 To what extent was Kuhn indebted to these thinkers? As noted above, he took Kant but not Hegel very seriously. He was largely self-taught in philosophy of science. Among his contemporaries, he was familiar with Popper but not in any detail with the various strains of logical positivism and logical empiricism, in particular the positions of Carnap and Reichenbach. Apparently, he was only slightly acquainted with the work of Bachelard while writing Structure, and they never engaged in a fruitful interchange (Baltas et al. 2000, 284f). Kuhn did acknowledge, in print and in his classes, the crucial influence on his historical and philosophical thinking of the two Russian émigrés, Émile Meyerson, author of Identité et Realité (1908) and Alexandre Koyré, especially his Études Galiléenes (1939), and that of Annaliese Maier, the German historian of medieval and early modern science. He had read Ludwik Fleck’s Genesis and Development of a Scientific Fact (originally published in German in 1935) and Michael Polanyi’s Personal Knowledge (1958) and had had some discussion with Polanyi (Baltas et al. 2000, 296). Kuhn was also indebted to Wittgenstein, early (“The limits of my language are the limits of my world,” 1922, 148) and late (on language games and forms of life). (See Sharrock and Read 2002, the introduction to Harris 2005, and Kindi 2010 for Kuhn’s relation to Wittgenstein and others.) He knew something of Toulmin’s work.