The Sleepwalkers (195 page)

It
is
the
same
dichotomy
which
we
observed
in
all
his
activities
and
attitudes.
In
his
quarrels
with
Tycho
and
constant
naggings
at
him,
he
displayed
embarrassing
pettiness.
Yet
he
was
curiously
devoid
of
jealousy
or
lasting
resentment.
He
was
proud
of
his
discoveries
and
often
boasted
of
them
(particularly
of
those
which
turned
out
to
be
worthless),
but
he
had
no
proprietary
feeling
about
them;
he
was
quite
prepared
to
share
the
copyright
of
the
three
Laws
with
the
Junker
Tengnagel
and,
contrary
to
the
habits
of
the
time,
gave
in
all
his
books
most
generous
credit
to
others
–
to
Maestlin,
Brahe,
Gilbert
and
Galileo.
He
even
gave
credit
where
none
was
due,
for
instance
to
Fabricius,
whom
he
nearly
saddled
with
the
honour
of
having
discovered
the
elliptic
orbits.
He
freely
informed
his
correspondents
of
his
latest
researches
and
naïvely
expected
other
astronomers
to
part
with
their
jealously
guarded
observations;
when
they
refused,
as
Tycho
and
his
heirs
did,
he
simply
pinched
the
material
without
a
qualm
of
conscience.
He
had,
in
fact,
no
sense
of
private
property
concerning
scientific
research.
Such
an
attitude
is
most
unusual
among
scholars
in
our
day;
in
Kepler's
day
it
seemed
quite
insane.
But
it
was
the
most
endearing
lunacy
in
his
discordant,
fantastic
self.

XI THE
LAST
YEARS

1.
Tabulae Rudolphinae

ARMONICE
MUNDI
was
completed
in
1618
and
published
the
next
year,
when
Kepler
was
forty-eight.
His
pioneering
work
was
done;
but
in
the
remaining
eleven
years
of
his
life
he
continued
to
pour
out
books
and
pamphlets
–
annual
calendars
and
ephemerides,
a
book
on
comets,
another
on
the
new
invention
of
logarithms,
and
two
more
major
works:
the
Epitome
Astronomiae
Copernicanae
and
the
Rudolphine
Tables
.

The
title
of
the
former
is
misleading.
The
Epitome
is
not
an
abstract
of
the
Copernican
system,
but
a
textbook
of
the
Keplerian
system.
The
laws
which
originally
referred
to
Mars
only,
are
here
extended
to
all
planets,
including
the
moon
and
the
satellites
of
Jupiter.
The
epicycles
are
all
gone,
and
the
solar
system
emerges
in
essentially
the
same
shape
in
which
it
appears
in
modern
school-books.
It
was
Kepler's
most
voluminous
work
and
the
most
important
systematic
exposition
of
astronomy
since
Ptolemy's
Almagest
.
The
fact
that
his
discoveries
are
found
in
it
once
more
side
by
side
with
his
fantasies,
does
not
detract
from
its
value.
It
is
precisely
this
overlapping
of
two
universes
of
thought,
which
gives
the
Epitome
,
as
it
does
to
the
whole
of
Kepler's
life
and
work,
its
unique
value
to
the
history
of
ideas.

To
realize
how
far
ahead
of
his
colleagues
Kepler
was,
in
spite
of
the
residue
of
medievalism
in
his
veins,
one
must
compare
the
Epitome
with
other
contemporary
textbooks.
None
of
them
had
adopted
the
heliocentric
idea,
or
was
to
do
so
for
a
generation
to
come.
Maestlin
published
a
reprint
of
his
textbook
based
on
Ptolemy
in
1624,
three
years
after
the
Epitome
;
and
Galileo
famous
Dialogue
on
the
Great
Systems
of
the
World
,
published
another
eight
years
later,
still
holds
fast
to
cycles
and
epicycles
as
the
only
conceivable
form
of
heavenly
motion.

The
second
major
work
of
Kepler's
late
years
was
his
crowning
achievement
in
practical
astronomy:
the
long-awaited
Rudolphine
Tables,
based
on
Tycho's
lifelong
labours.
Their
completion
had
been
delayed
for
nearly
thirty
years
by
Tycho's
death,
the
quarrel
with
the
heirs,
and
the
chaotic
conditions
created
by
the
war
–
but
basically
by
Kepler's
reluctance
against
what
one
might
call
a
Herculean
donkey-work.
Astronomers
and
navigators,
calendar-makers
and
horoscope-casters
were
impatiently
waiting
for
the
promised
Tables,
and
angry
complaints
about
the
delay
came
from
as
far
as
India
and
the
Jesuit
missionaries
in
China.
When
a
Venetian
correspondent
joined
in
the
chorus,
Kepler
answered
with
a
cri
de
cœur
:

"One
cannot
do
everything,
as
the
saying
goes.
I
am
unable
to
work
in
an
orderly
manner,
to
stick
to
a
time
schedule
and
to
rules.
If
I
put
out
something
that
looks
tidy,
it
has
been
worked
over
ten
times.
Often
I
am
held
up
for
a
long
time
by
a
computing
error
committed
in
haste.
But
I
could
pour
out
an
infinity
of
ideas...
I
beseech
thee,
my
friends,
do
not
sentence
me
entirely
to
the
treadmill
of
mathematical
computations,
and
leave
me
time
for
philosophical
speculations
which
are
my
only
delight."
¹