This paper aims to analyze technical and internal aspects of one particular type of human moral enhancement, i.e. enhancement of moral motivation via direct emotion modulation. More precisely, it challenges the assumption that modifying certain emotions will have the results desired by the advocates of this theory. It is argued that neuropsychological understanding of the role and function of emotions, as well as of underlying cognitive mechanisms, might be relevant for the discussion about biomedical enhancement of moral capacities. Moreover, typical (...) claims about direct emotion modulation seem to be contradicted, or at least seriously challenged, by available neuroscientific data. Particular attention is paid to the theory that emotions are evolved and functionally specialized programs whose task is to coordinate other adaptive mechanisms of human psychology in order to promote one’s fitness. If this view of emotions is plausible, it can be argued that several difficulties for moral bioenhancement theory ensue. Neuroscientific and evolutionary-psychological perspective seem to indicate that emotions don’t fulfill necessary requirements to serve as the vehicles of moral enhancement and it should, therefore, take into account role and function of entire cognitive modules associated with moral decision-making. (shrink)