Definition
Arguendo (Latin: "in arguing") is a term used to signal that a statement, assumption, or fact is being accepted or asserted for the purpose of argument only, without any commitment to its truth or legal significance. A court or counsel proceeding arguendo acknowledges a premise—however disputed or doubtful—in order to test what follows from it, or to resolve a narrower issue without deciding the broader one.
The term operates in two related but distinct contexts:
1. Judicial statements made arguendo. When a judge makes an observation or raises a point during oral argument or in written opinion not as a holding but as a hypothetical or illustrative aside, that statement is made arguendo. It carries no precedential weight. It is the judge thinking aloud, not deciding.
2. Assumptions made arguendo. When a party or court assumes a fact or legal proposition to be true for purposes of the immediate analytical step—without conceding it and without the court finding it—the assumption is made arguendo. Courts often use this technique to dispose of a case on a threshold or narrower ground: "Assuming arguendo that the plaintiff could establish standing, the claim still fails on the merits."
Common Language
Wiktionary: "For the sake of argument; assuming without deciding; identifying the premises of a hypothetical argument while making it clear that no finding is being made on whether the premises are true."
No Webster's 1913 entry exists for arguendo. The term is Latin legal vocabulary that passed into English legal usage without meaningful common adoption.
Editorial note: Arguendo does appear in general educated usage—"for the sake of argument" captures the intuition—but the legal meaning carries a precise procedural consequence that ordinary use obscures. In law, a statement or assumption made arguendo is formally quarantined from the record of findings. It cannot be used as a concession, extracted as precedent, or treated as a judicial determination. The casual phrase "for the sake of argument" implies no such formal consequence.
Common Confusion
Arguendo is frequently confused with obiter dictum. Both describe statements that fall outside binding legal holdings, but they are not the same. Obiter dictum is a judicial remark in an opinion—offered as context, explanation, or illustration—that was not necessary to the decision. Arguendo describes statements or assumptions made during the course of argument (by counsel or the court), specifically flagging that no determination is being made. A statement can be both: a judge may make an arguendo assumption in writing that also qualifies as dictum. But not all dictum is arguendo, and not all arguendo statements end up in opinions as dictum. Researchers reading older reports should be alert to this overlap and resist treating arguendo observations as authoritative even when they appear in published decisions.
Why It Matters in Research
The practical research trap with arguendo is treating judicial arguendo statements as holdings or as implicit concessions. When a court writes "assuming arguendo that X is true, we nonetheless hold Y," the court has decided Y—it has not decided X. Citing such a passage as authority for X is a fundamental misreading of the opinion.
In older reports, the abbreviation arg. appears in place of arguendo and can be missed entirely by researchers skimming for holdings. Black's both editions flag this abbreviation; researchers working in nineteenth-century case law should recognize it on sight.
For corpus researchers in Law Mind, arguendo appears with high frequency in appellate opinions and oral argument transcripts. Its appearance is almost always a structural signal: the court is bracketing a disputed or difficult issue to reach a cleaner ground of decision. Identifying arguendo passages in a body of case law is a useful way to map which legal questions a court found difficult, unsettled, or strategically avoidable—even if the court never formally resolved them.
The term also surfaces in legal briefs, where counsel may concede a point arguendo to sharpen the presentation of a winning alternative argument. These brief-level arguendo concessions are not binding admissions and should not be read as such in later proceedings.
Historical Dictionary Support
Both editions of Black's are substantively identical on this term, defining arguendo as "in arguing; in the course of the argument" and focusing on the judicial statement context—observations made by a judge that are not directly bearing on the case at bar. The second edition's entry contains a minor typographical variant ("argucndo" for "arguendo") consistent with the scanning artifacts common in that edition and not a meaningful textual difference.
What both editions underemphasize is the assumption use of arguendo, which has become equally if not more prominent in modern legal writing. The classic Black's framing centers on judges making incidental remarks during argument or in reports; contemporary usage extends equally to the technique of conditional assumption used to sidestep difficult issues. Neither edition addresses the brief-writing context at all.
The Wiktionary definition is actually more complete than Black's for modern purposes, capturing both the "assuming without deciding" sense and the function of separating assumed facts from disputed facts.