Hellenistic Philosophy Introductory

The Extant Letters 27
around which the rest rotates is stationary, as some people say, but also
because there is a circular rotation of air around it which prevents them
from wandering around, as the other heavenly bodies do; or also because
they do not have any appropriate fuel in adjacent regions, while there is
[a supply of fuel] in the area where they are observed. And this [phenome-
non] could also be produced in several other ways, provided one can
reason out what is consistent with the appearances.
The wandering of some of the heavenly bodies, if they really do happen
to have this kind of movement, 113. and the regular motion of others
could be a result of them starting out with circular movement and [then]
having been forced in such a way that some of them move in the same
uniform rotation while others move with a rotation which at the same
time has certain irregularities; and it could also be that, according to the
regions over which they move, in one place there are uniform regions
of air which push them on continuously in the same direction and which
burn uniformly, while elsewhere there are irregular [regions of air] of
such a nature that the observed differences are produced. But to supply
one cause for these facts, when the phenomena suggest that there are
several different explanations, is the lunatic and inappropriate behaviour
of those who are obsessed with a pointless [brand of] astronomy and of
certain [others] who supply vain explanations, since they do not in any
way liberate the divine nature from burdensome service. 114. That some
heavenly bodies are observed being left behind by others occurs because
although they move around in the same orbit they do so more slowly;
and because they also move in the opposite direction being drawn back-
wards by the same rotation; and also because some rotate through a larger
area and some through a smaller, though they turn with the same rotation.
But to pronounce unqualifiedly on these matters is appropriate to those
who wish [only] to make a display of wonders for the masses.
So-called falling stars could be produced in part by their own friction,
and also because they fall wherever there is a massive outburst of wind,
just as we said [occurred] in the case of lightning flashes; 115. also by a
collection of atoms capable of producing fire, when similar material
[congregates] to produce this result and also a motion where the surge
produced by the original collection occurs; and also because wind is
concentrated in certain dense and misty places and this ignites as a result
of its confinement, then breaks through the surrounding environment
and is borne to the place to which the movement makes its surge; and
there are other non-mythical ways in which this phenomenon could
be produced.
The predictive weather signs which occur in certain animals occur by
a coincidental conjunction of events; for the animals do not bring any