Legalism is as much about cultures of argument as it is about ‘rule following’. This chapter first explores the conceptual make-up of legalism through an analysis of Rudolph von Jhering’s attack on Begriffsjurisprudenz (the ‘jurisprudence of concepts’), before turning to Jhering’s own sociological jurisprudence. The following section analyses the temporality, particularity, and constructedness of legal rules and concepts, taking Hart’s analytical jurisprudence as a focus. The remaining sections of the chapter concentrate on the technicalities of law in a broader sense, using Roman law as a case-study: how, exactly, do legal rules and concepts ‘come to life' within institutionalized contexts and traditions? Rather than focusing on rules, concepts, and categories in relation to doctrine, we need to think about an ethnology of legal rhetoric: about the roles that rules and categories play within cultures of reasoned argument. The substance of the analysis is provided by Quintilian’s first-century Institutes of Rhetoric.