Expanding Our Grasp: Causal Knowledge and the Problem of Unconceived Alternatives

Abstract

I argue that scientific realism, insofar as it is only committed to those scientific posits of which we have causal knowledge, is immune to Kyle Stanford’s argument from unconceived alternatives. This causal strategy (previously introduced, but not worked out in detail, by Anjan Chakravartty) is shown not to repeat the shortcomings of previous realist responses to Stanford’s argument. Furthermore, I show that the notion of causal knowledge underlying it can be made sufficiently precise by means of conceptual tools recently introduced into the debate on scientific realism. Finally, I apply this strategy to the case of Jean Perrin’s experimental work on the atomic hypothesis, disputing Stanford’s claim that the problem of unconceived alternatives invalidates a realist interpretation of this historical episode. 1 Stanford’s Argument from Unconceived Alternatives2 Previous Attempts to Undermine the Problem of Unconceived Alternatives 2.1 The plausibility of unconceived alternatives 2.2 The distinctness of unconceived alternatives 2.3 The induction from past to present3 Causal Knowledge as a Criterion for the Realist 3.1 How Chakravartty’s proposal differs from earlier causal strategies 3.2 Causal realism and the detection/auxiliary distinction4 Causal Realism, Unconceived Alternatives, and the Atomic Hypothesis 4.1 Perrin and the philosophers: some initial observations 4.2 Roush and Stanford on Perrin 4.3 From Brownian motion to the reality of atoms 4.4 What we know about atoms5 Conclusion