Both support and attack are essential concepts in natural argumentation. As originally introduced, however, abstract argumentation considered only attack. Although there have been attempts to add a support relation to abstract argumentation, these do not fulfil all desiderata. In this paper we show how the various notions of necessary and sufficient support can be captured using only the attack relation, and highlight the problematic nature of the notion of general support. We suggest that leveraging abstract argumentation semantics and the attack relation to represent support, and the consequent expression of argument in a simple graphical architecture, will yield computational benefits
