Definition
ARG is an abbreviation of arguendo, a Latin phrase meaning "for the sake of argument." When ARG appears in legal reports and opinions, it signals that what follows is assumed or conceded for purposes of argument only — not established as fact or law. The concession or proposition introduced by ARG (or arguendo) carries no binding or precedential weight; it is a rhetorical and analytical device allowing a court or advocate to reason through a hypothetical without committing to it.
In older civil law contexts, ARG prefixed to a citation from Roman or civil law sources carries a more specific technical meaning: the cited text is offered not as direct authority but as consequential or analogical proof — supporting an inference rather than establishing a rule outright.
Common Language
Modern common usage (Wiktionary): "An argument; a value passed as a parameter" — used primarily in computing to refer to an input value in a function or command.
Historical common usage (Webster's 1913): Webster's 1913 does not list ARG as a standalone entry; it appears only as a contraction.
The computing sense of "arg" (short for argument, meaning a parameter passed to a function) and the legal abbreviation ARG are unrelated despite sharing the same root. A researcher encountering ARG in a legal text should not import any computing or informal English meaning. The legal ARG signals a conditional assumption, not a substantive assertion.
Common Confusion
ARG is sometimes read as a substantive citation signal rather than a conditional one. When a court writes ARG followed by a rule or principle, that rule is being assumed for analytical purposes — it is not the court's holding. Conflating arguendo assumptions with actual holdings is a significant research error, particularly when working backward from secondary sources that quote arguendo passages without flagging their conditional character.
Why It Matters in Research
The primary research trap with ARG is misreading it as a positive citation or affirmation. In older reports especially, ARG appears embedded in dense citation strings, and a researcher skimming for authority may lift an arguendo proposition as if it were settled law. Always trace ARG back to the underlying arguendo passage to verify whether the court ultimately accepted, rejected, or left open the proposition it assumed.
In civil law research, Burrill's gloss adds a layer of complexity: ARG prefixed to a civil law source signals analogical reasoning, not direct authority. This distinction matters when working with early American cases that drew on Roman and civil law traditions — the weight of the cited text is deliberately qualified.
The abbreviation is rare in modern practice. Contemporary opinions spell out "arguendo" or use the phrase "assuming without deciding." Researchers in pre-twentieth-century reports will encounter ARG far more frequently than those working in modern slip opinions or reporters.
Historical Dictionary Support
All three source dictionaries agree that ARG is an abbreviation of arguendo and nothing more — Black's (both editions) treats it as a simple cross-reference entry. Burrill's is the only source that elaborates, offering the civil law gloss about consequential versus direct proof. This distinction is absent from both Black's editions, which may reflect the diminishing relevance of Roman law citations in American practice by the time of those editions. Researchers working in civilian jurisdictions or early republic materials should weight Burrill's note accordingly. No historical dictionary sources define ARG as anything other than this abbreviation.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Arguendo; Citation Signals and Abbreviations in Legal Reports.