The Sleepwalkers (20 page)

It
all
looks
beautifully
obvious
–
in
the
rear
mirror.
But
there
are
situations
where
it
needs
great
imaginative
power,
combined
with
disrespect
for
the
traditional
currents
of
thought,
to
discover
the
obvious.
The
scant
information
we
have
about
the
personality
of
Herakleides
shows
that
he
had
both:
originality,
and
contempt
for
academic
tradition.
He
was
nicknamed
by
his
acquaintances
the
paradoxolog
–
a
maker
of
paradoxes;
Cicero
relates
that
he
was
fond
of
telling
"puerile
fables"
and
"marvellous
stories";
and
Proclus
tells
us
that
he
had
the
audacity
to
contradict
Plato,
who
taught
the
immobility
of
the
earth.
⁸

The
idea
that
the
two
lower
planets
–
and
only
these
two
–
were
satellites
of
the
sun,
while
the
sun
itself
and
the
remaining
planets
still
revolved
round
the
earth,
became
later
known
by
the
misnomer
"Egyptian
System"
and
gained
great
popularity
(
Fig.
B
,
p.
46).
It
was
evidently
a
half-way
house
between
the
geocentric
(earth-centred)
and
heliocentric
(sun-centred)
conceptions
of
the
universe.
We
do
not
know
whether
Herakleides
stopped
there,
or
whether
he
took
the
further
step
of
letting
the
three
outer
planets
also
go
around
the
sun,
and
the
sun,
with
all
his
five
satellites,
go
round
the
earth
(
Fig.
C
,
p.
46).
It
would
have
been
a
logical
step,
and
some
modern
scholars
believe
that
Herakleides
did
reach
this
three-quarter-way
house
⁹
.
Some
even
believe
that
he
also
took
the
ultimate
step
of
making
all
the
planets,
including
the
earth,
revolve
around
the
sun.

But
whether
he
went
the
whole
way
to
the
modern
conception
of
the
solar
system
or
not,
is
merely
a
matter
of
historic
curiosity,
for
his
successor,
Aristarchus,
certainly
did.

3.
The Greek Copernicus

Aristarchus,
last
of
the
line
of
the
Pythagorean
astronomers,
came,
like
the
Master,
from
Samos;
and
he
is
supposed
to
have
been
born,
symbolically,
in
the
same
year,
310
B.C.,
in
which
Herakleides
died.
^*
Only
one
short
treatise
of
his
survives:
On
the
Sizes
and
Distances
of
the
Sun
and
Moon
.
It
shows
that
he
had
the
basic
gifts
required
of
a
modern
scientist:
originality
of
thought
and
meticulousness
in
observation.
The
elegant
method
he
designed
for
calculating
the
distance
of
the
sun
was
followed
by
astronomers
throughout
the
Middle
Ages;
if
his
actual
figures
were
wrong,
it
was
due
to
the
fact
that
he
was
born
two
thousand
years
before
the
telescope.
But
though
an
equal
distance
separated
him
from
the
invention
of
the
pendulum
clock,
he
improved
the
estimates
of
the
length
of
the
solar
year
by
adding
1/1623
to
the
previous
estimate
of
365
1/4
days.

____________________

The
treatise
in
which
Aristarchus
proclaimed
that
the
sun,
not
the
earth,
was
the
centre
of
our
world
around
which
all
planets
revolve
–
this
crowning
achievement
of
Pythagorean
cosmology,
which
Copernicus
was
to
rediscover
seventeen
centuries
later
–
is
lost.
But
fortunately,
we
have
the
testimony
of
no
smaller
authorities
than
Archimedes
and
Plutarch,
among
others;
and
the
fact
that
Aristarchus
taught
the
heliocentric
system
is
unanimously
accepted
by
the
ancient
sources
and
modern
scholars.

Archimedes,
the
greatest
mathematician,
physicist
and
inventor
of
antiquity,
was
a
younger
contemporary
of
Aristarchus.
One
of
his
most
curious
works
is
a
little
treatise
called
The
Sand
Reckoner
,
dedicated
to
King
Gelon
of
Syracuse.
It
contains
the
crucial
phrase:
"For
he
(
Aristarchus
of
Samos)
supposed
that
the
fixed
stars
and
the
sun
are
immovable,
but
that
the
earth
is
carried
round
the
sun
in
a
circle..."
¹⁰

Plutarch's
reference
to
Aristarchus
is
equally
important.
In
his
treatise
On
the
Face
in
the
Moon
Disc,
one
of
the
characters
refers
to
Aristarchus
of
Samos
who
thought
"that
the
heaven
is
at
rest,
but
that
the
earth
revolves
in
an
oblique
orbit,
while
it
also
rotates
about
its
own
axis."
¹¹