A Simple Theory of Introspection

This chapter develops a simple theory of introspection, according to which one has introspective access to the fact that one is in a certain mental state just by virtue of being in that mental state. This raises two questions. First, there is a generalization question: which mental states are introspectively accessible? And second, there is an explanatory question: why are some mental states introspectively accessible, rather than others, or none at all? In response to the generalization question, the chapter argues that a mental state is introspectively accessible if and only if it is phenomenally individuated. And in response to the explanatory question, the chapter argues that a mental state is introspectively accessible if and only if it is among the determinants of justification. This provides the basis of an argument for a phenomenal conception of justification, according to which a mental state is among the determinants of justification if and only if it is phenomenally individuated.