted sentence survives. He also drew a map of the known world, built a sundial, and described the heavens with a geometrical model: the earth is a cylinder suspended at the centre of the cosmos, held up by nothing, because it is equidistant from everything.
He rejected Thales' water. If water were the principle, why has fire not been extinguished by it? The principle must be something with no determinate quality at all, which he called the apeiron, the Boundless. Opposites separate out of it: hot and cold, dry and wet encroach on one another and pay each other back according to the ordinance of time.
He also offered the first evolutionary guess: the earliest creatures lived in water, wrapped in prickly shells, and humans developed from fish-like animals, since human infants are too helpless to have survived in their present form from the beginning.
Key Ideas
The justice of opposites
Things encroach on one another and 'pay penalty for their injustice according to the ordinance of time'. Cosmic order is understood as legal order.
The unsupported earth
The earth needs no support because it sits at the centre, equidistant from everything. The first argument from symmetry in place of physical support.