394
DOC.
395
OCTOBER
1917
what
we
know
for
certain,
but rather with
isolating
out
of
the
given
worldview
a
specific
quality
that
seems
to
me
the
genuinely
real basis of
it,
whereas
the
rest
are
auxiliary
constructions and fictions. Mach and
Avenarius have also
posed
this
problem,
of
course,
but
they
arrived
at
different
results.[7]
On
this
basis
I
assume
furthermore,
on
the
one
hand,
that
our
human
con-
sciousness
must
be
regarded
as
the
thing-in-itself [Ding
an sich],
as
the
basically
real for
the
cerebrum,
so
that
we
know
exactly
the
reality
underlying
this
one
physical object and,
on
the other
hand,
that other
physical
objects
are
based
on
something
more or
less
analogous
to
our
consciousness:
resembling
it to
the
ex-
tent
that other
living
bodies with
our
brain share
general physical
characteristics,
and
differing
from
it
to
the
extent
that
they differ.
In this
way
I
believe
a
meta-
physics
is
possible
which,
although
not
provable,
is nevertheless admissible in
principle,
since
it
construes
the unknown
by analogy
with the
really
known.
The
idea of
constructing metaphysics
on
an
empirical
basis
in this
way,
in that what
really
underlies
things
is
conceived
as
analogous
to
our
psyche,
seems
to
me
to
be Leibniz’s
great
philosophical
achievement.
My metaphysics
differs from
that
of Leibniz in
that
for him
the
entire soul
(with
the
passage
of time
as
content) is
regarded
as a
monad;
for
me, however,
it
is
the
state,
and
I
therefore
imagine
the
monads unknown to
us as
analogous
not to
the
soul
but
to
the
state
of
conscious-
ness.
In
any event,
it
seems
to
me
the
only metaphysics possibly
admissible would
be
one
that
builds
upon
the
foundation
of
the
only reality
of
consciousness
truly
known to
us.
Perhaps
no
metaphysical approach
will
appeal
to
you;
nevertheless,
I
invite
you
to consider
whether
the
above chains
of
reasoning
are
not legitimate
nonetheless.
As
far
as
your
other
remarks
on
my philosophy
are
concerned,
I unfortunately
found
that
you
did
not
understand
me
correctly.
This
was
troublesome
to
me
for various
reasons
and muted
my delight
in
your
letter.
I
was
sorry,
first
and
foremost,
that
I
was
not
understood
properly
by
you
in
particular,
since
then
only
bleaker
prospects
must
await
me
for
comprehension by
the
public
at
large;
for if
you
do not
immediately
understand the
matter
completely,
it
is
very
much to be
feared
that
most
persons
will
not be
capable
of
doing
so
at all.
In
these
points
I
do still
hope, though,
to
be able to convince
you
that
you
had
not
grasped
the
matter
clearly enough
and that
this
is
the
reason
for
your
subsequent
comments.
I naturally
assume
that
you
will
not take
offense
at
my
frank
rebuttal.
To start
with, you
write
that
the
more
intently
one
concentrates
on
pin-
pointing
the instantaneous
present,
the
more
it shrivels
up
into
something
that
quite
resembles
a
Machian element.
Moreover,
a
bit further
down
you
use
the
term
“content-deficient individual state.”[8]
But
this is
a
completely
incorrect in-
terpretation,
as can
evidently
be
seen
upon adequately
strict
reflection, especially
if
one
considers
that
if
nothing
other than the
momentary
state
existed,
this
state