The Sleepwalkers (163 page)

This
kind
of
force,
just
as
the
kind
of
force
which
is
light
...
cannot
be
regarded
as
something
which
expands
into
the
space
between
its
source
and
the
movable
body,
but
as
something
which
the
movable
body
receives
out
of
the
space
which
it
occupies...
^*
It
is
propagated
through
the
universe
...
but
it
is
nowhere
received
except
where
there
is
a
movable
body,
such
as
a
planet.
The
answer
to
this
is:
although
the
moving
force
has
no
substance,
it
is
aimed
at
substance,
i.e.,
at
the
planet-body
to
be
moved...

Who,
I
ask,
will
pretend
that
light
has
substance?
Yet
nevertheless
it
acts
and
is
acted
upon
in
space,
it
is
refracted
and
reflected,
and
it
has
quantity,
so
that
it
may
be
dense
of
sparse,
and
can
be
regarded
as
a
plane
where
it
is
received
by
something
capable
of
being
lit
up.
For,
as
I
said
in
my
Optics
,
the
same
thing
applies
to
light
as
to
our
moving
force:
it
has
no
present
existence
in
the
space
between
the
source
and
the
object
which
it
lights
up,
although
it
has
passed
through
that
space
in
the
past;
it
'is'
not,
it
'was',
so
to
speak."
⁴⁰

____________________

The
contemporary
physicist
grappling
with
the
paradoxa
of
relativity
and
quantum
mechanics
will
find
here
an
echo
of
his
perplexities.
In
the
end,
Kepler
managed
to
get
to
terms
with
his
"moving
force"
by
visualizing
it
as
a
vortex,
"a
raging
current
which
tears
all
the
planets,
and
perhaps
all
the
celestial
ether,
from
West
to
East."
⁴¹
But
he
was
nevertheless
compelled
to
ascribe
to
each
planet
a
kind
of
mind
which
enables
it
to
recognize
its
position
in
space,
and
to
adjust
its
reactions
accordingly.
To
careless
readers
of
the
Astronomia
Nova
this
looked
as
if
the
animal
spirits
had
gained
re-admission
into
the
model
which
he
intended
to
be
a
purely
mechanical
clockwork
–
like
ghosts
who
cannot
resign
themselves
to
their
final
banishment
from
the
world
of
the
living.
But
Kepler's
planetary
minds
bear
in
fact
no
resemblance
to
those
mediaeval
planet-moving
angels
and
spirits.
They
have
no
"souls"
only
"minds";
no
sense
organs,
and
no
will
of
their
own;
they
are
rather
like
the
computing
machines
in
guided
missiles:

"O
Kepler,
does't
thou
wish
then
to
equip
each
planet
with
two
eyes?
Not
at
all.
For
it
is
not
necessary,
either,
to
attribute
them
feet
or
wings
to
enable
them
to
move...
Our
speculations
have
not
yet
exhausted
all
Nature's
treasures,
to
enable
us
to
know,
how
many
senses
exist...

The
subtle
reflections
of
some
people
concerning
the
blessed
angels'
and
spirits'
nature,
motions,
places
and
activities,
do
not
concern
us
here.
We
are
discussing
natural
matters
of
much
lower
rank:
forces
which
do
not
exercise
free
will
when
they
change
their
activities,
intelligences
which
are
by
no
means
separate
from,
but
attached
to,
the
stellar
bodies
to
be
moved,
and
are
one
with
them."
⁴²

Thus
the
function
of
the
planet's
mind
is
confined
to
responding
in
a
lawful,
orderly,
and
therefore
"intelligent"
manner
to
the
various
forces
tugging
at
him.
It
is
really
a
superior
kind
of
electronic
brain
with
an
Aristotelian
bias.
Kepler's
ambiguity
is,
in
the
last
analysis,
merely
a
reflection
of
the
mind-matter
dilemma,
which
becomes
particularly
acute
in
periods
of
transition
–
including
our
own.
As
his
most
outstanding
German
biographer
has
put
it:

"The
physical
expositions
of
Kepler
have
a
special
message
to
those
who
feel
the
need
to
inquire
into
the
first
beginnings
of
the
mechanistic
explanation
of
nature.
He
touches,
indeed,
on
the
profoundest
questions
of
the
philosophy
of
nature
when
he
confronts,
in
his
subtle
manner,
the
concepts
of
mens
and
natura
,
compares
their
pragmatic
values
and
delimits
their
fields
of
application.
Have
we
outgrown
this
antithesis
in
our
day?
Only
those
will
believe
that
who
are
unaware
of
the
metaphysical
nature
of
our
concept
of
physical
force...
At
any
rate,
Kepler's
explanations
may
serve
as
a
stimulus
to
a
wholesome
contemplation
of
the
axioms
and
limits
of
mechanistic
philosophy
in
our
time
of
widespread
and
disastrous
scientific
dogmatism."
⁴³