The fable is a pretty one: but Er the Pamphylian comes back to report no
more than the one thing Man already grasps for a certainty amid his
welter of guesswork about the Universe--that its stability rests on
ordered motion--that the "firmament" stands firm on a balance of active
and tremendous forces somehow harmoniously composed. Theology asks "By
_whom_?": Philosophy inclines rather to guess "_How?_" Natural Science,
allowing that 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 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 at hours which, though mysteriously
appointed, could be accurately predicted; of the moon that she regularly
waxed and waned, drawing the waters of the earth in a flow and ebb, the
gauge of which and the time-table could be advertised beforehand in the
almanack; of the stars, that they swung as by clockwork around the pole.
Says the son of Sirach concerning them--

_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 celestial harmony that men, seeking to account for it
by what was most harmonious in themselves or in their experience,
supposed an actual Music of the Spheres inaudible to mortals; Plato (who
learned of Pythagoras) inventing his Octave of Sirens, spinning in the
whorls of the great planets and intoning as they spin; Chaucer (who
learned of Dante and makes the spheres nine) in his _Parliament of
Foules_ telling, out of Cicero's _Somnium Scipionis_, how the great