From the Beginning to Plato

THE IONIANS 69
Thus the moon is a compressed (‘felted’) cloud that is on fire. But it ‘does no
work in the boat’, i.e. unlike the sun it does not sustain life. 56 Comets, shooting
stars and meteors are groups or movements of burning clouds. St Elmo’s fire
occurs when cloudlets glimmer owing to a particular sort of movement, and
lightning is very similar. A fragment survives which explains that,
What they call Iris, this too is cloud: purple and red and yellow to behold.
(Scholium bT on the Iliad XI.27: fr. 32 [KRS 178])
Here Xenophanes is undoubtedly attempting to demystify and demythologize the
rainbow. Iris is no goddess, nor is it a ‘marvel to behold’ (thauma idesthai, in
Homeric language), merely a variety of colours ‘to behold’ (idesthai).
The most intriguing of Xenophanes’ astronomical explanations are those he
gives for the stars and the sun. Here the basic identification as burning cloud is
reiterated. But much more detail is given by the doxography. The stars are
quenched each morning but flicker again at night like coals. The sun is generated
anew each day by the collection of widely scattered flaming particles. This
extraordinary idea was probably supported with the claim that the phenomenon
can actually be observed at dawn from the heights of Mount Ida above Homer’s
Troy, when rays originally separate are seen to coalesce into a single ball. 57 It
would seem to follow that the process of coalescence must happen again and
again every day at different longitudes. Xenophanes was not afraid to draw the
logical and undignified conclusion:
Xenophanes says that there are many suns and moons according to
regions, sections and zones of the earth, and that at a particular moment the
disc is banished into some section of the earth not inhabited by us—and so,
tumbling into a hole, as it were, produces the phenomenon of an eclipse.
He also says that the sun goes onward indefinitely, but is thought to move
in a circle because of the distance.
(Aetius II.24.9 [KRS 179])
We have specific reason to think that Xenophanes’ account of the sun occurred
in the same poem as fragment 30: it is quoted by a doxographer who explains that
the vapour from the sea which turns eventually into clouds, showers and winds is
drawn up by the action of the sun (Aetius III.4.4 [DK 21 A 46]).
What epistemological status did Xenophanes accord to these speculations? A
famous and much discussed quatrain gives us his answer, which sounds as
though it might have served as a prologue to one of the physical poems:
No man knows, or ever will know, the clear truth about the gods and about
all the things I speak of. For even if someone happened to say something
exactly so, he himself none the less does not know it, but opinion is what is
the outcome [lit. ‘is constructed’] in all cases.