Definition
A Latin maxim of jurisprudence meaning, in full: "If the written law be silent, that which is drawn from manners and custom ought to be observed; and, if that is in any manner defective, then that which is nearest and analogous to it; and, if that does not appear, then the law which Rome uses ought to be observed." The maxim establishes a formal hierarchy of legal authority to be applied when statutory law fails to provide an answer. In sequence: (1) written law governs first; (2) where written law is silent, custom and established practice control; (3) where custom is deficient, the nearest analogous rule applies; and (4) where analogy also fails, Roman civil law serves as the residual authority. The maxim originates from the Digest of Justinian and was carried into English legal discourse primarily through Coke's reports.
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Common Confusion
The maxim is sometimes misread as a statement about the supremacy of custom over statute. It is the opposite: written law takes priority, and custom is the fallback when written law is silent. The hierarchy runs downward from lex scripta — the maxim does not elevate custom; it positions custom as the first resort after statutory silence. Researchers should also distinguish this maxim from lex non scripta, which refers to unwritten or customary law as a category, without carrying the hierarchical framework this maxim encodes.
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Core Elements
The maxim encodes a four-step gap-filling hierarchy:
1. LEX SCRIPTA (Written Law): The first and controlling source. Statutes, codes, and enacted law govern when they speak to the question.
2. MORES ET CONSUETUDO (Manners and Custom): Where written law is silent, established custom — the accumulated practices accepted as binding within a community — fills the gap.
3. PROXIMUM ET CONSEQUENS (Nearest Analogous Rule): Where custom is itself deficient or inapplicable, the rule most nearly resembling the situation by analogy is applied.
4. JUS ROMANUM (Roman Law): The final residual authority. Where no custom and no analogy resolves the matter, the law of Rome as a common jurisprudential baseline supplies the answer.
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Why It Matters in Research
This maxim is primarily a tool for understanding the intellectual architecture of early common law and civil law reasoning, not a rule applied by modern courts as such. Researchers working in pre-modern English legal sources — particularly in equity, ecclesiastical courts, and admiralty — will encounter the maxim or its logic in contexts where Roman civil law was treated as persuasive or gap-filling authority. The maxim's invocation of Roman law as the terminal fallback reflects the civilian tradition's influence on English courts operating outside the common law proper.
The critical research trap is anachronism: modern common law systems do not formally adopt Roman law as a residual source, so the maxim's fourth step has no direct modern application in most Anglo-American jurisdictions. Its value in contemporary research is interpretive and historical — it illuminates how courts and jurists in the civilian tradition reasoned about gaps in positive law, and it surfaces in scholarship on legal pluralism, comparative law, and the historical relationship between Roman and English legal systems.
Researchers using Black's Law Dictionary (2nd Ed.) should note that the entry for this maxim is incomplete as preserved — the text cuts off mid-sentence. The full maxim, sourced from 7 Coke 19 and ultimately from Justinian's Digest (1.3.32), is necessary to understand the complete hierarchy. Reliance on the truncated Black's entry alone will produce an incomplete picture of the maxim's scope.
The maxim also has relevance in Scottish and mixed-jurisdiction legal history, where Roman law retained formal authority as a gap-filler longer than in English common law.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the Latin text and the citation to 7 Coke 19, but the entry is truncated, cutting off before the enumeration of the third and fourth steps in the hierarchy. This is a notable limitation: researchers relying solely on Black's will see only the first two tiers (written law, then custom) and miss the analogical reasoning step and the Roman law fallback entirely.
The maxim's origin in Justinian's Digest (attributed to Julian) predates its English reception by more than a millennium. Coke's invocation of it in the seventeenth century reflects the period's active dialogue between common law and civilian learning. Historical legal dictionaries generally treat the maxim as a civilian principle rather than a common law rule, which is accurate — it describes a methodology more native to civil law systems than to the English common law tradition of precedent and parliamentary statute.
No significant divergence exists among historical sources on the maxim's meaning; the variation lies in how fully each source reproduces the Latin text and whether the Roman law fallback is acknowledged.
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Jurisdictional Note
The maxim retains conceptual relevance in civil law and mixed legal systems — Louisiana, Quebec, Scotland, and South Africa among them — where Roman law has historically functioned as a formal or persuasive gap-filler. In pure common law jurisdictions, the hierarchy the maxim describes does not operate as stated; custom and analogy remain relevant tools, but Roman law as a terminal fallback does not.
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