Definition
A Latin phrase meaning "of counsel" or "concerning counsel." It appears in two distinct legal contexts in the historical record:
1. In old criminal law: A designation indicating that a person was privy to the advice, planning, or counsel behind the commission of a crime — that is, a participant not necessarily as a principal actor but as one who counseled or advised the criminal act. This usage signals complicity through advice rather than direct action.
2. In old civil and procedural practice: A statement that an attorney, judge, or other legal figure was "of counsel" for a party in a proceeding — meaning they served in an advisory or representative capacity on one side of the matter. Burrill records a period use from Dyer: a serjeant who had drawn a scire facias was described as having been "de consilio petentis" — of counsel for the petitioner — a fact relevant to his subsequent role in the matter.
Recognized Forms
/SUBTYPES
DE CONSILIO CURIAE — A related phrase meaning "by the counsel of the court," indicating that an act was done on the court's own direction or advice rather than at the instance of a party. Burrill notes this form, though his entry is truncated in available sources.
Why It Matters in Research
Researchers encountering de consilio in historical sources must determine which of the two meanings applies from context. The criminal law usage — found in Fleta — signals a mode of accessory liability based on counsel or advice, relevant to how pre-modern English law parsed complicity. The procedural usage — appearing in Year Book-era records and Dyer — is a professional designation marking counsel's relationship to a party, akin to a conflict-of-interest notation.
The criminal law sense is the more frequently cited definition in American legal dictionaries, but researchers working in older English reports and Year Book materials will encounter the procedural sense far more often in practice. Both Black's editions lead with the criminal law definition and omit the procedural sense entirely; Burrill is the more complete source here.
The phrase also belongs to a cluster of Latin "de" designations — de facto, de jure, de novo — that researchers may encounter in proximity without recognizing de consilio as a distinct term of art rather than a descriptive phrase.
For modern research purposes, de consilio has no living doctrinal application. It appears in historical secondary sources, treatises tracing the development of accessory liability, and in annotations to old English reports. Researchers tracing the intellectual genealogy of accomplice liability or attorney disqualification based on prior representation may find the phrase as a terminus a quo in the older literature.
Historical Dictionary Support
Black's (both editions) treats de consilio as exclusively a criminal law term, citing Fleta, lib. 1, c. 31, § 8 — a thirteenth-century Latin treatise on English law attributed to an unknown author, likely written during the reign of Edward I. The Fleta citation grounds the term firmly in the period before the more developed common law categories of principal and accessory solidified.
Burrill is the superior source for this term. He records both the criminal and the procedural meanings, supplies a dated example from Dyer (the Year Book-era English reporter Sir James Dyer), and cross-references the related Latinism A consiliis as well as the English equivalent "De counsel." Burrill's entry also introduces DE CONSILIO CURIAE as a distinct sub-form, which Black's does not address. Researchers relying solely on Black's will miss the procedural sense and the court-counsel variant entirely.
No modern American legal dictionary of general circulation carries this term as a live entry, which accurately reflects its status as a historical archaism.
Jurisdictional Note
De consilio is a term of historical English law with no current jurisdictional application in U.S. or English courts. It is encountered only in scholarly, historical, and antiquarian legal research contexts.