The aim of this article is to examine ways in which localized research runs the risk of becoming a boundary discourse in a negative sense. The exaggerated emphasis on immanent critique, contextualization and incommensurability may lead discourse and disciplines to an isolationist self-understanding that leaves unchallenged or even entrenches existing discursive hegemonies. Or, it may side with the kind of facile and hasty fusion of discourses and disciplines that ignores epistemic demands and concerns for validity and semantic accuracy. That is, it may overlook the necessity for positively understood discursive boundaries. Clearly demarcated, a-porous boundaries block osmosis and fruitful exchange and facilitate what is called here "stronghold fortification". And they make common cause with a disregard for all boundaries, i.e. with what is called here "frame demolition". Discourses of educational research, and particularly of "special" "versus" "inclusive" education, supply examples that are all the more telling since the very possibility of pedagogy reminds us that relativism is not an option here. To discuss interdisciplinarity and discursivity with an eye to such risks, I refer to Habermas' outlook on the position of philosophy after Kant alongside Derrida's rethinking of the right to philosophy--a rethinking that is grounded in a reading of Kant's cosmopolitical point of view. (Contains 5 notes.)