A recurrent debate in the IS field has been whether or not IS research should be pluralistic. That is, whether many different forms of research should be allowed, or perhaps even encouraged. This paper presents a review of the literature on pluralism in IS research and analyses the different dimensions and types of pluralism that they adopt. A number of positions towards pluralism in the IS literature are identified and critically assessed. A common theme in this literature is an assumption that different approaches to IS research can be reconciled or even integrated. This is seen as necessary for the credibility of the discipline and to avoid a ruinous decline into relativism. Recent work in the history and philosophy of science, however, has questioned the view that research is, or should be, convergent in this way and offers a more expansive and potentially generative view of pluralism that will be explored in this paper. An argument for “Active Realism” is presented and its implications for IS research discussed.