up the most energizing issues; older positions were squeezed out, not because
they were no longer viable but because there was not room to maintain the
half dozen older factions along with three or four new ones. Neo-Kantianism
was especially vulnerable because, as the dominant German school of the past
two generations, it had crowded the attention space with a variety of sub-po-
sitions. The Neo-Kantians had decentralized themselves in presiding over dis-
ciplinary differentiation, creating meta-topics out of questions of boundary
adjudication. In an opposite spirit were Carnap’s and Neurath’s reductionist
programs for the unification of science. Their physics-centered imperialism was
transitory, but the gesture indicated a deeper thrust of the movement: toward
a radical simplification of the attention space.
The Spillover of Physicists’ Methodological Disputes
The impulse to criticize philosophy is not inherent in physics. The main
previous episode of scientists’ attack had been directed against the interference
of Naturphilosophie, and had subsided when academic autonomy was ob-
tained; the militant materialists of Büchner’s generation had acquired no pres-
tige among philosophers, much less provoking a reform of philosophy from
within such as characterized the twentieth-century analytical schools. On the
contrary, Neo-Kantian philosophers quickly seized on the contradiction that
anti-metaphysical materialists were themselves promoting an uncritical meta-
physics of matter, a critique in which they were joined within science by
Machian phenomenalism. Positivism and Neo-Kantianism were fairly close,
especially in the 1870s and 1880s, in their rejection of materialism; Cassirer’s
philosophy of physics in 1910 was close to Mach’s. And until 1920 Schlick
was arguing for the compatibility of Neo-Kantianism with the phenomenalism
of Mach and Avenarius. How then did smaller points of difference over
post-materialist physics grow into a gulf?
What would become the modern positivist movement started as an internal
development among physicists, laying down methodological rules for their own
discipline rather than legislating generally as to the scope of knowledge or the
practice of philosophy. From the 1870s onward, experimenters in electromag-
netism, light, and radiation formulated mathematical models which dispensed
with depicting the mechanics of physical bodies. A radical movement of physi-
cists led by Kirchhoff and Mach began to argue that concepts such as “mass,”
“force,” and “atom” are merely convenient fictions for simplifying observa-
tions. Mach dismissed theoretical constructs as needless multiplication of meta-
physical entities, even rejecting the existence of natural laws. Ostwald’s vitalist
“energetics” joined forces with the positivists, holding that atoms and matter
can be ruled out by the principle of the economy of thought. On the other side,
The Post-revolutionary Condition^ •^721