334
DOCS. 343-345
MAY 1917
given can
be
an illusion,
what
is
spatio-temporally
classified
can
be
a
sterile
concept
contributing nothing
toward
illuminating
the
connections
with what
is
immediately
given.
I
would like to
suggest a
clear
conceptual
distinction
here.[5]
Best
regards, yours,
A.
Einstein.
344. To
Paul Ehrenfest
[Berlin,]
25
May
1917
Dear
Ehrenfest,
Don’t
swear
at
me
for
answering your
kind
invitation
card
only
now!
Unfortu-
nately,
I
cannot
think
of
a
trip
to Holland
for
now.[1]
At
the
beginning
of
July
I’m
going
to Switzerland
to
see
my
children. The
little
one
is
very sickly
and must
go
to Arosa
for
1 year.[2]
I’m
going
to
go
there
with Albert.
My
wife is
also
ailing.[3]
Worries and
more
worries.
Nonetheless,
I
have found
a
nice
generalization
of
the
Sommerfeld-Epstein
quantum law.[4]
Droste’s
dissertation
is
extraordinarily
fine.[5]
This
man
must
get a proper
position
soon.[6] I
should discuss
the
relativity
of
inertia, etc.,
urgently
with de
Sitter
and
you;[7]
but it
is
no good
in
writing.
My
health
is
in decent
shape,
but
I
have to
follow
a
strict
diet.[8]
Pardon
my
scribblings
to
you
here and cordial
regards
also to
your family, yours,
Einstein.
345.
From Max Planck
[Berlin,]
26 May
1917
Dear
Colleague,
If
anything
had
been able
to
entice
me
yesterday
to
the
Physical Society,
it
would have been
the
suggestion
you relayed
to
my daughter[1] by telephone.
However,
I
must tell
you
that
I
still
feel
physically incapable
of work these
days.
I
can
take
only
absolute necessities in
hand.
My grief
over
my
second
daughter,[2]
who
passed away
in
my
arms
last
week
from
pulmonary
embolism,
still
gnaws
too
persistently
at
my
thoughts
for
them
to be
able to exert
their normal
freedom of
action. After Pentecost
it
will
improve
again.
Until
then,
please
make allowances
for
your
devoted
colleague
M.
Planck
I
console
myself
with
the
thought that,
if subelectrons
really
do
exist, they
will
also
make themselves noticed otherwise
than in
the
lecture I
had
to
miss.[3]