Does the heterogeneity of autism undermine the neurodiversity paradigm?

The neurodiversity paradigm is presented by its proponents as providing a philosophical foundation for the activism of the neurodiversity movement. Its central claims are that autism and other neurodivergent conditions are not disorders because they are not intrinsically harmful, and that they are valuable, natural and/or normal parts of human neurocognitive variation. This paper: (a) identifies the non-disorder claim as the most central of these, based on its prominence in the literature and connections with the practical policy claims that the paradigm is supposed to support; (b) describes the heterogeneity of autism at the behavioural and causal levels, and argues that at the behavioural level this encompasses ways of being autistic that are harmful in ways that cannot be not wholly attributed to discrimination or unjust social arrangements, challenging the claim that autism is not a disorder; (c) considers and rejects responses to this challenge based on separation of high- and low-functioning autism, separation of autism from co-occurring conditions, and viewing autism as part of an individual's identity. Two of these responses fail for reasons that are themselves connected with the behavioural and/or causal heterogeneity of autism.