LAUSR

Summary Psychotic phenomena include a far wider range of experiences than is captured by the brief descriptions offered in contemporary diagnostic guides. Given the richness of historical clinical phenomenology, what can account for the recent ascendancy of relatively impoverished descriptions of psychosis? One possible explanation is provided by Hacking's notion of dynamic nominalism, where human categories change over time in tandem with those who they classify. But although dynamic nominalism makes sense of changes in behaviour, it fails to account for change at the level of subjective experience. In this paper, psychotic symptoms are addressed in the light of the indeterminacy of subjective mental content. A naïve-introspectionist approach to mental symptoms assumes that, notwithstanding practical difficulties, such symptoms are reliably describable in principle. Contemporary philosophy of mind challenges this assumption. Lighting upon a verbal description for ineffable phenomena changes their nature, resolving them into new forms. Declaration of interest None.