DOC.
38 ETHER AND RELATIVITY 181
ETHER
AND
RELATIVITY
23
physics
would become
a complete system
of
thought,
like
geometry,
kinematics,
and the
theory
of
gravitation.
An
exceedingly
ingenious
attempt
in
this
direction has
been made
by
the mathematician
H.
Weyl;
but I do
not
believe
that
his
theory
will
hold
its
ground
in relation
to
reality.
[29]
Further,
in
contemplating
the
immediate
future
of
theoretical
physics we
ought not
unconditionally
to
reject
the
possibility
that
the
facts
comprised
in the
quantum
theory
may
set
bounds
to
the
field
theory
beyond
which
it
cannot
pass.
Recapitulating,
we may say
that
accord-
ing
to
the
general
theory of relativity
space
is
endowed
with
physical
qualities;
in this
sense,
therefore,
there
exists
an
ether.
According
to
the
general
theory of relativity
space
without ether
is
unthinkable;
for
in
such
space
there
not
only
would
be
no
propagation
of
light,
but
also
no
possibility
of
existence for
standards
of
space
and
time
(measuring-rods
and
clocks),
nor
there-
fore
any
space-time
intervals
in
the
physical
sense.
But this ether
may
not be
thought
of
as
endowed with the
quality
characteris-