The emerging interdisciplinary work in language politics and language policy and planning studies demonstrates a rising interest among researchers in the interface between sociolinguistics, political science and philosophy. Much of the resulting cross-disciplinary work, however, tends to focus on the subject matters (politics, language) themselves rather than explore the broader issues that transpire from working in the interface between distinct fields of academic inquiry. Reflecting on the meaning of interdisciplinary work in LPP, I examine the interface and internal fences between sociolinguistics and political philosophy as fields of inquiry. I then move on to consider the way(s) in which "thinking linguistically" and "thinking politically" may be advantageously combined in the fundamentally interdisciplinary terrain of normative language policy.