Abstract

The so-called unity of consciousness consists in the compelling sense we have that all our conscious mental states belong to a single conscious subject. Elsewhere I have argued that a mental state's being conscious is a matter of our being conscious of that state by having a higher-order thought (HOT) about it. Contrary to what is sometimes argued, this HOT model affords a natural explanation of our sense that our conscious states all belong to a single conscious subject. HOTs often group states together, so that each HOT is about a cluster of target states; single HOTs represent qualitative states as spatially unified and intentional states as unified inferentially. More important, each HOT makes one conscious of oneself in a seemingly immediate way, encouraging a sense of unity across HOTs. And the same considerations that make us assume that our first-person thoughts all refer to the same self apply also to HOTs; becoming conscious of our HOTs in introspection thus leads to a sense that our conscious states are unified in a single self. I argue that neither essential-indexical reference to oneself nor the alleged immunity to error through misidentification conflicts with this account. I close by discussing the apparent connection of unity with free agency