 Carnap’s first exposure to logic came from an obscure and reclusive professor of mathematics at Jena, Gottlob Frege. Carnap was so fascinated that he took every course Frege offered (including two courses on Frege’s Begriffsschrift and a course on Logic in Mathematics). His resulting shorthand notes are sufficiently detailed to permit a reconstruction of Frege’s response after the system of the Grundgesetze had been undermined by Russell’s paradox (Reck &amp; Awodey 2005). It would be another decade, though, before Carnap came to see Frege’s logic as the key to a new way of doing philosophy. Carnap also studied with neo-Kantians and Lebensphilosophen, including Bruno Bauch (whose course on Kant’s First Critique left a lasting impression), Herman Nohl (a student of Dilthey) and—while in Freiburg for a semester—Heinrich Rickert, whose lectures Carnap was particularly enthusiastic about. 