Definition
Simplex justiciarius is a Latin designation historically applied to any puisne judge — that is, a judge of inferior or subordinate rank — who did not hold the position of chief in a court. The term distinguishes ordinary associate judges from the presiding or chief judge of a given tribunal. It was a formal style of address and reference, not a substantive office or title conferring distinct powers.
Common Confusion
Simplex justiciarius is sometimes loosely equated with "puisne judge" as if the two terms were interchangeable synonyms. They are closely related but not identical. Puisne judge describes the rank itself — the office of a judge who is subordinate to the chief. Simplex justiciarius was the formal style or manner of reference applied to such a judge. The distinction matters in archival research: puisne appears in commission language and statutory contexts well into the modern era, while simplex justiciarius is strictly a historical style that does not persist in post-seventeenth-century usage.
Why It Matters in Research
Researchers encountering this term in historical legal records, pleadings, or treatises should treat it as a marker of judicial hierarchy rather than a named office. It tells you that the judge in question was not the chief justice or presiding judge of his court, but it does not, by itself, identify which court, which jurisdiction, or which period is involved. Because the term appears primarily in older English legal sources and was carried into early American legal writing by compilers drawing on English authority, it will surface most often in pre-nineteenth-century materials. By the time American courts had consolidated their terminology, the phrase had fallen out of active use; modern legal writing has no equivalent, having replaced the concept with "associate justice," "puisne judge," or simply a numbered designation. A researcher who finds the term in a document should not infer anything about the judge's substantive authority beyond his subordinate rank.
Historical Dictionary Support
Both Rapalje & Lawrence and Bouvier's Law Dictionary give nearly identical entries, each citing Cowell as the ultimate authority. The near-verbatim agreement between the two dictionaries is itself informative: neither compiler added independent analysis, which suggests the term was already archaic when both works were written and that no living practice required elaboration. Cowell's Interpreter (1607) is the original locus of the definition, making this a term whose entire documentary life is essentially antiquarian by the time it reaches American legal dictionaries. Neither source situates the term within any procedural or jurisdictional framework, and neither indicates whether the style carried any formal legal consequence. Researchers should not expect to find the term doing substantive legal work in any authority later than the seventeenth century.
Jurisdictional Note
The term is exclusively English in origin and usage. It was never adopted as a formal designation in American courts, though American legal dictionaries preserved it as a historical entry. Researchers working in American sources will find it only in dictionaries and treatises, never in court records or statutes.