Definition
A Latin term from the civil law meaning conjunction or connection — specifically, the joining of words within a sentence or legal text. Conjunctio appears in juristic writing primarily as a term of grammatical and logical interpretation: when words in a legal instrument or statute are joined by conjunctio (conjunction), the interpreter must determine whether the linking creates a cumulative obligation (requiring all conditions to be satisfied) or merely a connective structure. The term carries no independent substantive meaning outside of interpretive and textual analysis.
The maxim attached to the term in some sources — Conjunctio mariti et feminae est de jure naturae ("The union of husband and wife is of the law of nature") — uses conjunctio in a broader sense, meaning union or joining of persons, and reflects the natural-law foundations of Roman family law rather than any grammatical principle.
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Common Confusion
The term encompasses two distinct uses that sources sometimes present without distinguishing them. The first is the narrow grammatical-interpretive sense: conjunctio as the connection of words in a legal text, relevant to construing instruments. The second is the broader personal or relational sense: conjunctio as the joining of persons, as in the marriage maxim. A researcher encountering conjunctio in a civil law treatise on interpretation is in different territory than one encountering it in a discussion of natural law or family relations. The historical dictionaries do not clearly separate these uses.
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Why It Matters in Research
Conjunctio is a term of Roman juristic grammar, and researchers are most likely to encounter it in two contexts: (1) interpretive passages in civil law texts and their common-law successors, where the question is whether a conjunctive construction in a statute or instrument requires strict cumulative satisfaction of conditions; and (2) natural-law discussions of marriage and domestic relations, via the maxim Conjunctio mariti et feminae est de jure naturae.
For the interpretive context, the Digest reference (Dig. 50, 16, 29 and 142) points to the title De verborum significatione — the Roman law title on the meaning of words — which is the juristic home of this term. Researchers working in civil law jurisdictions, mixed legal systems (Louisiana, Quebec, South Africa), or in historical common-law sources that drew on civilian learning should look to that title for the full context. The question of conjunctive versus disjunctive construction in instruments and statutes is a live issue in modern legal interpretation and may be traced through this lineage.
For the marriage maxim, the phrase appears in natural law and ecclesiastical legal writing and is not a rule of positive law but rather a juristic commonplace asserting the natural foundation of marriage. It should not be read as an operative legal standard; its role in sources is rhetorical and philosophical rather than doctrinal.
Researchers using early American or English legal dictionaries should be aware that conjunctio is typically listed without distinguishing these two registers, which can create confusion when tracing an argument through sources.
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Historical Dictionary Support
All three source dictionaries agree on the core definition: conjunctio means conjunction or connection of words in a sentence, citing Dig. 50, 16, 29, 142. Black's (both editions) and Burrill are essentially identical on this point, with Burrill adding the Latin root conjungere (to join together) for clarity.
Black's (both editions) appends the marriage maxim — Conjunctio mariti et feminae est de jure naturae — without explanation of how it relates to the grammatical definition. Burrill omits the maxim entirely. This divergence is instructive: the maxim is almost certainly included by Black's as a secondary entry or associated phrase rather than as an elaboration of the grammatical sense, but the layout implies a connection that is not fully developed. Neither dictionary explains the Digest context in any depth, and none addresses the interpretive significance of conjunctive versus disjunctive construction that gives the term its practical interest.
What the historical dictionaries collectively miss: any treatment of conjunctio as an interpretive tool, any engagement with the distinction between copulative and disjunctive conjunctions in legal drafting, and any discussion of how the term travelled from Roman jurisprudence into civilian and common-law interpretive practice.
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Jurisdictional Note
The term is primarily relevant in civil law jurisdictions and in historical common-law sources with significant civilian influence. In Louisiana and other mixed systems, the interpretive tradition drawing on Roman grammar and the Digest remains closer to the surface. In purely common-law jurisdictions, the underlying concept (conjunctive versus disjunctive construction) is fully operative but the Latin terminology is rarely used.
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