How to be a type-C physicalist

Abstract

This paper advances a version of physicalism which reconciles the “a priori entailment thesis” (APET) with the analytic independence of our phenomenal and physical vocabularies. The APET is the claim that, if physicalism is true, the complete truths of physics imply every other truth a priori. If so, “cosmic hermeneutics” is possible: a demon having only complete knowledge of physics could deduce every truth about the world. Analytic independence is a popular physicalist explanation for the apparent “epistemic gaps” between phenomenal and physical truths. The two are generally seen as incompatible, since the demon’s deductions seem to presuppose analytic connections between physical and phenomenal terms. I begin by arguing, in support of the APET, that implications from the complete truths of physics to phenomenal truths cannot be a posteriori. Such implications are (according to the physicalist) necessarily true. But they cannot be Kripke-style a posteriori necessities, since (according to the physicalist) the complete truths of physics fix any relevant a posteriori facts about the reference of terms. I then show how the physicalist can turn the tables: the demon can exploit the physical fixing of reference to bridge the gap between the vocabularies, by deducing when phenomenal and physical terms co-refer. This opens the way for a “type-C” physicalism, which accepts in-principle deducibility while still appealing to analytic independence to explain why we (who are not demons) find it impossible to see phenomenal-physical connections a priori.