The Sleepwalkers (95 page)

Thus
Copernicus'
first
impulse
to
reform
the
Ptolemaic
system
originated
in
his
urge
to
remove
a
minor
blemish
from
it,
a
feature
which
did
not
strictly
conform
to
conservative
Aristotelian
principles.
He
was
led
to
reversing
the
Ptolemaic
system
by
his
desire
to
preserve
it
–
like
the
maniac
who,
pained
by
a
mole
on
his
beloved's
cheek,
cut
off
her
head
to
restore
her
to
perfection.
Yet
it
happened
not
for
the
first
time
in
history
that
a
puritan
reformer
started
by
attacking
a
minor
imperfection,
and
ended
by
realizing
that
it
was
a
symptom
of
a
deeprooted
and
irremediable
disease.
Ptolemy's
equants
were
nothing
to
get
excited
about,
but
they
were
symptomatic
of
the
jarring
artificiality
of
the
system.

Once
he
had
started
to
take
the
Ptolemaic
clockwork
to
pieces,
he
was
on
the
lookout
for
some
useful
hint
how
to
rearrange
the
wheels
in
a
different
order.
He
did
not
have
to
look
for
long:

"I
therefore
went
to
the
trouble
of
reading
anew
the
books
of
all
philosophers
on
which
I
could
lay
hands,
to
find
out
whether
someone
did
not
hold
the
opinion
that
there
existed
other
motions
of
the
heavenly
bodies
than
assumed
by
those
who
taught
the
mathematical
sciences
in
the
schools.
And
thus
I
found
first
in
Cicero
that
Hiketas
had
held
the
belief
that
the
earth
moves.
Afterwards
I
found
in
Plutarch
^*
that
others
have
also
held
this
opinion.
I
shall
put
down
his
own
words
so
that
everybody
can
read
them:

'But
others
hold
that
the
earth
moves;
thus
Philolaus
the
Pythagorean
held
that
it
revolves
round
the
Fire
in
an
oblique
circle
like
the
sun
and
moon.
Herakleides
of
Pontus
and
Ekphantus
the
Pythagorean
also
suppose
the
earth
to
move,
though
not
in
a
progressive
motion,
but
after
the
manner
of
a
wheel,
turning
upon
an
axle
about
its
own
centre
from
west
to
east.'

And
so,
taking
occasion
from
this,
I
too
began
to
think
about
the
mobility
of
the
earth.
And
although
it
seemed
an
absurd
opinion,
yet,
because
I
knew
that
others
before
me
had
been
granted
the
liberty
of
supposing
whatever
orbits
they
chose
in
order
to
demonstrate
the
phenomena
of
the
stars,
I
considered
that
I
too
might
well
be
allowed
to
try
whether
sounder
demonstrations
of
the
revolutions
of
the
heavenly
orbs,
might
be
discovered
by
supposing
some
motion
of
the
earth."
²⁵

____________________

There
are
further
references
²⁶
to
"the
Pythagoreans
Herakleides
and
Ekphantus",
and
to
"Hiketas
of
Syracuse,
who
let
the
earth
rotate
in
the
centre
of
the
world".
Then,
in
Book
I,
chapter
10,
called
About
the
order
of
the
heavenly
orbits
,
Copernicus
gives
us
his
own
version
of
the
Genesis
of
his
system:

"Therefore
it
seemed
to
me
that
it
would
be
wrong
to
ignore
certain
facts
well-known
to
Martianus
Capella,
who
wrote
an
encyclopaedia,
and
of
some
other
Latins.
He
believed
that
Venus
and
Mercury
do
not
go
round
the
earth
like
other
planets,
but
turn
round
the
sun
as
their
centre
and
therefore
cannot
go
farther
away
from
the
sun
than
the
sizes
of
their
orbits
permit.
What
else
does
this
mean
but
that
the
sun
is
the
centre
of
their
orbits
and
that
they
turn
round
him?
Thus
the
sphere
of
Mercury
would
be
enveloped
by
that
of
Venus
which
is
twice
as
large
and
would
find
sufficient
space
inside
it.
If
we
seize
the
opportunity
to
refer
Saturn,
Jupiter
and
Mars
to
the
same
centre
[i.e.
the
sun]
...
then
their
motions
will
fall
into
a
regular
and
explainable
order...
And
as
now
all
of
them
are
arranged
round
the
same
centre,
so
it
becomes
necessary
that
the
space
which
is
left
between
the
convex
surface
of
the
sphere
of
Venus
and
the
concave
sphere
of
Mars
should
be
filled
in
by
the
earth
and
the
moon
which
accompanies
it
and
by
all
the
matter
to
be
found
in
the
sublunary
sphere...
Therefore
we
do
not
hesitate
to
state
that
moon
and
earth
describe
annually
a
circular
orbit
placed
between
the
outer
and
the
inner
planets
round
the
sun,
which
rests
immobile
in
the
centre
of
the
world;
and
that
everything
which
appears
as
a
motion
of
the
sun
is
in
truth
a
motion
of
the
earth."