Definition
Written law is law that derives its binding force from an authoritative text — most commonly, from express enactment by a legislature or other recognized lawmaking body. The term operates at two levels of generality:
1. In common law systems: Written law means statute law — acts of a legislature, as distinguished from unwritten or common law, which derives its authority from custom, judicial decision, and usage rather than from formal enactment.
2. In Roman and civil law systems: Written law (jus scriptum, lex scripta) was one of the two fundamental divisions of Roman law and encompassed a broader category than statutes alone. It included the leges (laws passed by popular assemblies), plebiscita (enactments of the plebeian assembly), senatus-consulta (decrees of the Senate), principum placita (imperial constitutions), magistratuum edicta (edicts of magistrates), and responsa prudentum (authoritative opinions of recognized jurists).
The breadth of the Roman meaning reflects a different organizing principle: the distinction was between law that had been formally committed to writing and authenticated, versus law that existed in custom and practice. In the common law tradition, the distinction narrowed to roughly legislative versus judicial origin.
Common Language
Modern common usage (Wiktionary): "Written law" in ordinary English generally means any law that has been set down in text — a statute, code, or formal document — as opposed to unwritten norms or traditions.
Historical common usage (Webster's 1913): Webster's does not treat "written law" as a discrete common entry; it would be understood as the plain combination of "written" and "law" — law expressed in writing.
The gap between common and legal meaning is real but subtle. An ordinary reader would assume any codified or documented rule qualifies as written law. The legal tradition is more precise: in common law usage, written law typically signals statutory law specifically — enacted text — as opposed to the body of judge-made common law, much of which also exists in written form as reported decisions. The word "written" in the legal term denotes formal legislative promulgation, not merely the existence of a text.
Common Confusion
Written law is frequently contrasted with, and therefore confused with, unwritten law and common law. The confusion is compounded because common law decisions are, in fact, written — recorded in reports and opinions. The distinction is not about whether words appear on paper but about the source of authority. Written law derives its force from explicit enactment; unwritten or common law derives its force from custom, long usage, and judicial recognition. A researcher encountering "written law" in a historical source should resist the modern reflex to read it as meaning any documented legal rule.
Why It Matters in Research
The term's meaning shifts depending on which legal tradition the source is working in. In sources drawing on Roman or civil law — treatises, equity scholarship, conflicts of law materials, and early American works influenced by continental learning — "written law" carries the broader Roman classification, covering everything from statutes to imperial edicts to jurists' opinions. In common law sources, including most English and American case law, the term narrows to statutory law. Reading across these traditions without accounting for the distinction produces distortion.
Blackstone's treatment is the fulcrum for common law usage. His Commentaries (1 Bl. Comm. 62, 85) anchor the definition that Bouvier, Black's, and the rest of the common law dictionaries repeat almost verbatim. Any historical source citing Blackstone on this point is working within the common law narrowing.
The Roman law classification matters for researchers working in civil procedure history, comparative law, or early American constitutional theory, where the jus scriptum / jus non scriptum divide informed arguments about the nature of constitutional versus common law authority. The Institutes of Justinian (Inst. 1.2.3) are the primary authority for the Roman enumeration.
For corpus research, note that "written law" rarely appears as a term of art in modern American statutory or case law — it has been largely displaced by more specific terms like "statute," "code," or "positive law." Its appearance in a source is itself a signal: the author is usually working in a comparative, historical, or foundational register.
Historical Dictionary Support
The historical dictionaries are in close agreement on both meanings. Burrill's Law Dictionary is the most complete, supplying the Latin (jus scriptum, lex scripta) and Greek (νόμος ἔγγράφος) equivalents alongside both the Roman and common law definitions, and directing the reader to the entry for Lex scripta. Black's (both editions) and Bouvier's reproduce the same dual definition, with Black's 1st edition also including an unrelated English procedural note about writs of trial that appears to be a source artifact and does not bear on the meaning of written law.
All sources cite the same two authorities: Justinian's Institutes for the Roman classification and Blackstone's Commentaries for the statute law definition. No significant divergence exists among the dictionaries on substance. The notable gap in the historical dictionaries is the absence of any discussion of constitutional law as a form of written law — a question that became significant in American jurisprudence and that none of these dictionary entries address. Researchers looking for that dimension will need to go beyond dictionary sources.
Jurisdictional Note
The common law meaning (written law as statute law) applies throughout English and American legal tradition. Civil law jurisdictions retain the broader Roman classification. In mixed jurisdictions such as Louisiana, Quebec, and Scotland, the term may carry civil law resonance even in contemporary sources.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Common Law; Statute; Jus Scriptum; Positive Law