and
an orrery, and therefore is necessarily inconsistent with itself. The
column of light is not the Milky Way--which is neither straight, nor
like a rainbow--but the imaginary axis of the earth. This is compared
to the rainbow in respect not of form but of colour, and not to the
undergirders of a trireme, but to the straight rope running from prow to
stern in which the undergirders meet.

The orrery or picture of the heavens given in the Republic differs in
its mode of representation from the circles of the same and of the
other in the Timaeus. In both the fixed stars are distinguished from the
planets, and they move in orbits without them, although in an opposite
direction: in the Republic as in the Timaeus they are all moving round
the axis of the world. But we are not certain that in the former they
are moving round the earth. No distinct mention is made in the Republic
of the circles of the same and other; although both in the Timaeus and
in the Republic the motion of the fixed stars is supposed to coincide
with the motion of the whole. The relative thickness of the rims is
perhaps designed to express the relative distances of the planets.
Plato probably intended to represent the earth, from which Er and his
companions are viewing the heavens, as stationary in place; but whether
or not herself revolving, unless this is implied in the revolution of
the axis, is uncertain (Timaeus). The spectator may be supposed to look
at the heavenly bodies, either from above or below. The earth is a sort
of earth and heaven in one, like the heaven of the Phaedrus, on the back
of which the spectator goes out to take a peep at the stars and is borne
round in the revolution. There is no distinction between the equator and
the ecliptic. But Plato is no doubt led to imagine that the planets have
an opposite motion to that of the fixed stars, in order to account for
their appearances in the heavens. In the description of the meadow, and
the retribution of the good and evil after death, there are traces of
Homer.

The description of the axis as a spindle, and of the heavenly bodies as
forming a whole, partly arises out of the attempt to connect the motions
of the heavenly bodies with the mythological image of the web, or
weaving of the Fates. The giving of the lots, the weaving of them,
and the making of them irreversible, which are ascribed to the three
Fates--Lachesis, Clotho, Atropos, are obviously derived from their
names. The ele