International law has a self-determination problem. The paradoxes raised bythe concept, almost like a Russian doll, beget ever more paradoxes. Yet, when pressed forclarity as to its scope, scholars, practitioners, and legal advisers all shy away from precisedefinitions. Based on the apparent collision of competing claims, self-determination is re-duced to a claim to create a new State; territorial integrity is viewed as a necessary protectionfor existing political units. A neat binary is constructed whereby self-determination is reducedto instances where it does not affect territorial integrity (so-called‘internal self-determi-nation’) and those where it disrupts it significantly (‘external self-determination’).The self-determination/territorial integrity binary, though taught widely in internationallaw textbooks, doctrine, and practice, is deceptively simple and fails to tell the whole story; it isfor this reason that we propose a different way of conceptualising self-determination claims ininternational law. In this piece, we will develop an argument that the concept of self-de-termination is in fact a category, a genus, of which there exist four distinct forms, or species:polity-based; identitarian; remedial; and colonial. We argue that by rethinking self-deter-mination in this manner, the common features of these four forms help us further to givecontent to the concept, as well as better to understand the different legal treatment that self-determination claims have received within international law.