The chapter introduces a distinction between two kinds of concepts used in discursive practices in the area of law: object-concepts and tool-concepts. The distinction, rooted in Brandomian analytic pragmatism, is based on the idea that the vocabulary of tool-concepts is best understood as an element of pragmatic meta-vocabulary relation with regard to the vocabulary of object-concepts in law. The historical part advances the claim that the emergence of fully developed tool-concepts resulted from a revolutionary turn in medieval glossators’ improvement of understanding of their own techniques. The theoretical part of chapter elaborates on the distinction and examines its theoretical benefit of extending the analysis of concepts in law beyond the confines of relations between vocabularies. This offers a shift of focus from words or vocabularies to practices or abilities that the users of such concepts engage in and must possess.