Published online by Cambridge University Press: 01 January 2022
I first propose to distinguish between two kinds of external validity inferences, predictive and explanatory. I then argue that we have a satisfactory answer to the question of the conditions under which predictive external validity inferences are good. If this claim is correct, then it has two immediate consequences: First, some external validity inferences are deductive, contrary to what is commonly assumed. Second, Steel’s requirement that an account of external validity inference break what he calls the ‘Extrapolator’s Circle’ is misplaced, at least when it comes to predictive external validity inferences.
I wish to thank Nancy Cartwright for her comments on an earlier draft as well as audiences at the 2014 PSA conference in Chicago and at the UCSD Graduate Philosophy Colloquium.