Abstract The only biologically respectable notion of human nature is an extremely permissive one that names the reliable dispositions of the human species as a whole. This conception offers no ethical guidance in debates over enhancement, and indeed it has the result that alterations to human nature have been commonplace in the history of our species. Aristotelian conceptions of species natures, which are currently fashionable in meta-ethics and applied ethics, have no basis in biological fact. Moreover, because our folk psychology (...) finds this misleading Aristotelian conception highly tempting, we are in fact better off if we refrain from mentioning human nature altogether in debates over enhancement. Content Type Journal Article Category Special Issue Pages 1-16 DOI 10.1007/s13347-012-0063-x Authors Tim Lewens, Department of History and Philosophy of Science, University of Cambridge, Free School Lane, Cambridge, CB2 3RH UK Journal Philosophy & Technology Online ISSN 2210-5441 Print ISSN 2210-5433. (shrink)