Through examining the case of people with epilepsy (which, as we demonstrate, has an ambiguous status in relation to both popular and academic conceptions of disability) we explore the fluid, negotiable and contingent nature of identity and, in particular, the identification as "disabled". Disability, we argue, cannot be reduced to either biology or social oppression, or even primarily to biological or social factors: it is the outcome of a complex interaction between a multiplicity of factors--biological, environmental, social, psychological, cultural and political--which will interact and be experienced differently by different people, at different times and in different situations. Rather than conceiving of disability in "all or nothing" terms and of differing explanations as competing and mutually exclusive, it would be more productive to see them as partial and potentially complementary contributions to the better understanding of a complex and multifarious reality.