This chapter focuses on Hans Kelsen's critique, as laid out in the 1922 book, of Max Weber's definition of the State. Kelsen's book aims to give ‘critical proof of the identity of the State and law’. This critique ultimately comes down to challenging the possibility not only of a sociology of the State, but also of a sociology of law, or even, generally speaking, the very possibility of sociology as a science. The chapter highlights a particularity of sociological concepts of collectives: their relative indeterminacy. Kelsen's analysis begins with a comment on Weber's definition of interpretive sociology. The second part of the analysis focuses more specifically on the ideal type of the State that is, its 'essence’. In a third section, Kelsen reviews the various types of social relationships that Weber distinguishes and defines in ‘Basic Sociological Terms’. Kelsen concludes that, for normative orders, interpretive sociology has no concepts at its disposal other than those used by legal theory.