The Sleepwalkers (170 page)

Galileo
remained
in
Padua
for
eighteen
years,
the
most
creative
and
fertile
years
of
his
life.
It
was
here
that
he
laid
the
foundations
of
modern
dynamics,
the
science
concerned
with
moving
bodies.
But
the
results
of
these
researches
he
only
published
towards
the
end
of
his
life.
Up
to
the
age
of
forty-six,
when
the
Messenger
from
the
Stars
was
sent
into
the
world,
Galileo
had
published
no
scientific
work.
⁴
His
growing
reputation
in
this
period,
before
his
discoveries
through
the
telescope,
rested
partly
on
treatises
and
lectures
circulated
in
manuscript,
partly
on
his
mechanical
inventions
(among
them
the
thermoscope,
a
forerunner
of
the
thermometer),
and
the
instruments
which
he
manufactured
in
large
numbers
with
skilled
artisans
in
his
own
workshop.
But
his
truly
great
discoveries
–
such
as
the
laws
of
motion
of
falling
bodies
and
projectiles
–
and
his
ideas
on
cosmology,
he
kept
strictly
for
himself
and
for
his
private
correspondents.
Among
these
was
Johannes
Kepler.

3.
The Church and the Copernican System

The
first
contact
between
the
two
Founding
Fathers
took
place
in
1597.
Kepler
was
then
twenty-six,
a
professor
of
mathematics
in
Gratz;
Galileo
was
thirty-three,
a
professor
of
mathematics
in
Padua.
Kepler
had
just
completed
his
Cosmic
Mystery
and,
profiting
from
a
friend's
journey
to
Italy,
had
sent
copies
of
it,
among
others,
"to
a
mathematician
named
Galileus
Galileus,
as
he
signs
himself".
⁵

Galileo
acknowledged the gift in the following letter:

"Your
book,
my
learned
doctor,
which
you
sent
me
through
Paulus
Amberger,
I
received
not
a
few
days
but
merely
a
few
hours
ago;
since
the
same
Paulus
informed
me
of
his
impending
return
to
Germany,
I
would
be
ungrateful
indeed
not
to
thank
you
at
once:
I
accept
your
book
the
more
gratefully
as
I
regard
it
as
proof
of
having
been
found
worthy
of
your
friendship.
So
far
I
have
only
perused
the
preface
of
your
work,
but
from
this
I
gained
some
notion
of
its
intent,
^*
and
I
indeed
congratulate
myself
on
having
an
associate
in
the
study
of
Truth
who
is
a
friend
of
Truth.
For
it
is
a
misery
that
so
few
exist
who
pursue
the
Truth
and
do
not
pervert
philosophical
reason.
However,
this
is
not
the
place
to
deplore
the
miseries
of
our
century
but
to
congratulate
you
on
the
ingenious
arguments
you
found
in
proof
of
the
Truth.
I
will
only
add
that
I
promise
to
read
your
book
in
tranquility,
certain
to
find
the
most
admirable
things
in
it,
and
this
I
shall
do
the
more
gladly
as
I
adopted
the
teaching
of
Copernicus
many
years
ago,
and
his
point
of
view
enables
me
to
explain
many
phenomena
of
nature
which
certainly
remain
inexplicable
according
to
the
more
current
hypotheses.
I
have
written
[
conscripsi
]
many
arguments
in
support
of
him
and
in
refutation
of
the
opposite
view
–
which,
however,
so
far
I
have
not
dared
to
bring
into
the
public
light,
frightened
by
the
fate
of
Copernicus
himself,
our
teacher,
who,
though
he
acquired
immortal
fame
with
some,
is
yet
to
an
infinite
multitude
of
others
(for
such
is
the
number
of
fools)
an
object
of
ridicule
and
derision.
I
would
certainly
dare
to
publish
my
reflections
at
once
if
more
people
like
you
existed;
as
they
don't,
I
shall
refrain
from
doing
so."

____________________

There
follow
more
polite
affirmations
of
esteem,
the
signature
"Galileus
Galileus",
and
the
date:
4
August,
1597.
⁶

The
letter
is
important
for
several
reasons.
Firstly,
it
provides
conclusive
evidence
that
Galileo
had
become
a
convinced
Copernican
in
his
early
years.
He
was
thirty-three
when
he
wrote
the
letter;
and
the
phrase
"many
years
ago"
indicates
that
his
conversion
took
place
in
his
twenties.
Yet
his
first
explicit
public
pronouncement
in
favour
of
the
Copernican
system
was
only
made
in
1613,
a
full
sixteen
years
after
his
letter
to
Kepler,
when
Galileo
was
forty-nine
years
of
age.
Through
all
these
years
he
not
only
taught,
in
his
lectures,
the
old
astronomy
according
to
Ptolemy,
but
expressly
repudiated
Copernicus.
In
a
treatise
which
he
wrote
for
circulation
among
pupils
and
friends,
of
which
a
manuscript
copy,
dated
1606,
survives,
^6a
he
adduced
all
the
traditional
arguments
against
the
earth's
motion:
that
rotation
would
make
it
disintegrate,
that
clouds
would
be
left
behind,
etc.,
etc.
–
arguments
which,
if
the
letter
is
to
be
believed,
he
himself
had
refuted
many
years
before.