Natural place

Use in the book

Aëtius says the elements’ places are neither permanently fixed nor determined, because all take one another’s places. Achilles illustrates the point through earth moving aloft and fire occupying a lower position. The account describes more than the ordinary sorting of heavy below light: it allows the constituents to exchange positions.

This matters when reading the cosmic formation reports. A central mass of earth at A49 or an outer fiery hemisphere at A30 is a location within a particular arrangement, not necessarily an eternal rule prescribing where every portion of that root must always be. The testimonia need not contradict one another simply because they describe a sorted world and also deny unchangeable elemental stations.

The word nevertheless belongs to the reporters’ explanatory prose. Their comparison with fixed places may reflect later cosmological debates. The passage should not be turned into a complete doctrine of homogeneous space, absolute mobility, or the absence of all directional tendencies; none of those larger conclusions is stated.

Places to read

1. A 35 (testimony)Aëtius II 7,6. Denies permanently fixed places and makes elements take one another’s positions.
2. A 35 (testimony)Achilles, Isagoge 4. Illustrates exchange of positions by earth aloft and fire lower down.
3. A 70 (polemical)2Aristotle, On the Soul. Attributes downward growth of roots to earth’s natural downward travel and upward growth to fire, complicating a blanket denial of directional tendencies.

Translation in this edition

The edition notes that Aëtius’ chapter concerns cosmic order. That arrangement does not invalidate the elemental content, but it reminds the reader that a doxographic heading can frame how a report is read.