From the Beginning to Plato

THE IONIANS 45
notoriously claimed that sun, moon and stars were themselves bodies made of
compressed earth, fiery stones (Hippolytus Refutation 1.8.6 [KRS 502]), while
the atomists make them ignited complexes of atoms and void (Diogenes Laertius
IX. 3 2 [KRS 563]). However these later thinkers agreed in finding in the vortex
a mechanism to explain projected revolutions of these bodies, and so without
abandoning Anaximenes’ assumption (b) about downward motion could unlike
him account for their passing below the earth. 8
Another piece of information about Anaximenes’ views on the sun indicates
how he supported his thesis (c) that their flatness keeps flat things from falling: 9
‘Anaximenes says that the sun is flat like a leaf (Aetius II.22.1 [KRS 155]).
Floating leaves, of course, move about, just as Anaximenes’ sun does. Their
flatness prevents not lateral but downward movement. Why the sun, moon and
stars rotate but the earth does not is not discussed in the surviving evidence.
Now back to Thales: his reported view on the stability of the earth has to be
seen within the context of the general theoretical framework we have been
describing. Two features of the state of the evidence dictate this conclusion.
First, Aristotle’s citation of Thales’ idea comes in a chapter which represents him,
Anaximenes, Anaxagoras and Democritus as all upholding one side of the
argument in a pre-Socratic debate about the subject (Anaximenes’ ultimate
achievement is to have persuaded Aristotle that it was a key subject for the pre-
Socratics and his stance the standard one taken by them). Second, Thales himself
seems not to have written a book. So the likeliest way for his opinion to have
survived will be via a reference to it in the writings of someone close to him in
time: presumably either a member of his own circle such as Anaximander or
Anaximenes, or—as I shall be suggesting later—a critic such as Xenophanes. 10
To put the point a bit more sharply, we can perceive how Thales’ view about the
earth was received, both around his own time and in the pages of Aristotle, a lot
better than we can form reliable conjectures as to how it fitted into whatever
intellectual schemes he himself elaborated. In large part this is a function of the
elusiveness in history of the merely oral.
One guess might be that Thales had already anticipated Anaximenes in
conceiving of the earth and the sun, moon and stars as comparable phenomena
requiring to have their differing patterns of motion and stability explained by the
same sorts of physical mechanisms. At the other extreme he might be interpreted
as a figure much closer to the myth-tellers of the ancient Near East, preoccupied
as they were with the origin of the earth and its physical relationship with
primeval water, but not seeing a need to ask analogous physical questions about
the heavenly bodies, despite his intense interest in determining and measuring
their behaviour. 11 The psalmist believes that Jahweh ‘stretched out the earth
above the waters’ (136:6), ‘founded it upon the seas, and established it upon the
floods’ (24:2). Similarly, in the epic of Gilgamesh Marduk builds a raft on the
surface of the original waters, and on it in turn a hut of reeds, which is what the
earth is. Perhaps Thales’ originality consisted only in introducing an opinion
borrowed from sources such as these into Greece, Homer having had the earth