Rudolf Carnap, Otto Neurath, John Von Neumann, Marguerite Young, Max Black, Herbert Feigl, Reinhardt Grossmann, Erwin Tegtmeier, Philipp Frank, Herbert Hochberg, Wilfrid Sellars, Alexius Meinong, Adolf Grünbaum, Gustav Bergmann, William Henry Hay, William Smith Heald, Edwin Bonar Allaire, May Brodbeck, Rosaria Egidi, Alan Michael Hausmann
Philosophers discussed include Franz Brentano, Kurt Gödel, and Ludwig Wittgenstein. Correspondents include May Brodbeck, Herbert Feigl, John von Neumann, and Marguerite Young.