This book is about the use of legal scholarship by judges. It discusses the possibility that legal scholarship may function as a genuine source of law in modern municipal legal systems. The book advances a number of claims, some conceptual, some empirical, some normative. The major conceptual claims are found in Chapters 2 and 3, where a general account of the notion of a source of law is provided. Roughly, sources of law are documents or practices (e.g. statutes, judicial decisions, official customs) from which norms can be derived that function as sources of content-independent reasons...