Abstract

Overlapping consciousness is when a system with (unified) consciousness has parts that also have (unified) consciousness. A number of theories of consciousness clearly imply or raise the possibility of such overlap, including functionalism, panpsychism and some accounts of split-brain cases. In neuroscience, most theories also posit correlates of consciousness that will overlap with smaller or larger versions of themselves, thus implicitly implying overlap as well. An exception is the Integrated Information Theory, which explicitly prohibits overlap via its Exclusion postulate, but this postulate has been widely criticized as poorly supported. I develop an argument against overlapping consciousness, according to which given the arguably most plausible view of the nature of subjects, the deflationary bundle view, overlap would entail a straightforward contradiction. Given the arguably less plausible substantive view of subjects, overlap is possible but it would still be highly unparsimonious. Any theory that implies overlap should therefore be rejected or modified to exclude it after all.