Abstract

Taking (a proposition) to be true is an epistemic theme appearing throughout George E. Smith’s work; this includes his marvelous new book with Raghav Seth, Brownian motion and molecular reality: A study in theory-mediated measurement (2020; hereafter Smith and Seth). They use this notion to categorize changes in scientific perspectives both towards the ontological claim that molecules exist and towards molecular-kinetic theory. They illustrate the shift in viewpoint occurring over the successive editions of Ostwald’s and Nernst’s respective textbooks. Nernst writes, in his 6th edition, that, “the theory begins to lose its hypothetical character”; later he writes, “… we may well acknowledge that the theory has lost its hypothetical character” (Smith and Seth, 3). Ostwald does an “about-face on atomism” (2): In earlier editions he characterizes the “atomic conception” as a “convenient mode of representation,” as having “enormous heuristic value” (2). In the 4th edition (1909) he writes (2)