Reasons of the heart: emotion, rationality, and the "wisdom of repugnance".

Much work in bioethics tries to sidestep bedrock questions about moral values. This is fine if we agree on our values; arguments about human enhancement suggest we do not. One bedrock question underlying these arguments concerns the role of emotion in morality: worries about enhancement are derided as emotional and thus irrational. In fact, both emotion and reason are integral to all moral judgment.