cial justice, physics—each has its underlying logic. Psychologists too spotted
logic as an old and stagnant field ripe for reform by new scientific methods.
Brentano launched his Psychology from an Empirical Standpoint in 1874,
which transforms all propositions into acts of judgment in empirical conscious-
ness.^6 Brentano attempted to eliminate deductive, a priori logic and replace it
with purely empirical judgments about objects. In the next year Wundt estab-
lished the first psychological research laboratory, and touted psychology as an
experimental science which would become the basis of all the human sciences
and of philosophy as well. Logic was to be founded on scientifically discovered
structures of the human psyche. Another branch of inductivist logic made
inroads in Germany by import. A militant scientific movement in England had
led the intellectual opposition to the unreformed religious universities; in the
person of J. S. Mill, it took on the scholastic logic and proposed to replace it
with a logic of empirical induction.
Frege’s creativity was sparked by opposition to these movements. In his
writings his principal foil is Mill and the latter’s German followers; as psy-
chologism flourished in the 1880s and 1890s, Frege’s anti-psychologism grew
more pointed. Frege saw a very different logic opening up from the mathe-
matical controversies now coming to a head, owing to his position in the
mathematical network as well as the philosophical one. As a student Frege had
heard Lotze and had studied mathematics at Göttingen, the great center of
German mathematics, where Riemann produced his generalizing work on
non-Euclidean geometry in the 1850s. Frege became a friend of Cantor, nearby
at Halle, already embattled in his struggle against the conservative mathema-
ticians; it was Cantor’s tools that Frege developed.
In 1879 Frege formulated in his Begriffsschrift (conceptual notation) the
first comprehensive or general logic (Kneale and Kneale, 1984: 510–511;
Coffa, 1991: 69–71). Traditional logic descending from Aristotle (what would
now be called primary logic) was restricted to classifying various kinds of
propositions. To some extent Stoic and medieval scholastic logic had gone on
to formulate general principles underlying valid propositional inference; in the
more general arena, Leibniz and later Boole had developed the aspects of logic
concerned with attributes or classes. Frege parted company with logic in the
form of subjects and predicates, of “all A’s are B’s.” Ordinary language hides
the crucial distinctions and elevates merely grammatical differences obscuring
the underlying content. The lineage of ancient Greek logic, institutionalized in
late antiquity in alliance with the profession of grammarians and continued in
the curriculum of the medieval universities, was now displaced by the imperi-
alism of mathematical methods. Modern mathematics arose around 1600 by
breaking with verbally formulated geometry, and developing instead the new
technical format of variables and functions in one area after another. The
The Post-revolutionary Condition^ •^701