Definition
Rationes (Latin plural) is a term from old English and medieval law referring to the pleadings in a suit — the formal allegations, responses, and arguments exchanged between parties in litigation. The term derives from the Latin *ratio* in its sense of a reasoned account or formal statement, and in procedural usage it denoted the structured oral and written contentions that constituted pleading before common law courts.
Two related phrases appear in historical sources: *rationes exercere*, meaning to plead or to conduct pleadings, and *ad rationes stare*, meaning to stand to one's pleadings or to maintain one's allegations before the court.
The term belongs to the Latin vocabulary of early English legal procedure and has no living equivalent in modern practice. Contemporary pleadings law uses English-language terminology — complaint, answer, reply, motion — drawn from procedural codes rather than from the Latin pleading tradition.
Common Confusion
Researchers occasionally encounter *rationes* in proximity to *ratio decidendi* (the legal principle upon which a decision rests) and may conflate the two. They are unrelated in legal function. *Rationes* refers to the procedural act of pleading — what the parties put before the court. *Ratio decidendi* refers to the judicial reasoning that resolves the dispute — what the court derives from its analysis. A Wiktionary gloss treating *rationes* simply as the plural of *ratio decidendi* collapses this distinction and should not be relied upon for historical legal research.
Why It Matters in Research
Researchers working in pre-modern English legal records — Year Books, plea rolls, early Chancery records, or treatises predating Blackstone — will encounter *rationes* and its related phrases as standard procedural vocabulary. The term signals that a source is describing the pleading stage of litigation, not the judgment or the underlying substantive law.
The principal trap is the modern reflex to read *ratio* as shorthand for *ratio decidendi*. In a Year Book passage or early common law treatise, *rationes* almost certainly refers to pleadings, not to decisional reasoning. Misreading the term can cause a researcher to treat a description of pleading procedure as a statement about judicial precedent — a significant interpretive error.
A secondary trap: Black's 2nd edition appends the entry for RATTENING immediately after RATIONES without clear typographic separation. Researchers scanning the page may conflate the two entries, which are entirely unrelated. RATTENING is a Victorian English labor offense (trade union coercion involving seizure or concealment of a workman's tools or property); it has no procedural or Latin-law connection to *rationes*.
Because *rationes* as a live term of art disappeared with the Latin pleading tradition, it will not appear in modern procedural codes, civil rules, or contemporary case law. It surfaces almost exclusively in historical legal sources, treatises on common law procedure (such as those drawing on Bracton or Glanvill), and legal dictionaries organized around the Latin vocabulary of the medieval courts.
Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the sole dictionary entry in the Law Mind corpus for this term. The definition is brief but accurate: *rationes* means the pleadings in a suit, with the two Latin phrases (*rationes exercere* and *ad rationes stare*) confirming the term's procedural function.
What Black's does not supply — and what no single short-form dictionary entry can supply — is the broader procedural context. In the oral pleading system of early common law, *rationes* referred to the exchange of formal allegations that occurred before the court and that defined the issue to be tried. The term thus captures something closer to what modern lawyers would call issue-framing than the modern conception of written pleadings. This nuance is absent from Black's entry and must be recovered from treatises on historical common law procedure.
No other historical dictionary in the Law Mind corpus separately defines *rationes*, reflecting the term's status as specialized Latin procedural vocabulary rather than a general legal concept with a contested or evolving meaning.
Encyclopedia Cross-Reference
The Law Mind Constitutional Law Encyclopedia entries on rational basis review (constitutional_195, constitutional_77) are not relevant to *rationes*. No Law Mind Encyclopedia entry is a natural match for this term.