In moral bioenhancement (MBE) discourse, aggression has been identified as one potential target of biomedical intervention. Early suggestions that aggression might be modulated to improve moral outcomes were met with strong opposition from those claiming it is impossible to modulate aggression without harming traits of distinct social and agential value. If we are to preclude (or endorse) particular paths to moral enhancement then we ought to establish sound reasons for doing so. However, in paying due consideration to contemporary aggression studies (...) we will see that current efforts to rule out aggression as one such path are untenable. I argue that the rejection of aggression-reduction as a viable target of MBE is a mistake, and that this arises from a rudimentary view of aggression which is incompatible with current scientific consensus. Drawing on contemporary psychological views I argue that it is necessary to distinguish subtypes of aggression, and that once these distinctions are recognised there is a potential space for MBE to target the biological correlates of specific kinds of aggressive behaviour. Ultimately, I suggest that aggression remains a legitimate target of inquiry, and that mitigating deleterious manifestations may yet offer one prospect for MBE. (shrink)