Where?, I hear you asking. No, that is the title of a new book by Karl Sigmund and the subtitle is The Vienna Circle and the Epic Quest for the Foundations of Science. I enjoyed this book very much, though I don’t recommend it as a balanced introduction to its chosen topic. I liked it best for its whims and interstices:

1. The mathematician Richard von Mises (brother of economist Ludwig) was a patron of Rilke, and he established a foundation for the sole purpose of supporting Robert Musil.

2. Carl Menger was planning on writing a philosophical treatise, and one which would have had a “Vienna Circle” anti-metaphysical slant.

3. Arguably Karl Popper learned the most from a polymathic cabinetmaker he was apprenticed to in his youth.

4. Friedrich Wieser had supported Mussolini, but a young Oskar Morgenstern, in his diary, complained that Wieser was too liberal.

5. Morgenstern later became a confirmed liberal, and he also remarked a few times that game theory was for the social sciences completing the research program of Kurt Gödel.

6. Karl Popper complained that Wittgenstein threatened him, in a lecture, with a poker. It is not obvious this was the case.

7. I came away from my read wanting to sample more Ernst Mach, more Moritz Schlick, and thinking Otto Neurath was perhaps badly underrated.

Note that most of the book is more serious than this, and less concerned with economists, much more with math and science and some psychoanalysis and positivism too.