Islands of Practise and the Marston/Brenner Debate: Towards a More Synthetic Critical Human Geography Mark Purcell This paper argues that an important obstacle to the continued development of critical human geography are ‘islands of practice’, through which scholars become embedded in a research and writing tradition that limits their intellectual and political horizons. I use a recent nondebate in Progress in Human Geography between Sallie Marston and Neil Brenner as an illustration of how islands of practice can stifle intellectual exchange. The paper suggests that the best way to dissolve the islands is a methodological program to create a more synthetic approach that consciously integrates multiple aspects of the critical project.