The first extended study of Bruno Latour's legal theory, this book presents a critical reconstruction of the whole of Latour's oeuvre to date, from Laboratory Life to An Inquiry into the Modes of Existence. The book advances a new theory of legal normativity and the force of law, rethinking Latour's work on technology, the image, and referential scientific inscriptions, and placing them within the ambit of legality. It also develops the contrast between the modern legal institution and the value of law as a mode of existence. Throughout, Latour's thought is put into dialogue with important progenitors and adversaries as well as historical and contemporary strands of legal and political philosophy. This interdisciplinary study will be of interest to those researching Law, Philosophy, and Sociology.