In the sociology of science, paradigms are a bit like castles. Scientists are knights in this metaphor, and assumptions are the liege-lords that the knights/scientists are sworn to defend. The strength of a paradigm can be measured by how many scientists are willing to defend its ramparts. Scientists tend to retain allegiance to their assumptions, so that the paradigmatic castles defend their inhabitants successfully, until those inhabitants die off. In this metaphor, it is in the nature of paradigms to be mutually exclusive – as a knight/scientist, one is more concerned about defending one's castle/paradigm, and in defeating others, than in building bridges among them. Paradigms, in other words, are distinct from, and in opposition to, each other.

This view of paradigms has been regularly co-opted in discussing both the sociology and the epistemology of international relations as a discipline. Thomas Kuhn's seminal discussion of paradigms and the sociology of science is regularly taught in graduate international relations theory courses, despite Kuhn's suggestions that his argument does not necessarily apply to social science. Whether or not one accepts Kuhn's argument about the sociology of the natural sciences, and whether or not one sees paradigms in the social sciences as being equivalent to those in the natural sciences, it remains the case that the language of paradigms pervades thinking about international relations theory.