Bioconservatism, bioliberalism, and the wisdom of reflecting on repugnance.

We consider the current debate between bioconservatives and their chief opponents--whom we dub bioliberals--about the moral acceptability of human enhancement and the policy implications of moral debates about enhancement. We argue that this debate has reached an impasse, largely because bioconservatives hold that we should honour intuitions about the special value of being human, even if we cannot identify reasons to ground those intuitions. We argue that although intuitions are often a reliable guide to belief and action, there are circumstances in which they are not reliable. Intuitions--including intuitions about enhancement--are subject to various cognitive biases rendering them unreliable in some circumstances. We argue that many bioconservative intuitions about enhancement are examples of such unreliable intuitions. Given this, it is unrealistic of bioconservatives to expect others to rely on their unexamined intuitions. Furthermore, refusing to engage in debates about the reasons and values that underpin their intuitions about enhancement will have the effect of making bioconservative voices less relevant in policy debates about enhancement than they would otherwise be.