Definition
A Latin adverb of medieval legal usage meaning "incidentally" or "by the way." In classical Roman and medieval common law Latin, *incidentaliter* signified that a matter was being raised or decided not as the principal subject of proceedings but as a collateral or ancillary point arising from them. A court or pleader proceeding *incidentaliter* addressed something as a side consequence of the main issue rather than as a direct object of inquiry or relief.
The term belongs to the vocabulary of scholastic and ecclesiastical legal reasoning that passed into English common law through Bracton and the broader tradition of learned Latin pleading. It contrasts implicitly with terms denoting principal or direct treatment of a matter — where a question is taken up *incidentaliter*, its resolution is subsidiary, and any finding on it may carry less conclusive weight than a determination made as the central issue of the proceeding.
Why It Matters in Research
The primary research value of *incidentaliter* is its appearance in Bracton's *De Legibus et Consuetudinibus Angliae*, the foundational thirteenth-century treatise on English common law. Burrill's reference to Bracton fol. 247b places the term in a specific doctrinal context. Researchers working with Bracton — whether in Latin or in Thorne's modern English translation — will encounter this and similar adverbial qualifiers that signal how the medieval jurist distinguished between binding determinations and collateral observations. Treating such qualifications as mere stylistic ornament will cause a researcher to misread the logical structure of Bracton's argument.
More broadly, *incidentaliter* belongs to a family of medieval Latin adverbs — alongside *principaliter*, *specialiter*, and *generaliter* — that Bracton used to organize legal reasoning. Recognizing this vocabulary is necessary for accurate interpretation of the original text and for understanding which propositions Bracton intended as authoritative rules versus which were illustrative digressions.
The concept behind the word also has long doctrinal life under English terms. The distinction between a matter decided directly and one decided only incidentally became central to the law of *res judicata* and collateral estoppel — a court's incidental finding on a point not directly at issue has historically been accorded less preclusive effect than a finding essential to the judgment. Researchers tracing that doctrine to its common law roots may find *incidentaliter* a useful conceptual marker even when later sources have abandoned the Latin form.
There is minimal risk of encountering this term outside of Bracton and texts directly commenting on him. It is not a term of art in pleading practice manuals, statutes, or modern case law. Its significance is almost entirely textual and historical.
Historical Dictionary Support
Burrill's entry is spare: a single Latin adverb, a one-word English gloss ("incidentally"), and a pinpoint citation to Bracton. This brevity is appropriate to the term's narrow scope — *incidentaliter* is a grammatical qualifier rather than a freestanding legal doctrine, and Burrill rightly declines to inflate it.
No substantive elaboration appears in the major historical dictionaries. Bouvier does not carry an entry. Black's early editions omit it. This is consistent with the term's limited circulation: it is a Bractonian usage rather than a term of general pleading or practice, and dictionary compilers writing for practitioners had little reason to include it.
What the historical sources collectively miss is the interpretive significance of the qualifier within Bracton's method. Bracton's Latin prose is structured in part through such adverbs to signal the logical status of each proposition. A reader unfamiliar with this technique may treat an *incidentaliter* passage as carrying the same doctrinal weight as Bracton's direct holdings — an error that Burrill's definition, though technically accurate, does nothing to prevent.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Pleading (for the role of Latin adverbial qualifiers in medieval common law pleading); Jurisdiction (for the modern doctrinal descendant of the incidental/principal distinction in questions of ancillary and pendent jurisdiction).