Drawing Philosophical Lessons from Perrin’s Experiments on Brownian Motion: A Response to van Fraassen

Abstract

In a recent article, van Fraassen has taken issue with the use to which Perrin’s experiments on Brownian motion have been put by philosophers, especially those defending scientific realism. He defends an alternative position by analysing the details of Perrin’s case in its historical context. In this reply, I argue that van Fraassen has not done the job well enough and I extend and in some respects attempt to correct his claims by close attention to the historical details. 1 Science versus Metaphysics 2 Seeking Empirical Grounding for or Testing the Claims of Theories? 3 Atomism and 19th Century Chemistry 4 Perrin’s Experimental Findings: Partitioning and Independent Tests 5 Testing the Kinetic Theory 6 The Status and Significance of the Kinetic Theory after Perrin’s Experiments