The Sleepwalkers (46 page)

When
the
mind
is
split,
departments
of
it
which
should
complete
each
other,
develop
autonomously
by
inbreeding,
as
it
were,
insulated
from
reality.
Such
is
medieval
theology,
cut
off
from
the
balancing
influence
of
the
study
of
nature;
such
is
medieval
cosmology,
cut
off
from
physics;
such
is
medieval
physics,
cut
off
from
mathematics.
The
purpose
of
the
digressions
in
this
chapter,
which
seem
to
have
led
us
so
far
away
from
our
topic,
is
to
show
that
the
cosmology
of
a
given
age
is
not
the
result
of
a
unilinear,
"scientific"
development,
but
rather
the
most
striking,
imaginative
symbol
of
its
mentality
–
the
projection
of
its
conflicts,
prejudices
and
specific
ways
of
double-think
onto
the
graceful
sky.

III THE
UNIVERSE
OF
THE
SCHOOLMEN

I.
The Thaw

I
HAVE
compared
Plato
and
Aristotle
to
twin
stars
which
alternate
in
visibility.
Broadly
speaking,
from
the
fifth
to
the
twelfth
century,
Neoplatonism
in
the
form
in
which
St.
Augustine
and
the
pseudo-Dionysius
had
imported
it
into
Christianity,
held
the
sway.
From
the
twelfth
to
the
sixteenth
century,
it
was
the
turn
of
Aristotle.

Except
for
two
of
his
logical
treatises,
¹
Aristotle's
works
had
been
unknown
before
the
twelfth
century
–
buried
and
forgotten,
together
with
Archimedes,
Euclid,
the
atomists
and
the
rest
of
Greek
science.
What
little
knowledge
survived
had
been
handed
down
in
sketchy,
distorted
versions
by
the
Latin
compilers
and
the
Neoplatonists.
Insofar
as
science
is
concerned,
the
first
six
hundred
years
of
established
Christendom
were
a
glacial
period
with
only
the
pale
moon
of
Neoplatonism
reflected
on
the
icy
steppes.

The
thaw
came
not
by
a
sudden
rise
of
the
sun,
but
by
ways
of
a
devious
Gulf-stream
which
wended
its
way
from
the
Arab
peninsula
through
Mesopotamia,
Egypt
and
Spain:
the
Moslems.
In
the
seventh
and
eighth
centuries,
this
stream
had
picked
up
the
wreckage
of
Greek
science
and
philosophy
in
Asia
Minor
and
in
Alexandria,
and
carried
it
in
a
circumambient
and
haphazard
fashion
into
Europe.
From
the
twelfth
century
onwards,
the
works,
or
fragments
of
works,
of
Archimedes
and
Hero
of
Alexandria,
of
Euclid,
Aristotle,
and
Ptolemy,
came
floating
into
Christendom
like
pieces
of
phosphorescent
flotsam.
How
devious
this
process
of
Europe's
recovery
of
its
own
past
heritage
was,
may
be
gathered
from
the
fact
that
some
of
Aristotle's
scientific
treatises,
including
his
Physics
,
had
been
translated
from
the
original
Greek
into
Syriac,
from
Syriac
into
Arabic,
from
Arabic
into
Hebrew,
and
finally
from
Hebrew
into
medieval
Latin.
Ptolemy's
Almagest
was
known
in
various
Arab
translations
throughout
the
Empire
of
Harun
Al
Rashid,
from
the
Indus
to
the
Ebro,
before
Gerardus
of
Cremona,
in
1175,
retranslated
it
from
the
Arabic
into
Latin.
Euclid's
Elements
were
rediscovered
for
Europe
by
an
English
monk,
Adelard
of
Bath,
who
around
1120,
came
across
an
Arabic
translation
in
Cordova.
With
Euclid,
Aristotle,
Archimedes,
Ptolemy
and
Galen
recovered,
science
could
start
again
where
it
had
left
off
a
millennium
earlier.

But
the
Arabs
had
merely
been
the
go-betweens,
preservers
and
transmitters
of
the
heritage.
They
had
little
scientific
originality
and
creativeness
of
their
own.
During
the
centuries
when
they
were
the
sole
keepers
of
the
treasure,
they
did
little
to
put
it
to
use.
They
improved
on
calendrical
astronomy
and
made
excellent
planetary
tables;
they
elaborated
both
the
Aristotelian
and
the
Ptolemaic
models
of
the
universe;
they
imported
into
Europe
the
Indian
system
of
numerals
based
on
the
symbol
zero,
the
sine
function,
and
the
use
of
algebraic
methods;
but
they
did
not
advance
theoretical
science.
The
majority
of
the
scholars
who
wrote
in
Arabic
were
not
Arabs
but
Persians,
Jews
and
Nestorians;
and
by
the
fifteenth
century,
the
scientific
heritage
of
Islam
had
largely
been
taken
over
by
the
Portuguese
Jews.
But
the
Jews,
too,
were
no
more
than
go-betweens,
a
branch
of
the
devious
Gulf-stream
which
brought
back
to
Europe
its
Greek
and
Alexandrine
heritage,
enriched
by
Indian
and
Persian
additions.