Definition
Latin: "written law." Jus scriptum denotes the body of law that has been formally reduced to writing, as distinguished from unwritten law that exists through custom, usage, and tradition. The term carries two related but distinct applications depending on the legal system under discussion.
In Roman law, jus scriptum encompassed all law actually committed to writing, regardless of its origin. This included law derived from legislative enactment and law derived from custom — so long as the custom had been formally written down. The key distinction was not the source of the rule but whether the rule had been set in writing. Its counterpart was jus non scriptum, the unwritten law, which consisted of those customs and usages recognized as binding but never formally recorded.
In English law, the term was imported with a narrower and more pointed meaning: jus scriptum became essentially synonymous with statute law — the written, enacted law of the legislature — in contrast to the common law. English legal writers, most prominently Blackstone, used the pairing lex scripta (jus scriptum) and lex non scripta (jus non scriptum) to organize the entire body of English law into enacted rules on one side and common law, custom, and usage on the other.
Common Confusion
The Roman and English uses of jus scriptum are not identical, and treating them as equivalent creates analytical error. In Roman law, jus scriptum was broader: a custom reduced to writing became jus scriptum even if no legislature enacted it. In English law, jus scriptum effectively collapsed into statutory law — if Parliament wrote it, it was jus scriptum; if judges and custom developed it, it was jus non scriptum. A researcher encountering the term in a Roman law treatise and again in an English law commentary is not reading about the same concept, even though the Latin phrase is identical.
Why It Matters in Research
The principal research trap with jus scriptum is the contextual shift described above. Treatises and commentaries from the civil law tradition and those from the English common law tradition use the same phrase to mean subtly different things, and historical dictionaries do not always flag this divergence clearly.
In Roman law sources — Justinian's Institutes being the foundational text — jus scriptum is a classification about form, not origin. Custom that was written down crossed into jus scriptum territory. This matters when reading civilian-influenced jurisdictions, particularly Louisiana, Quebec, or South African sources, where the Roman law meaning may govern analysis.
In English common law sources, particularly Blackstone's Commentaries, jus scriptum is a rough synonym for Acts of Parliament. When nineteenth-century American legal writers borrowed this framework, they carried the English usage with them, so American treatises on statutory construction that reference jus scriptum are working within the English, not the Roman, frame.
Researchers working in the Law Mind corpus should also be alert to the related term jus non scriptum, which appears more frequently than jus scriptum in discussions of customary law and common law foundations. The two terms are defined relationally and should always be read together. Entries discussing the sources of law in Roman and civil law systems will frequently use jus scriptum as the anchor point for organizing the entire taxonomy of legal sources.
Finally, Rapalje & Lawrence's entry for this term is unhelpful — their dictionary redirects to a general entry on jus rather than defining jus scriptum directly, and the maxim quoted (jus superveniens auctori accrescit successori) is unrelated. Bouvier's entry provided here covers jus civitatis, not jus scriptum, indicating a sourcing artifact. Researchers should weight Black's and Burrill's entries as the reliable references in the historical dictionary shelf for this term.
Historical Dictionary Support
Black's Law Dictionary and Burrill's Law Dictionary are in close agreement, and their entries are clearly drawing from the same Roman law source material — Mackeldey's Civil Law (cited by both as the authority on the Roman definition). Both dictionaries correctly identify the dual application of the term across Roman and English law, and both correctly cite Justinian's Institutes (Book 1, Title 2, Section 3) as the foundational Roman law source. Burrill's entry is marginally more precise, specifying the Greek equivalent (νομος έγγραφος) and giving a more exact Mackeldey citation, but the substantive content is the same.
Neither dictionary fully develops the analytical difference between the Roman and English meanings, treating them more as parallel translations than as potentially divergent concepts. Modern research in comparative or civil law contexts should supplement these historical entries with primary Roman law sources and civilian commentary.
Jurisdictional Note
The English usage of jus scriptum as equivalent to statute law is the dominant frame in American legal writing. Civil law jurisdictions — particularly Louisiana — may deploy the Roman meaning, where written custom also qualifies as jus scriptum. Researchers working across both traditions should establish which frame applies before relying on secondary sources.