Definition
Latin: "I am not informed" or "I have not been instructed." A formal procedural declaration made by a defendant's attorney stating that he has received no instructions and has no answer to offer on behalf of his client. Upon this announcement, the court enters a species of judgment by default against the defendant. In practice, non sum informatus was not a genuine admission of ignorance but a procedural mechanism — the declaration typically signaled a pre-arranged concession between the parties, allowing judgment to be entered without a contested hearing. It functioned, in effect, as a consensual default.
Common Confusion
Non sum informatus is most frequently confused with two closely related default mechanisms:
NIL DICIT ("he says nothing") arose from a defendant's failure to plead after appearing, without any attorney declaration. Non sum informatus required an affirmative in-court statement by counsel; nil dicit did not. In historical records, the two can be difficult to distinguish without the underlying procedural context.
COGNOVIT ACTIONEM ("he has confessed the action") was an explicit acknowledgment by the defendant that the plaintiff's claim was well-founded. Non sum informatus was not a confession of the merits — it was simply a refusal to defend, often for tactical or settlement reasons. The legal and practical effects could overlap, but the procedural posture was different.
Why It Matters in Research
This term is virtually extinct in modern practice, which means researchers encountering it will almost always be working in historical English common law sources — pleading records, early treatises, and court proceedings from roughly the seventeenth through nineteenth centuries. Several navigational points matter:
First, the term belongs to the vocabulary of formal common law pleading, a procedural world that was systematically dismantled in England by the Common Law Procedure Acts of the mid-nineteenth century and in American jurisdictions through Field Code reforms and eventually the Federal Rules of Civil Procedure. After those reforms, the concept disappears from practice, though it may appear in treatises and digests published for decades afterward as historical reference.
Second, researchers should understand that non sum informatus was a term of art with a specific procedural meaning that differed from an ordinary default judgment. An ordinary default arose from a defendant's failure to appear or respond; non sum informatus arose from an affirmative, in-court declaration by counsel. This distinction matters when reading historical pleading records — the presence of this term tells you that an attorney was present, counsel had made a deliberate choice, and in most cases the parties had privately agreed to the outcome beforehand. It is a signal of collusion or settlement, not abandonment.
Third, the term may appear abbreviated or paraphrased in court records. Clerks sometimes entered only the Latin phrase, sometimes a translated gloss, and sometimes simply "judgment by default on non sum informatus." Cross-referencing against the procedural manuals in use at the time — particularly Tidd's Practice and Blackstone's Commentaries — will clarify local usage.
Fourth, this term connects to the broader corpus of default judgment procedure and the historical mechanics of judgment by nil dicit (he says nothing) and cognovit actionem (he has confessed the action). These three mechanisms — non sum informatus, nil dicit, and cognovit — operated in overlapping territory and are frequently confused in secondary literature.
Historical Dictionary Support
The historical dictionaries are consistent on the core meaning, which reflects the term's narrow, fixed procedural function. Both editions of Black's define it as "I am not informed; I have not been instructed" and characterize it as "a species of judgment by default" entered when the defendant's attorney announces he has no answer to give, usually pursuant to prior arrangement between the parties. The two editions track each other closely, suggesting no significant evolution in understanding between their publication dates.
Burrill's Law Dictionary is the most substantively useful of the shelf sources here. It confirms the definition and the consensual character of the mechanism, citing Blackstone's Commentaries (Book 3, at page 397) and Tidd's Practice (volume 2, at page 930) — both primary treatise authorities for common law procedure. Burrill's explicit statement that non sum informatus "is said to be used only in cases where judgment is entered in pursuance of a previous agreement between the parties" is the clearest articulation of the term's practical significance and distinguishes it from a true involuntary default.
Rapalje & Lawrence does not provide a useful entry for this term; the excerpt in the source material concerns informers and is unrelated.
None of the historical dictionaries address the term's disappearance from practice or its relationship to procedural reform — a gap researchers should keep in mind. The dictionaries treat it as a live procedural term, which reflects their era of composition but does not signal current relevance.
Jurisdictional Note
Non sum informatus was a creature of English common law pleading practice and was carried into early American courts that followed common law forms. Its availability and precise effect varied by jurisdiction depending on local rules and the degree to which courts followed English precedent. It was effectively eliminated wherever code pleading replaced common law forms, beginning in New York in 1848 and spreading through most American jurisdictions over the following decades. Researchers working in American records after approximately 1880 are unlikely to encounter the term in active use.