In this article, I argue that the history and philosophy of autism need to account for two kinds of autism. Contemporary autism research and practice is structured, directed and connected by an ‘ontological understanding of disease’. This implies that autism is understood as a disease like any other medical disease, existing independently of its particular manifestations in individual patients. In contrast, autism in the 1950s and 1960s was structured by a psychoanalytical framework and an ‘individual understanding of disease’. This implied (...) that autism was not a distinct disease but an idiosyncratic and meaningful response of the child to a disturbed development of the ego. These two kinds of autism are embedded in and reveal two very different ‘styles of psychiatric thought’. (shrink)