Recent developments in the science of autism have provoked widespread unease among autism activists. Drawing on the findings of a major international gathering of researchers, ethicists, and activists, this paper presents the first major analysis of the ethical questions arising from this unease. We outline the scientific developments that have provoked the most discomfort, analyze the response to these developments from within and without the autism community, and trace the current state of the ethical debate. Having done so, we contend that these ethical questions are unlikely to be resolved as they depend on fundamentally conflicting assumptions about the nature and desirability of neurocognitive difference. We conclude by arguing for a new range of democratic mechanisms that could enable the scientific community, autistics, and other concerned parties to respond collectively to such entrenched ethical disputes. Autism Res2011,4:271–282. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.