In the context of  ‘complex emergencies and military humanism a number of disputes have occurred regarding the nature and purpose of humanitarian action and its relationship to other desirable goals. In particular the emergence of a humanitarian discourse of rights defense and a practice of integration with other actors, has challenged the traditional role of the ICRC.   The twists and turns of humanitarianism prompt investigation into the foundations and principles underlying it.  The crisis of traditional Humanitarianism and the costs of the new Humanitarianism have left many looking for a new guiding principle or ‘moral banner’ (Fox 2002). This paper examines three understandings of the nature of humanitarianism, its meaning and its moral justification. Humanitarianism as Charity, Humanitarianism as Rights defense and humanitarianism as mutual aid, or beneficence.  Of these three only the first have received any sustained attention in the literature, The third while well understood in philosophical discourse has not been applied to the practices of humanitarian actors.  The remainder of this paper suggests that a Kantian reading of the doctrine of mutual aid can help provide not only a ‘moral banner’ but a more satisfactory moral foundation for the Humanitarian project which helps to overcome some of the limitations of classical, human rights and new Humanitarianism.