Abstract

In this paper I argue that two claims usually included in any minimally detailed presentation of the epistemic closure principle are inconsistent, namely, that closure explains how we extend our knowledge through deduction and that it is different from another epistemic principle, to wit, transmission. The attempt to offer a correct diagnosis of reasonings such as the one involved in Dretke’s zebra case is an instance of a discussion in which the distinction takes part. My argument has the following structure. First, I introduce the distinction between closure and transmission following the standard presentation. Second, I introduce the main motivations behind the principles; in particular, I establish that the main motivation behind closure consists in explaining the phenomenon of the advancement of knowledge through deductive reasoning. Third, based on the identification of a restriction on any plausible formulation of closure capable of explaining the phenomenon aforementioned, I cast doubts on the distinction between this principle and transmission. I conclude that any formulation of the epistemic principle of closure which satisfies its main motivation collapses into the epistemic principle of transmission.