INTRODUCTION
TO
VOLUME
2
xxvii
but
should be
constructed,
emerging
from
a satisfactory theory
of
matter and
radiation. He
anticipated
that
"the
same
modification
of
the
[Maxwell-Lorentz]
theory
which contains the
elementary quantum
[of
electricity]
will also
contain
the
quantum
structure
of radiation"
("die
gleiche
Modifikation
der
Theorie, welche
das
Elementarquantum
als
Konsequenz
enthält,
auch die
Quantenstruktur
der
Strahlung
als
Konsequenz
enthalten
wird").[63]
In 1909 Einstein made his first known
attempt
to find
a
field
theory
that would
explain
the structure
of
both matter and radiation. After
investigating
relativisti-
cally
invariant,
nonlinear
generalizations
of Maxwell's
equations,
he wrote:
I have
not
yet
succeeded
. . .
in
finding a system
of
equations
that
I
could
see was
suited to the construction
of
the
elementary quantum
of
electricity
and the
light quantum.
The manifold
of
possibilities
does not
seem
to be
so large, however,
that
one
should shrink from the task.
Es ist mir noch nicht
gelungen,
ein
. . .
Gleichungssystem zu finden,
von
dem
ich hätte einsehen
können,
daß
es
zur
Konstruktion des elek-
trischen
Elementarquantums
und der
Lichtquanten
geeignet
sei. Die
Mannigfaltigkeit
der
Möglichkeiten
scheint aber nicht
so
groß
zu sein,
daß
man vor
der
Aufgabe
zurückschrecken
müßte.[64]
The
attempt
to
find such
a system
of
equations
constitutes
a
forerunner
of
his later
search
for
a
unified field
theory.
Of
course,
the search for
a
unified theoretical foundation for all
of
physics
did
not
originate
with Einstein.
During
his formative
years as
a
physicist,
three such
foundational
programs
were
current,
each with
universal,
and hence exclusive,
ambitions: the traditional
program
based
upon
classical mechanics, the
energetics
program
based
upon thermodynamics,
and
the
electromagnetic program
based
upon
Maxwell'
s theory.[65]
Einstein
was apparently
attracted
to
the idea
of
a
uni-
fied foundation
for all
of
physics quite early
in his
career.[66]
While he does
not
appear
to have been attracted
by
the
energetics
program,[67]
he
was
profoundly
[63]
Einstein
1909b
(Doc. 56),
pp.
192-193.
[64]
Einstein 1909b
(Doc. 56),
p.
193.
[65]
For
a
survey
of
these three
programs, see
Jungnickel
and
McCormmach
1986b, chap. 24,
pp.
212-245.
[66]
In
1901,
in
commenting on
his first
paper,
Einstein wrote:
"It
is
a
glorious feeling to
rec-
ognize
the
unity
of
a
complex
of
phenomena,
which
appear
to direct
sense perception as quite
distinct things" ("Es ist ein herrliches
Gefühl,
die
Einheitlichkeit
eines
Komplexes
von
Er-
scheinungen zu
erkennen,
die
der
direkten sinn-
lichen
Wahrnehmung
als
ganz getrennte Dinge
erscheinen")
(Einstein to
Marcel
Grossmann,
14
April
1901,
Vol.
1,
Doc.
100).
Einstein
may
have
picked up
this theme from
Humboldt's
Kosmos,
which
he
is
reported to
have
read
as a
youth
(see note 8 to ibid.).
[67]
In
1913,
he endorsed
Planck's
judgment
(see
Planck
1896)
"that
energetics
is worthless
as a
heuristic
method, indeed,
that it
even oper-
ates with untenable
concepts"
("daß die Ener-
getik
als heuristische Methode wertlos
ist, ja,
daß sie
sogar
mit unhaltbaren
Begriffen oper–