This paper contributes to the meta-theoretical debate around how best to study regional organizations in an era of increasing dialogue between EU studies and new regioanlism scholars (Laursen 2003; Warleigh-Lack and Rosamond forthcoming; Hettne and Söderbaum 2008). I argue for the return of integration theory as a means of underlining the distinctiveness of regional organizations and their function in the global political economy while creating a conceptual language which enables scholars of all regions to engage with each other. I argue in favour of an evaluative theory approach which maintains the terms ''region'' and ''integration'', but draws on new regionalist understandings of the former while offering a fluid understanding of the latter. I also argue that an evaluative theory approach will help scholars go beyond causal theory to more normative work which helps to analyse the contribution of a region or regional integration in general to the improvement of the general good – which I in turn define by borrowing from Gaia and cosmopolitan theories.