Definition
A pure plea is a pleading in equity that relies entirely on matter outside the bill — that is, on facts not mentioned or referred to in the plaintiff's bill of complaint. Rather than denying or explaining the allegations already on the face of the bill, a pure plea raises entirely new, extraneous matter that, if true, bars the plaintiff's suit or defeats the equity claimed. The classic example is a plea of release on a settled account: the plaintiff's bill may establish a facially valid claim, but the defendant answers not by contesting those facts, but by asserting that the parties have already settled and released the obligation — a fact wholly external to the bill itself.
A pure plea stands in contrast to a negative plea (sometimes called an impure plea), which relies on matter within or connected to the bill, typically by denying or qualifying allegations already present in the plaintiff's pleading.
Common Confusion
PURE PLEA vs. NEGATIVE PLEA (IMPURE PLEA): The distinction turns entirely on the source of the pleading's operative matter. A pure plea introduces facts dehors (outside) the bill. A negative plea draws its substance from matter already in the bill, contradicting or qualifying what the plaintiff has already alleged. Confusing the two matters in equity practice because the procedural posture and the defendant's burden differ. A defendant putting forward a pure plea is effectively saying: "Even if everything in your bill is true, this separate fact defeats your claim." A negative plea instead contests the bill on its own terms.
PURE PLEA vs. DEMURRER: A demurrer admits the bill's facts for argument's sake and challenges legal sufficiency. A pure plea admits nothing and introduces new extrinsic matter. Researchers working in pre-reform equity records will encounter both and must distinguish them to understand what each party was actually arguing.
Why It Matters in Research
Pure plea is a term of art from the classical equity pleading system that largely disappeared when equity and law merged procedurally in the United States under the Federal Rules of Civil Procedure (1938) and in England under the Judicature Acts (1873–75). Researchers encountering this term will almost always be working in historical chancery records, pre-merger equity reports, or treatise literature predating procedural fusion.
Several research traps apply. First, the term appears almost exclusively in equity contexts; do not import it into common law pleading analysis. The common law had its own plea taxonomy (pleas in bar, pleas in abatement, etc.) that runs on different principles. Second, historical reporters and digests frequently index pure pleas under "Equity Pleading" or "Plea in Equity" rather than under "Pure Plea" as a standalone head — a researcher who searches only the latter may miss significant treatment. Third, because procedural fusion eliminated the formal need for this category, modern secondary literature rarely discusses it except historically; primary equity treatises (Story's Equity Pleading, Mitford's Treatise on Pleadings in Chancery) are the authoritative sources, not modern hornbooks.
For corpus researchers in Law Mind, pure plea connects most directly to the broader architecture of equity pleading, which structures how defenses were formally presented before a chancellor. Understanding whether a historical defendant filed a pure plea, a negative plea, or a demurrer is often essential to reading the subsequent procedural posture of a chancery case correctly.
Historical Dictionary Support
Black's Law Dictionary and Bouvier's Law Dictionary are in full agreement on the definition: a pure plea is one relying wholly on matter dehors (outside) the bill, with both sources using the plea of release on a settled account as the illustrative example. This alignment across both dictionaries suggests the definition was well-settled in American equity practice and not a subject of doctrinal dispute.
Bouvier adds the useful clarification that the contrasting category — pleas not pure — is sometimes called "negative pleas," providing the terminological pair that researchers need to navigate historical sources. Black's definition is more compressed but substantively identical.
What neither dictionary fully addresses is the procedural mechanics: how a pure plea was framed, what the defendant was required to swear to, or how the court tested the plea's sufficiency before allowing it to stand. For that operational detail, researchers must turn to equity pleading treatises. Bouvier's internal cross-reference to his own Institutes (n. 4275) points toward that deeper treatment.
Neither source flags the jurisdictional variation that existed in American states in how strictly the pure/impure distinction was maintained, which is a gap for researchers working in state chancery records outside the federal courts.
Jurisdictional Note
The pure plea was a formal category of English chancery practice adopted in American equity courts, but its precise treatment varied by state. Some state courts maintained the distinction rigorously; others collapsed it in practice. After procedural merger, the category ceased to have operative significance, though the underlying defensive logic — raising extrinsic matter to bar a claim — survives in affirmative defenses under modern rules.
Encyclopedia Cross-Reference
The Law Mind Criminal Law Encyclopedia: Arraignment and Entry of Plea (criminal_198) — background on plea concepts generally, though in a criminal rather than equity context.