The Tacking by Disjunction Paradox: Bayesianism Versus Hypothetico-Deductivism

Hypothetico-deductivists have struggled to develop qualitative confirmation theories not raising the so-called tacking by disjunction paradox. In this paper, I analyze the difficulties yielded by the paradox and argue that the hypothetico-deductivist solutions given by Gemes [1998, Erkenntnis 49, 1–20] and Kuipers [2000, From Instrumentalism to Constructive Realism, Kluwer, Dordrecht] are questionable because they do not fit such analysis. I then show that the paradox yields no difficulty for the Bayesian who appeals to the Total Evidence Condition. I finally argue that the same strategy is unavailable to the hypothetico-deductivist.