evolving around it in graduated whorls of width and
spread: yet all concentric and so timed that all complete the
full circle punctually together--'The Spindle turns on the knees
of Necessity; and on the rim of each whorl sits perched a Siren
who goes round with it, hymning a single note; the eight notes
together forming one harmony.'

Now as--we have the divine word for it--upon two great
commandments hang all the law and the prophets, so all
religions, all philosophies, hang upon two steadfast and
faithful beliefs; the first of which Plato would show by the
above parable.

It is, of course, that the stability of the Universe rests upon
ordered motion--that the 'firmament' above, around, beneath,
stands firm, continues firm, on a balance of active and
tremendous forces somehow harmoniously composed. Theology asks
'by What?' or 'by Whom?' Philosophy inclines rather to ask 'How?'
Natural Science, allowing that for the present these questions
are probably unanswerable, contents itself with mapping and
measuring what it can of the various forces. But all agree about
the harmony; and when a Galileo or a Newton discovers a single
rule of it for us, he but makes our assurance surer. For
uncounted centuries before ever hearing of Gravitation men knew
of the sun that he rose and set, of the moon that she waxed and
waned, of the tides that they flowed and ebbed, all regularly, at
times to be predicted; of the stars that they swung as by
clockwork around the pole. Says the son of Sirach:

At the word of the Holy One they will stand in due order,
And they will not faint in their watches.

So evident is this calculated harmony that men, seeking to
interpret it by what was most harmonious in themselves or in
their human experience, supposed an actual Music of the Spheres
inaudible to mortals: Plato as we see (who learned of Pythagoras)
inventing his Octave of Sirens, perched on the whorls of the
great spindle and intoning as they spin.

Dante (Chaucer copying him in "The Parlement of Fowls") makes the
spheres nine: and so does Milton:

then listen I
To the celestial _Sirens_ harmony,
That sit upon the nine infolded Sphears,
And sing to those that hold the vital shears,
And turn the Adamantine spindle round
On which the fate of gods and men is wound.
Such sweet compulsion doth in musick lie
To lull the daughters of _Necessity_,
And keep unsteady Nature to her law,
And the low world in me