Autism spectrum conditions represent a broad range of behavioral, cognitive, and neurological atypicalities. As both a social and a medical category, autism is dynamic and unstable, and, although its usefulness is rarely contested, its ontological status is frequently under debate. Scholars who write about autism face the challenge of accepting the category as valuable without reifying it as one that corresponds unambiguously with a uniformly atypical brain structure. An approach to autism is, therefore, needed that acknowledges both its biological and social components and that embraces the inevitable contingency and mutability of knowledge about the condition. Drawing primarily on literature from anthropology, I argue that autism can be said to act in the world only insofar as it affords us a template, a system of meanings and significations with which to classify bodies, make sense of events and allow for an increasingly nuanced understanding of diverse behaviors, tendencies and motivations. Thus, the category of autism emerges from the shared experiences of those labeled autistic, but is wholly irreducible to them. A significant implication of this approach is a view of autism and autistic people as two conceptually distinct entities.