Definition
A Latin term from Roman and civil law meaning, literally, "a throwing together of a cause." In practice, it denotes a brief, summary statement of a case presented by an advocate to the judge at the opening of a trial. The conjectio cause was not an argument on the merits but a preliminary synopsis — a condensed narrative of the facts and issues — delivered so that the judge could orient himself to the dispute before hearing full pleadings or oral argument.
The function was procedural and orienting: to give the tribunal a working frame before testimony or advocacy began in earnest.
Why It Matters in Research
This term appears almost exclusively in historical legal dictionaries and treatises on Roman and civil law procedure. Researchers are unlikely to encounter it in common law sources, Anglo-American case reporters, or modern statutory codes. Its relevance is primarily confined to:
1. Historical scholarship on Roman law procedure and its transmission into continental civil law systems.
2. Comparative law research tracing how the civil law tradition structured trial openings versus the common law tradition.
3. Ecclesiastical and admiralty law research, where Roman civil law procedure had significant influence on English practice.
The term is rarely indexed in modern legal databases. Researchers working in primary sources on pre-modern civil law or canon law procedure should watch for variant spellings and Latin abbreviations. The phrase may appear compressed or paraphrased in translated treatises without the Latin term being used at all.
Do not confuse this term with "cause" in the modern procedural sense, or with "probable cause" as a constitutional standard. The word "cause" here is the Latin causa, meaning a legal matter or case — not causation in the tort or criminal law sense.
Historical Dictionary Support
All four historical sources — Black's, Bouvier's, Rapalje & Lawrence, and Burrill's — are in close agreement on both meaning and authority, each citing Calvinus's Lexicon Juridicum (a standard reference for civil law terminology) as the underlying source. This convergence reflects the dictionaries' shared reliance on the same Roman law lexicographical tradition rather than independent verification.
Burrill's entry is the most expansive, explicitly situating the term within Roman law and providing the translation "throwing together of a cause" — a rendering that captures the procedural character of the act: assembling the disparate elements of a dispute into a brief, workable summary for the judge's benefit.
Rapalje & Lawrence adds the useful procedural detail that the conjectio cause was "handed to the judge" by respective advocates — suggesting it may have sometimes taken written form, not merely oral recitation. This detail is absent from Black's and Bouvier's, which describe only an oral synopsis. Researchers relying solely on Black's or Bouvier's may miss this written-document dimension.
None of the historical dictionaries provide depth on how the practice varied across different civil law jurisdictions or periods, nor do they trace the term's fate as Roman procedure evolved. The entries are definitional snapshots, not historical analyses.
Jurisdictional Note
The conjectio cause is a Roman law and civil law concept. It has no direct counterpart in the common law tradition, though the functional equivalent — an opening statement by counsel — is standard in both systems. Researchers working in Scots law, Louisiana law, or other mixed civil-common law jurisdictions may find the concept cited in older procedural authorities, but it carries no operative legal weight in modern courts.