This chapter seeks to advance two central claims: 1) that the therapy-enhancement distinction is not an absolute one; and 2) that the social model of disability can be applied as at least one possible criterion for evaluating the ethics of enhancement. First, I address the limits of the therapy-enhancement distinction by showing that some accepted forms of therapy are indeed enhancements in their own right. The line between enhancement and therapy in medicine is therefore not clear-cut, but nor is the difference between enhancement and disability straightforward either, as I argue. I discuss how some forms of apparent enhancement may in fact make people disabled from a social point-of-view, for they would not be able to function well in a society “fine-tuned” towards the current average range of abilities. Enhancement is therefore a slippery notion, and one that brings into relief questions of equity and of oppression. If enhancement is meant to be a key stepping stone on the path towards a posthuman condition, as some claim, then the ambiguous nature of enhancement surely throws into the question the coherence of the “post” in “posthuman.”