INTRODUCTION TO VOLUME
6
xvii
paper
which transformations
were
allowed
by
the
theory. Introducing
the
ter-
minology
of
"adapted
coordinate
systems"
and
"justified
transformations"[7]
for the frames in which the
theory
was
valid and for the transformations
con-
necting them, they
succeeded in
deriving
a
condition which all
justified
trans-
formations had
to
fulfill.
They
also claimed without
explicit
proof
that the al-
lowed transformations included
accelerations.
In
a lengthy
and
complicated paper published
in November
1914
(Einstein
1914o
[Doc.
9]),
the
theory
is
developed
in
a systematic
way,
starting
with
a
detailed
exposition
of
tensor calculus.[8]
The derivation of
the
field
equations
is
preceded by
a new
version
of
the "hole
argument"
to
show
that
the
equa-
tions
describing
the
processes
in
a
gravitational
field
"cannot
possibly
be
generally
covariant."[9]
As in Einstein and Grossmann 1914b
(Doc.
2),
a
vari-
ational
principle
is
the
starting
point
for the derivation of
the field
equations,
but
in contrast to
the earlier
paper,
in
which the form of
the
Hamiltonian
was
specified
from the
outset,
Einstein
now
formulates
general
conditions from
which the
explicit
form of the Hamiltonian
is
then derived. It
turns out
that
the Hamiltonian obtained
in
this
way gives
rise
to
the
"Entwurf"
field
equa-
tions. As Einstein concludes: "We
now
have arrived
at
very
definite
field
equations
in
a
purely
formal
way,
i.e.,
without
drawing directly
on our
phys-
ical
knowledge
of
gravitation."[10]
A
year
later Einstein had
changed
his mind
completely.
The
story
of how
he
struggled
with the
theory during
this
year
until
he
came
to
the conclusion
that it had
to
be abandoned has been told
many
times and will
only
be
reca-
pitulated
here.[11]
Not much
contemporary
material
is
available
to reconstruct
Einstein's
thinking during
that
year,
and
we
have
to rely
to
a
large
extent
on
Einstein's
own
statements
made
on
various later occasions. From the avail-
able documents it
appears
that
by
the fall of
1915
Einstein had become
aware
of three
major
flaws
in the
theory:[12]
the
argument
used in Einstein 1914o
(Doc.
9)
to fix
the Hamiltonian
was
wrong;
the
theory
was
not
covariant for
[7]"angepaßte
Koordinatensysteme"
and
"berechtigte
Transformationen,"
respectively.
[8]See
Norton 1984 for
an
extensive discussion of this
paper.
[9]"unmöglich
allgemein
kovariant sein können." Einstein 1914o
(Doc. 9),
p.
1066
(Ein-
stein's
emphasis).
[10]"Wir
sind
nun
auf rein formalem
Wege,
d. h.
ohne direkte
Heranziehung unserer physi-
kalischen Kenntnisse
von
der
Gravitation,
zu
ganz
bestimmten
Feldgleichungen gelangt."
Ein-
stein 1914o
(Doc. 9),
p.
1076.
[11]See,
in
particular,
Earman and
Glymour
1978a;
Pais
1982,
chap. 14;
Norton
1984;
and
Stachel 1989.
[12]They
are
listed
in two
letters: Einstein
to
Arnold
Sommerfeld, 28
November
1915,
and
Einstein
to
H. A. Lorentz,
1
January
1916.
The
first two
are
also mentioned
in Einstein
1915f
(Doc. 21),
p.
778.