ABSTRACT The aim of this essay is to question the coherence of debates on moral enhancement by neurophysical or pharmaceutical means in the absence of a cogent conception of the object of moral scrutiny: namely, moral enhancement. I present two conceptions of moral enhancement—weak and strong—and argue that given the problem of acquiring a standard measure of moral enhancement, regardless of whether enhancement is present in its weak or strong form and regardless of whether one endorses moral realism or different (...) forms of antirealism, presenting a cogent conception of moral enhancement is fraught with difficulty. This fact has serious implications for continuing debates on the morality of moral enhancement, insofar as it limits the extent to which we have, or it is possible to have, an agreed conception of moral enhancement that could be empirically verified and count as an object for moral scrutiny. (shrink)