Definition
En certein (Law French: "in certain") is a term of Law French meaning reduced to certainty, or put in certain terms. It describes the act of fixing, specifying, or rendering definite something that was previously uncertain or indefinite — particularly a sum, quantity, obligation, or legal claim. Where a right or demand existed in an unliquidated or general form, it was said to be put en certein when expressed in precise, determinate terms.
Why It Matters in Research
This is a term of art from the Law French layer of medieval English legal writing, and its appearance in sources is almost entirely confined to early treatises and Year Books. Researchers encountering en certein in historical materials should recognize it as a procedural or drafting concept, not a substantive doctrine: the concern is whether a pleading, writ, or obligation has been stated with sufficient precision to be actionable or enforceable. The concept maps loosely onto the modern requirement of certainty in pleading and the distinction between liquidated and unliquidated claims, but no direct doctrinal lineage should be assumed without tracing the specific context.
The term appears in Britton (the late 13th-century legal treatise compiled in Law French), which is the primary source Burrill references. Researchers working with Britton or related medieval English legal texts will encounter Law French phrases of this pattern frequently. The phrase mys en certein — "put in certain," Burrill's specific gloss — signals an active transformation: something has been reduced from vague to definite, from general to specific.
Because Law French terms were absorbed unevenly into English legal vocabulary, en certein did not persist as a technical term in common law jurisdictions beyond the medieval period. Its functional successor concepts — certainty in pleading, liquidated damages, specification of demand — carry the same operational meaning in modern practice but without the phrase itself. A researcher finding this term should not search modern digests or indices for it; the research path runs through medieval and early modern sources exclusively.
Historical Dictionary Support
Burrill's entry is spare: "In certain. Mys en certein; put in certain; reduced to certainty. Britt. c. 69." This is characteristic of Burrill's treatment of Law French procedural terms — the gloss is translational rather than analytical. The entry confirms the term's medieval provenance and its grounding in Britton, one of the foundational treatises of early English common law. No broader doctrinal context is offered.
Historical dictionaries covering Law French legal vocabulary (such as those by Kelham and Termes de la Ley) treat similar phrases under the general taxonomy of certainty and pleading requirements, but en certein as a discrete entry is not prominently featured outside Burrill. This suggests the term functioned more as a descriptive phrase in text than as a standalone technical term with its own body of doctrine. Researchers should treat it accordingly — as a linguistic marker of a legal concept rather than a term with independent doctrinal weight.
Jurisdictional Note
En certein is a feature of the medieval English common law tradition and has no meaningful presence in American, Scottish, or civilian legal sources. Its relevance is confined to English legal history and to materials derived from or commenting on early English practice.