IR constructivism maintain that a proper understanding of the way subjects interact with the world and with each other alerts us to the fallacy of conventional IR theory. And yet, for a theory that is so obviously dependent upon a rigorous working of the relationship between social theory and its IR variant, it is curious that, with one or two exceptions, IR constructivists often advance incompatible theories. I argue that the confused manner by which, in particular, ‘soft’ constructivism relates to social theory is not accidental but a necessary component of a theory that asserts, but never proves, the primacy of norms and laws over material considerations, in domestic and international politics.