In this article I discuss Kant's idea of cosmopolitanism both in its prescriptive dimension (its normative content and regulative aspirations) and also its descriptive basis (its crucial philosophical-anthropological assumptions constituting its theoretical justification). My aim is to show that the prescriptive dimension cannot be treated separately from the descriptive one for some difficulties that the latter confronts pervade the former and misinform it. I then proceed to an examination of those difficulties which I locate mainly in Kant's onto-theological commitment to (...) some anthropological tenets of his era. I explore the implications of these tenets and show that they contribute negatively to the task of the promotion of a cosmopolitanism that respects difference and heterogeneity. I conclude with some critical suggestions pro-pounding a renegotiation of the paradigmatic certainties of Kant's cosmopolitanism in order to salvage its normative import and couch it in less onto-theological terms. (shrink)