Interdisciplinarity is a notoriously difficult concept to define, and even harder to achieve in practice. All too often social approaches reduce science to an object of study, or conversely physical science approaches are invoked as a source of 'higher' truth. Drawing upon our experiences as ESRC-NERC PhD students within geography, we outline a paratactical approach that links disciplines by adjacency rather than hierarchy. Toppling the disciplinary hierarchy creates the potential for non-reductionistic dialogue between science and social science, but it also (...) raises a series of practical difficulties. These are considered around the themes of polyvocality, breadth over depth and (im)permanence. We suggest that while this kind of approach is increasingly encouraged by research funding bodies, it is less easily sustained within the everyday mechanics of the academic world. (C) 2006 Elsevier Ltd. All rights reserved. (shrink)