The Pythagoreans, in applying their theory of numbers to the
geometrical consideration of the five regular bodies, to the musical
intervals of tone which determine a word and form different kinds
of sounds, extended it even to the system of the universe itself;
supposing that the moving, and, as it were, vibrating planets, exciting
sound-waves, must produce a _spheral music_, according to the harmonic
relations of their intervals of space. “This music,” they add, “would
be perceived by the human ear, if it was not rendered insensible by
extreme familiarity, as it is perpetual, and men are accustomed to it
from childhood.”
The Pythagoreans affirm, in order to justify the reality of the
tones produced by the revolution of the spheres, that hearing takes
place only where there is an alternation of sound and silence. The
inaudibility of the spheral music is also accounted for by its
overpowering the senses. Aristotle himself calls the Pythagorean
tone-myth pleasing and ingenious, but untrue.
Plato attempted to illustrate the tones of the universe in an
agreeable picture, by attributing to each of the planetary spheres a
syren, who, supported by the stern daughters of Necessity, the three
Fates, maintain the eternal revolution of the world’s axis. Mention
is constantly made of the harmony of the spheres, though generally
reproachfully, throughout the writings of Christian antiquity and the
Middle Ages, from Basil the Great to Thomas Aquinas and Petrus Alliacus.
At the close of the sixteenth century, Kepler revived these musical
ideas, and sought to trace out the analogies between the relations of
tone and the distances of the planets; and Tycho Brahe was of opinion
that the revolving conical bodies were capable of vibrating the
celestial air (what we now call “resisting medium”) so as to produce
tones. Yet Kepler, although he had talked of Venus and the Earth
sounding sharp in aphelion and flat in perihelion, and the highest tone
of Jupiter and that of Venus coinciding in flat accord, positively
declared there to be “no such things as sounds among the heavenly
bodies, nor is their motion so turbulent as to elicit noise from the
attrition of the celestial air.” (See _Things not generally Known_, p.
44.)
“MORE WORLDS THAN ONE.”
Although this opinion was maintained incidentally by various writers
both on astronomy[16] and natural religion, yet M. Fontenelle was the
first individual who wrote a treatise on the _Plurality of Worlds_,
which appeared in 1685, the year before the publication of Newton’s
_Principia_. Fontenelle’s work consists of five chapters: 1. The earth
is a planet which turns round its axis, and also round the sun. 2. The
moon is a habitable world. 3. Particulars concerning the world in the
moon, and that the other planets are also inhabited. 4. Particulars of
the worlds of Venus, Mercury, Mars, Jupiter, and Saturn. 5. The fixed
stars are as many suns, each of which illuminates a world. In a future
edition, 1719, Fontenelle added, 6. New thoughts which confirm those in
the preceding conversations, and the latest discoveries which have been
made in the heavens. The next work on the subject was the _Theory of
the Universe, or Conjectures concerning the Celestial Bodies and their
Inhabitants_, 1698, by Christian Huygens, the contemporary of Newton.
The doctrine is maintained by almost all the distinguished astronomers
and writers who have flourished since the true figure of the earth was
determined. Giordano Bruna of Nola, Kepler, and Tycho Brahe, believed
in it; and Cardinal Cusa and Bruno, before the discovery of binary
systems among the stars, believed also that the stars were inhabited.
Sir Isaac Newton likewise adopted the belief; and Dr. Bentley, Master
of Trinity College, Cambridge, in his eighth sermon on the Confutation
of Atheism from the origin and frame of the world, has ably maintained
the same doctrine. In our own day we may number among its supporters
the distinguished names of the Marquis de la Place, Sir William and
Sir John Herschel, Dr. Chalmers, Isaac Taylor, and M. Arago. Dr.
Chalmers maintains the doctrine in his _Astronomical Discourses_, which
one Alexander Maxwell (who did not believe in the grand truths of
astronomy) attempted to controvert, in 1820, in a chapter of a volume
entitled _Plurality of Worlds_.
Next appeared _Of a Plurality of Worlds_, attributed to the Rev. Dr.
Whewell, Master of Trinity College, Cambridge; urging the theological
not less than the scientific reasons for believing in the old tradition
of a single world, and maintaining that “the earth is really the
largest planetary body in the solar system,--its domestic hearth,
and the only world in the universe.” “I do not pretend,” says Dr.
Whewell, “to disprove the plurality of worlds; but I ask in vain for
any argument which makes the doctrine probable.” “It is too remote
from knowledge to be either proved or disproved.” Sir David Brewster
has replied to Dr. Whewell’s Essay, in _More Worlds than One, the
Creed of the Philosopher and the Hope of the Christian_, emphatically
maintaining that analogy strongly countenances the idea of all the
solar planets, if not all worlds in the universe, being peopled with
creatures not dissimilar in being and nature to the inhabitants
of the earth. This view is supported in _Scientific Certainties of
Planetary Life_, by T. C. Simon, who well treats one point of the
argument--that mere distance of the planets from the central sun
does not determine the condition as to light and heat, but that the
density of the ethereal medium enters largely into the calculation. Mr.
Simon’s general conclusion is, that “neither on account of deficient
or excessive heat, nor with regard to the density of the materials,
nor with regard to the force of gravity on the surface, is there the
slightest pretext for supposing that all the planets of our system
are not inhabited by intellectual creatures with animal bodies like
ourselves,--moral beings, who know and love their great Maker, and
who wait, like the rest of His creation, upon His providence and upon
His care.” One of the leading points of Dr. Whewell’s Essay is, that
we should not elevate the conjectures of analogy into the rank of
scientific certainties; and that “the force of all the presumptions
drawn from physical reasoning for the opinion of planets and stars
being either inhabited or uninhabited is so small, that the belief of
all thoughtful persons on this subject will be determined by moral,
metaphysical, and theological considerations.”