Definition
Latin. "I call," "I summon," or "I vouch." A term from Roman civil law and early English legal practice appearing in two distinct procedural formulas:
(1) As a summons formula: The word anchors the phrase in jus voco te — "I summon you to court" or "I summon you before the praetor." This was the verbal formula by which a Roman legal action was anciently commenced, spoken by the plaintiff directly to the defendant as a formal call to appear before the magistrate.
(2) As a vouching formula: In old English law, voco talem — "I call" or "I vouch such a one" — was the formula used in vouching to warranty, a procedural device by which a defendant in a real property action called upon a third party (the warrantor) to defend the title and, if the defense failed, to provide equivalent land in exchange.
Common Confusion
The two procedural uses of voco are historically distinct and should not be conflated. The summons use (in jus voco te) belongs to Roman civil procedure and concerns the initiation of an action. The vouching use (voco talem) belongs to old English real property practice and concerns warranty of title. Both appear under the same headword in historical dictionaries, which can mislead a researcher into treating them as a single concept. They operate in entirely different procedural contexts.
Why It Matters in Research
Voco is a term encountered almost exclusively in historical legal sources — Roman law treatises, Bracton, Fleta, and their descendants in early English common law. Researchers will not find it in modern procedural codes or contemporary case law.
The primary research trap is context collapse: when a source uses voco without the surrounding formula, it may not be immediately clear whether a summons or a warranty voucher is being described. Burrill's entry is the most complete of the historical dictionaries on this point, explicitly distinguishing the two formulas and providing citations to both Bracton (fol. 382b) and Fleta (lib. 6, c. 23, § 20) for the vouching usage. Black's (both editions) covers only the summons formula with any detail.
For researchers working on Roman civil procedure, the in jus voco te formula represents the pre-classical commencement of an actio — the moment before the proceedings were formalized before the praetor. Adam's Roman Antiquities (cited across all three source dictionaries) is the primary reference. The formula fell away as Roman procedure developed the more structured legis actiones and later the formulary system.
For researchers working in English real property history, voco talem connects directly to the doctrine of vouching to warranty — a mechanism central to medieval land tenure and the basis for later warranty covenants in deeds. Bracton and Fleta are the authoritative primary sources for this usage, and both are cited by Burrill.
Neither usage has a live procedural counterpart in modern American or English law. The term is essentially archival.
Historical Dictionary Support
All three source dictionaries agree on the core translation ("I call; I summon; I vouch") and on the summons formula (in jus voco te), with identical reference to Adams, Roman Antiquities, at page 242. This convergence is likely a case of later dictionaries drawing directly from earlier sources rather than independent verification.
Burrill's is meaningfully richer. It alone provides the vouching formula (voco talem) with supporting citations to Bracton and Fleta — primary sources that ground the English law usage in specific medieval authority. Black's (both editions) omits this entirely, which is a notable gap for any researcher whose interest lies in English property law rather than Roman procedure.
No historical dictionary addresses the decline of either formula or contextualizes voco within the broader shift from formulaic oral pleading to written process. Researchers needing that developmental arc must go beyond the dictionary shelf to primary sources and legal history scholarship.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Vouching to Warranty; Roman Civil Procedure; Commencement of Action (Historical).