656
DOC.
627
SEPTEMBER
1918
been
a
downright
malicious critic.
This,
at
least, is
the
view of
many
of
my
colleagues
in
the
field.
Vox populi,
vox
dei.
The
majority is
always right!
I
abandon
the
statement
that mathematics
belongs
within
logic.[3]
I
myself
do
not
understand
how
I
could
have written
that. What
I actually meant, I cannot
say,
I
appear
not to have
kept any proofs
of this
paper.
Presumably I
only
wanted
to
emphasize
the
contrast to
empiricism.
However,
I
cannot
set
the
statement
that
the
external world
is
real
=
cock-
a-doodle-doo. If this statement makes
no sense (as you say),
then the
antithesis:
the external
world
is
unreal,
a
chimera,
also makes
no sense.
I
do think,
though,
that this
statement
is
understood
by anyone
who
says:
“The devil does not
exist,
the
devil
is
a
chimera.” The content of such
statements cannot be
explained,
but
at most
clarified (with
familiar
examples).
You
use
such
an
explanation
nonetheless in
that
you,
as a
pragmatist
in
the
style
of Poincaré
(forgive
me,
but
no one can
avoid
the
isms!),
set out
from
the
correct
comment
that
more can
be
done
with the
“real”
than with the
“unreal,”
and
then
want to
apply
it
to
the
definition
for
the
real. At
least,
that
is
how
I
understand
you.
But then
you
have
the
biological advantage
as a
criterion for
truth
or as a
basis for
proof,
and
with
it
the
entire
litany
of
pragmatism.
What
you
call “offshoots”
become,
in
my view,
the
correctly
drawn
consequences
of
your premise;
I do not believe
that
this
premise
can
be
admitted
and
the
consequences rejected.
And
now
I’ll turn
the
tables.
I
did
grin,
as a
matter of
fact,
when
I
read at
the
top
of
your page
7
“that orbits
of themselves do not
exist."[4]
What
does “exist”
mean?
Oh,
it’s
senseless! Likewise
p.
42,
when
you speak
of “absolute
physical
reality.”
I allow
you this,
but
you
should
not allow
yourself
this! Otherwise
I’ll
come
and
say
cock-a-doodle-doo!
I
do not
understand what
you
have
against
my concept
of
natural
geometry
and
some
other
things
as
well. I
shall
save
up your
letter, of
course,
and when
I
come
to
Berlin
sometime,
I’ll
bring
it
along.
Corresponding
about
such
a
thing,
which
after
all
is not
urgent,
I
would
perceive
as an
abuse of
your
kindness.
I
would
prefer
to
chat
with
you
now
about
your
book.
Our
difference of
opinion,
which
is
indeed
not
great,
can
be
illustrated
com-
pletely
with the
statement
on p.
7
already
commented
on
above. I
find
that
the
thesis of
the
theory
of
relativity is
(1)
somewhat
carelessly
written,
(2)
dogmati-
cally, (3)
unclearly.
1)
All
physical
relations
that
we
know
of
are
relative.
Having
made
this
completely
clear and
having
said
what
significance
such
a
statement has
is
your
great
discovery.
But then
you
assert
something
more:
that
an
absolute
place
in
space,
in which
the
physical
laws
(known
to
us)
do not
cease
to
hold,
also “does
not
exist.” As
long
as
radioactive bodies
were
not
found, anyone
who would have