What Carnap might have learned from Weyl

Thomas Ryckman (Stanford) gives a talk at the MCMP workshop "Influences on the Aufbau" (1-3 July, 2013) titled "What Carnap might have learned from Weyl". Abstract: There are easily discernible traces of the influence of Hermann Weyl in the writings of Carnap in the early to mid- 1920s. It is somewhat more difficult to find any palpable influence of Weyl in the Aufbau. On the other hand, Weyl’s 1926 Philosophie der Mathematik und Naturwissenschaften is the sole work singled out in Aufbau's Bibliography as “especially suitable for study of problems connected with construction theory” in both the “logical” and the “epistemological” categories. I shall argue that, in the crucial Aufbau passage (§176) “demonstrating” the non-constructability of the reality (as mind- transcendent) concept, Carnap may have had §17 of Weyl’s 1926 book very much in mind.