Definition
A Latin phrase meaning "to inquire." In its legal sense, ad inquirendum refers to a judicial writ commanding that an inquiry or investigation be made into a matter relating to a cause pending before a court. The writ directed an officer — typically a sheriff or other court officer — to conduct an examination or inquest and return the findings to the court.
The full form most often encountered in historical records is breve ad inquirendum, meaning "writ to inquire," though the phrase ad inquirendum alone functions as a shorthand reference to any such writ of inquiry.
Why It Matters in Research
Ad inquirendum is an archaic procedural term and will appear almost exclusively in pre-nineteenth-century common law sources, English ecclesiastical and chancery records, and colonial American legal documents. Researchers encountering it in historical pleadings or court records should understand it as the authorization mechanism by which a court directed a fact-finding inquest into a specific question — damages, title, value, or other factual matters — without deciding the underlying dispute itself.
The term is closely related to the broader family of ad writs (ad quod damnum, ad melius inquirendum, etc.) that characterized the old writ system. A researcher working through early English or American common law records who sees ad inquirendum should look for the corresponding inquest return, which is where the substantive findings will appear. The writ itself establishes authority; the return carries the content.
Because modern procedural systems replaced the writ system, you will not encounter this term in contemporary case law or statutes. Its relevance is almost entirely historical and doctrinal. When tracing chains of title, early land grants, or ecclesiastical disputes in Law Mind corpus materials, the writ's existence in the record signals a court-ordered factual investigation rather than a final adjudication.
The attribution to Cowell — John Cowell's Interpreter (1607) — in all three source dictionaries is significant. Black's and Burrill's both trace the definition directly to that source, which means the legal dictionaries are themselves working from a seventeenth-century authority. Researchers should treat the definition as a relay from Cowell rather than an independently synthesized modern description.
Historical Dictionary Support
All three historical sources — Black's Law Dictionary (1st and 2nd editions) and Burrill's Law Dictionary — are in complete agreement on substance and virtually identical in wording. Each defines ad inquirendum as a judicial writ commanding inquiry into a matter in a pending cause, and each traces the authority to Cowell's Interpreter. The near-verbatim agreement signals that subsequent dictionaries copied from Black's rather than returning independently to primary sources.
Burrill adds the expanded Latin form breve ad inquirendum explicitly, which is a useful clarification that the other entries imply but do not foreground. This makes Burrill's entry marginally more useful for a researcher trying to identify variant forms of the term in original documents.
What none of the historical entries address is the procedural mechanics: who executed such a writ, what form the return took, or how the inquiry related to the ultimate judgment. For that level of detail, researchers should consult Blackstone's Commentaries or Fitzherbert's Natura Brevium, which treat the writ system with greater procedural specificity than any of the dictionary sources.
Jurisdictional Note
Ad inquirendum belongs to the English common law writ system and was carried into early American practice in the colonial and early republic periods. As American courts adopted reformed pleading systems through the nineteenth century — culminating in code pleading and later the Federal Rules — writs of this type were abolished or subsumed into modern procedural mechanisms. The term has no operative force in any current U.S. jurisdiction.