We consider a strategy for justifying bio-conservative opposition to enhancement according to which we should resist radical departures from human nature, not because human nature possesses any intrinsic value, but because it is our nature. The idea is that we can be partial to humanity in the same way that common sense morality allows us to be partial to self, family, lovers, friends or our co…
ersonal autonomy is often lauded as a key value in contemporary Western bioethics, and the claim that there is an important relationship between autonomy and rationality is often treated as an uncontroversial claim in this sphere. Yet, there is also considerable disagreement about how we should cash out the relationship between rationality and autonomy. In particular, it is unclear whether a ra…