Tuesday, 1 March 2011
Who Got What Wrong? Sober and F&PP on Darwin: Guide-Principles and Explanatory Models in Natural Selection
José Díez, Visiting Scholar (CPS)
University of Barcelona, Spain
12:05 pm, 817R Cathedral of Learning

Abstract:The goal of this paper is to defend, contra Fodor and Piatelli-Palmarini (F&PP), that the theory of Natural Selection (NS) is a perfectly bona fide empirical unified explanatory theory. F&PP claim that there is nothing non-truistic, counterfactual supporting, of “adaptive” character, and common to different explanations of traits evolution. In his discussion with Fodor, and in other writings, Sober defends NS but claims that this theory has a peculiar epistemic status compared to other theories such as Classical Mechanics (CM): NS explanations contain a priori components not present in CM and other theories. We argue (i) (with Sober and contra F&PP) that there is nothing defective in NS, it provides adaptive explanations of phenotype evolution that share a natural-selection common counterfactual-supporting principle; and (ii) (contra Sober) that there is nothing specifically a priori in NS, adaptive explanations or models—they have no epistemically special a priori status compared to explanations or models in other empirical theories such as CM.
First, we introduce the debate and F&PP’s main strategy. Second, we discuss F&PP’s arguments based on free-riders and show why they are flawed. Third, we show, by reviewing different examples and analyzing Fisher’s model in detail, that NS-explanations of phenotypic evolution share a General Natural Selection Principle. Then, we argue against F&PP’s complaint that such a principle would be a mere truism, and against Sober’s thesis that NS models/explanations have a priori components not present in other common empirical theories. We defend that, regardless of differences in other respects, the NS general principle has the same (subtle) epistemic status as other general principles in other theories, like CM, Thermodynamics or Mendelian Genetics. We conclude that NS is neither defective in F&PP’s sense, nor epistemically “peculiar” in Sober’s sense. Natural Selection is as defective and as epistemically peculiar as Classical Mechanics. The paper also aims to show, by exemplification, how a correct analysis of the structure of theories may help to address substantive epistemological issues.