Parmenides maintains that there are small coronets alternately twisted
one within another, some made up of a thin, others of a condensed,
matter; and there are others between mixed mutually together of light
and of darkness, and around them all there is a solid substance, which
like a firm wall surrounds these coronets. Leucippus and Democritus
cover the world round about, as with a garment and membrane. Epicurus
says that that which abounds some worlds is thin, and that which limits
others is gross and condensed; and of these spheres some are in motion,
others are fixed. Plato, that fire takes the first place in the world,
the second the aether, after that the air, under that the water; the
last place the earth possesseth: sometimes he puts the aether and the
fire in the same place. Aristotle gives the first place to the aether,
as that which is impassible, it being a kind of a fifth body after which
he placeth those that are passible, fire, air, and water, and last of
all the earth. To those bodies that are accounted celestial he assigns
a motion that is circular, but to those that are seated under them,
if they be light bodies, an ascending, if heavy, a descending motion.
Empedocles, that the places of the elements are not always fixed
and determined, but they all succeed one another in their respective
stations.