1.
We shall consider astronomy at the time when
it began to stir, that
is, when the sky was discovered
to be observable, when the personality of
astronomers
and their relations to their cultural environment be-
came more accessible to investigation. And we
shall
follow this intellectual adventure only until the first
third of
the twentieth century when the Einsteinian
theory of relativity gradually
brought to the uninitiated
an unimaginable world. Individual psychology
will be
only a secondary consideration. (Kepler's psychology,
for
example, has been admirably studied by Nicolson
and Koestler.) It is rather
the turn of imagination
characterizing a whole era which will be
discussed
here.
We start with the Ptolemaic cosmos, an improve-
ment on Aristotle, whose reign, established in the
thirteenth
century, was soon to crumble. Ptolemaic
astronomy provided a home for the
Parmenidean imagi-
nation and satisfied both
of its intellectual and aes-
thetic demands: a
refuge secured by the closed-in
cavernous Cosmos in which the stars,
solidly attached
to their spherical vaults of rigid ether, followed
these
spheres in their eternal rounds. It provided, with a
sense of
security, the intellectual satisfaction of simple
mathematical relations
and the aesthetic delight of a
perfect harmony: circles and spheres,
inserted within
a single finite Sphere outside of which nothing
existed
except the world of pure minds.
It is true that this perfect image was merely a
simplification, for the
uninitiated, of a more hetero-
geneous and
complicated view. There was the duality,
unacceptable to a rigorous mind,
of the incorruptible
superlunar spheres and of the impure sublunar
sphere
of the Earth subject to change, this very Earth which
paradoxically formed the center of the whole system,
i.e., usurped what
was, for the spontaneous imagina-
tion, the
place of honor. Only astrological influences
wove a network from one world
to the other without
succeeding in unifying them. There was also the in-
creasing complexity of celestial mechanics
accom-
panying progress in the
observation of celestial move-
ments, which
required the refinement of Ptolemy's
system; efforts made to
“save the appearances” and
to preserve the dogma of
the Circle greatly compro-
mised the simple
harmony of the Great Dance. The
aim of Copernicus' De
revolutionibus (1543) was pre-
cisely to restore that simplicity, and to do it by return-
ing to the heliocentric view of Pythagoreans like
Heraclides of Pontus. Copernicus, as Koestler has
shown, was Parmenidean: to solve the mathematical
problem of
the world, Copernicus sought a more ele-
gant
solution than Ptolemy's and wished to repair the
old clock by changing the
arrangement of its wheels.
However, around Copernicus an intellectual ferment
was taking place in which
he did not seem to partici-
pate; and, as in
times of crises, the two families of
minds became self-conscious and
opposed each other.
The return to favor of Neo-Platonism at the end of
the fifteenth century
contributed to the unification of
the world. Marsilio Ficino explained
astrological influ-
ences by the Spirit of
the World (Spiritus mundi), a
kind of vital
fluid which came from the stars and
planets to impregnate our earthly abode
(De vita libri
tres, 1489). Thinkers were
thus prepared to accept the
unity of substance between our Earth and the
other
heavenly bodies. Moreover, the Platonic cult of the
divine Light
and of the Sun as the image of the Idea
of the Good, encouraged these
thinkers to accept the
central place which Copernicus was to assign to
this
orb, and he did so with visible satisfaction. In addition,
they
were prepared to accept the role of the Sun as
the mover of the planets, a
role which Kepler was later
to attribute to it (Astronomia nova, 1609).
Moreover, a new state of mind was created: man
took confidence in his powers
to explore the world and
to make use of it, affirming an idea that the
world was
put at his disposal by God. The outstanding work in
which
this assurance was expressed is the Oration on
the
Dignity of Man (1436) by Pico della Mirandola.
For the first time
Prometheus had a clear conscience.
A new boldness inspired him: he no
longer needed the
safeguard of a protective shell; the rigid casement
of
the celestial spheres seemed like a prison to him, as
did the
infallible doctrine of Aristotle. A curiosity that
was both more exact and
more extended encouraged
voyages of exploration, and in turn was developed
by
them. This curiosity extended to the celestial domain,
where it was
believed there was nothing more to dis-
cover.
Finally, a fresh love of life led to the joyous
acceptance of everything
life brought with it: genera-
tion
and decay. Alchemy contributed to this appraisal
of
the vital cycle that was thought to be realized in
the alchemist's oven
(athanor); and the incorruptible
nature of the
starry world lost its prestige. This cult
of life and this explorer's sort
of boldness found perfect
expression in Galileo (Dialogue
on the Two Main Sys-
tems of the World,
1632). In this work he proclaimed
the superiority of the living over the
static:
As for me, I hold the Earth as noble and admirable because
of the
numerous and varied alterations, mutations, and
generative changes that
take place in it.
And with regard to Aristotle's authority:
Only the blind need a guide, but anyone with two eyes
in his head and
with a mind should use them to guide
himself.
However, this turn of mind had asserted itself much
earlier. Thanks to it
certain events in the sky—the
outburst of new stars (the Novae of 1572 and 1604)
and the passing of comets,
introducing change in the
immutable superlunar heaven—created a
sensation and
excited discussions. Concerning the Copernican clock-
work, the followers of Heraclitus would
maintain above
all that the “Sphere of the Fixed
Stars” had become
useless because it no longer moved; it could
dissolve
and open out on the Infinite. It was thus that, before
the
crucial astronomical discoveries were made, G.
Bruno (in his Dialogues, 1584) was able to put forth
through the
power of his imagination a typical
Heraclitean cosmos: an infinite space,
infinitely full,
an inexhaustible, creative gushing of energy, an un-
limited number of suns as centers of as many
infinitely
varied planetary systems, endless degrees of Perfection,
an
equilibrium in motion, a network of transformations
and of perpetually new
forms—all of it alive and giving
birth to life. No hesitancy in
Bruno; he trampled with
the rapturous fury of an iconoclast over the ruins
of
the old cosmos, and the impulse of liberation and
departure on his
part was unattended by any appre-
hensiveness or by any looking back. From Bruno came
the avid concern
for the infinite which we find in
British thought of the seventeenth
century; following
Bruno also, intoxication with life and variety was
henceforth linked to the theme of the “Plurality of
Worlds,” a theme which would still be alive in the
work of
Camille Flammarion and in novels of the
twentieth century.