Abstract :
While Saunders Mac Lane studied for his D.Phil inG¨ ottingen, he heard DavidHilbert’s
weekly lectures on philosophy, talked philosophy with Hermann Weyl, and studied it
with Moritz Geiger. Their philosophies and Emmy Noether’s algebra all influenced
his conception of category theory, which has become the working structure theory of
mathematics. His practice has constantly affirmed that a proper large-scale organization
for mathematics is the most efficient path to valuable specific results—while he sees
that the question of which results are valuable has an ineliminable philosophic aspect.
His philosophy relies on the ideas of truth and existence he studied in G¨ ottingen. His
career is a case study relating naturalism in philosophy of mathematics to philosophy
as it naturally arises in mathematics.
