Carl%20Sagan%20-%20The%20Demon%20Haunted%20World

THE DEMON-HAUNTED WORLD
harmonic equations that describe clockwork really do describe the
motions of astronomical objects throughout the Universe. This is
a profound, not a trivial parallelism.
Of course, there are no gears in the solar system, and the
component parts of the gravitational clockwork do not touch.
Planets generally have more complicated motions than pendulums
and springs. Also, the clockwork model breaks down in certain
circumstances: over very long periods of time, the gravitational
tugs of distant worlds - tugs that might seem wholly insignificant
over a few orbits - can build up, and some little world can go
unexpectedly careening out of its accustomed course. However,
something like chaotic motion is also known in pendulum clocks;
if we displace the bob too far from the perpendicular, a wild and
ugly motion ensues. But the solar system keeps better time than
any mechanical clock, and the whole idea of keeping time comes
from the observed motion of the Sun and stars.
The astonishing fact is that similar mathematics applies so well
to planets and to clocks. It needn't have been this way. We didn't
impose it on the Universe. That's the way the Universe is. If this is
reductionism, so be it.
Until the middle twentieth century, there had been a strong
belief - among theologians, philosophers and many biologists -
that life was not 'reducible' to the laws of physics and chemistry,
that there was a 'vital force', an 'entelechy', a tao, a mana that
made living things go. It 'animated' life. It was impossible to see
how mere atoms and molecules could account for the intricacy and
elegance, the fitting of form to function, of a living thing. The
world's religions were invoked: God or the gods breathed life,
soul-stuff, into inanimate matter. The eighteenth-century chemist
Joseph Priestley tried to find the 'vital force'. He weighed a mouse
just before and just after it died. It weighed the same. All such
attempts have failed. If there is soul-stuff, evidently it weighs
nothing, that is, it is not made of matter.
Nevertheless, even biological materialists entertained reservations;
perhaps, if not plant, animal, fungal and microbial souls,
some still undiscovered principle of science was needed to understand
life. For example, the British physiologist J.S. Haldane
(father of J.B.S. Haldane) asked in 1932:
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