1. 13 [70] Rudolf Carnap, “Logical Empiricist,” Synthese 25 (1973), 256–68.

2. 14 [89] “Der Wiener Kreis und die Metamorphosen seines Empirismus,” in Norbert Leser, ed., Das geistige Leben Wiens in der Zwischenkriegszeit (Wien: Bundesverlag, 1981), pp. 205–15. Translated by Christian Piller.

3. 15 [106] “Hans Reichenbach Remembered,” Erkenntnis 35 (1991), 5–10.

4. 16 [109] “Empiricism in the Vienna Circle and in the Berlin Society for Scientific Philosophy: Recollections and Reflections,” Scientific Philosophy: Origins and Developments, in Friedrich Stadler, ed., Kluwer (Dordrecht: Academic Publishers, 1993), pp. 1–9.

In the end, Carnap and Neurath had more influence than his Doktorvater, Reichrenbach, on Hempel's thought; and although the interaction with Carnap went on much longer, it was Neurath whose influence proved to be the more enduring. Hempel tells the story here in memorial essays (13, 15) on Carnap and Reichenbach – and in two historical essays (14, 16) in which Neurath figures prominently on the career of logical empiricism.