Definition
Jus singulare (Latin: "singular law" or "individual law") is a term from Roman and civil law denoting a rule of law that departs from the general or ordinary rule — the jus commune — and was established for a special reason applicable to a particular person, class of persons, or category of cases. It is, in essence, an exception built into the legal system itself: not a mere judicial exception in a given dispute, but a deliberately crafted departure from the normal legal order, recognized as valid precisely because the legislature or legal authority saw sufficient cause to treat some persons or situations differently.
Where the benefit of a jus singulare attaches to a class of persons rather than to the general public, it shades into the concept of privilege. Bouvier draws this distinction carefully: when the departure from ordinary law favors identifiable classes, the jus singulare functions as an objective privilege; when a specific right is conferred by leges speciales (special laws) upon a definite individual, it becomes subjective privilege in the technical civil-law sense.
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Common Language
This is pure Latin legal jargon with no counterpart in ordinary English usage. The COMMON LANGUAGE section is omitted.
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Common Confusion
Jus singulare is most easily confused with jus commune, its conceptual opposite. Jus commune is the general rule — the baseline of the legal system — while jus singulare is the deliberate deviation from that baseline. The two terms are defined in relation to each other and must be understood as a pair.
Researchers should also distinguish jus singulare from mere judicial exceptions or equitable relief: a court's discretionary departure from a rule in a particular case is not a jus singulare. The term describes a structural feature of the legal order — an exception formalized by legal authority — not an ad hoc result.
Finally, jus singulare should not be conflated with privilege in the modern common-law sense (evidentiary privileges, legislative immunity). Though Bouvier connects the concepts, the civil-law usage is broader and refers to any law of special application, not only to immunities or protections.
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Why It Matters in Research
Researchers working in civil-law jurisdictions, comparative law, or the history of Roman law will encounter jus singulare as a technical term of art with a precise structural meaning. Several navigational points are worth noting.
First, the term appears in scholarship and primary sources dealing with Roman law, canon law, and the ius commune tradition of Continental Europe. It surfaces in discussions of legal exceptionalism — how pre-modern legal systems accommodated the tension between general rules and the need to treat certain persons or situations differently. Understanding jus singulare as a formal category (not a casual exception) is essential to reading those sources correctly.
Second, Bouvier's entry is the most analytically developed of the historical dictionaries: it distinguishes objective privilege (benefit to a class) from subjective privilege (benefit to an individual by leges speciales). This distinction has real utility for researchers tracing the conceptual genealogy of modern privilege doctrines, especially in civilian legal systems. The Black's entries, by contrast, give only the basic definitional statement and refer to Mackeldey's Roman Law — a standard 19th-century treatise — without elaborating the internal distinctions Bouvier draws.
Third, researchers approaching this term from a common-law background should resist mapping it directly onto common-law categories. The civil-law concept of a formally recognized anomalous rule sitting alongside — but not overriding — the general law has no clean common-law analogue. Treating it as equivalent to a statutory exception or common-law privilege will introduce anachronism.
Fourth, the term may appear in glossaries and marginal annotations of early modern legal manuscripts alongside related Latin terms. Knowing that jus singulare always implies a counterpart jus commune will help researchers orient themselves when one term appears without the other.
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Historical Dictionary Support
The four historical dictionaries show substantial agreement on the core definition: jus singulare is a peculiar or anomalous rule, established for special reason, departing from the jus commune. Black's (both editions) and Burrill's are nearly identical in wording, all tracing directly to Mackeldey's Civil Law — Burrill citing it as 1 Mackeld. Civ. Law, 181, § 188; Black's citing § 196 (a variant section reference likely reflecting different editions of Mackeldey's treatise). Researchers should be aware that multiple editions of Mackeldey circulated in the 19th century with differing section numbering.
Bouvier's entry is the most substantively developed, adding the objective/subjective privilege distinction and introducing the concept of leges speciales. This makes Bouvier the most useful starting point for researchers interested in the doctrinal content of the term rather than merely its definition.
What the historical dictionaries collectively omit is any discussion of how jus singulare functioned in practice in Roman or canon law — what kinds of departures from the jus commune were actually recognized, and how courts or authorities justified them. For that level of detail, researchers must go to primary civil-law scholarship; the dictionary sources are definitional only.
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Jurisdictional Note
Jus singulare is a term of civil law and Roman law origin. It has no recognized technical meaning in Anglo-American common law. It appears primarily in comparative law scholarship, historical legal analysis, and sources dealing with civil-law jurisdictions (Continental Europe, Louisiana, Quebec, and systems derived from Roman law). Common-law researchers encountering the term in historical sources should treat it as a civil-law concept requiring civil-law interpretive tools.
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