Definition
In the civil law, *accidens* (plural: *accidentia*) denotes an accident, event, or circumstance — specifically, a thing that happens or befalls, as distinguished from something essential or inherent. The term carries two related but distinct senses in legal usage:
1. Factual sense: An occurrence or event of a contingent nature; something that comes about by chance rather than by design or necessity.
2. Philosophical-legal sense: A property, quality, or attribute that is nonessential to the substance of a legal thing — something that may or may not be present without altering the fundamental character of the subject. In this sense, *accidens* stands in contrast to *substantia* or *essentia*.
The term appears in civil law commentaries and glossarists primarily as a term of art drawn from scholastic logic and Roman jurisprudence, where it described qualities attaching to a subject incidentally rather than constitutively.
Common Language
Modern common usage (Wiktionary): A synonym of "accident" in its philosophical sense — a property, fact, or relation that results from chance or is nonessential and nonsubstantive.
Historical common usage (Webster's 1913): Webster's does not carry a standalone entry for *accidens*, treating it as the Latin root underlying the English "accident" — an event proceeding from an unknown cause, or an unexpected happening.
The gap here is subtle but real. In ordinary English, "accident" has collapsed almost entirely into its factual sense (an unintended mishap). The legal-civil usage of *accidens* preserved the philosophical sense — a nonessential attribute or quality — that English common usage has largely abandoned. A researcher encountering *accidens* in a civil law treatise should not assume the word means merely "an unfortunate event."
Common Confusion
*Accidens* is sometimes read as a direct equivalent of the English "accident" in the modern negligence sense — an unintended harmful event giving rise to liability. This is a mistaken equation. The civil law term operates at the level of legal and logical classification, not tortious events. When civilians wrote of *accidens* in the philosophical-legal sense, they were addressing whether a given attribute was essential to a legal relationship or merely incidental to it — a question with consequences for contract interpretation, property characterization, and the analysis of legal obligations. The negligence-law concept of "accident" is a separate development in the common law tradition.
Why It Matters in Research
*Accidens* appears infrequently in English-language legal sources but surfaces in translations of Roman law, civil law treatises, canon law commentaries, and early modern natural law writing. Researchers working in the Law Mind corpus should be alert to two navigational challenges:
First, the term is context-dependent. In a passage discussing contractual terms, *accidens* likely signals the philosophical distinction between essential and incidental elements — relevant to debates about what terms could be implied or varied without voiding an agreement. In a passage discussing events in the course of legal proceedings, it may simply mean a contingent occurrence.
Second, the term migrates across disciplines. Scholastic philosophy, Roman jurisprudence, and canon law all used *accidens* in cognate but not identical ways. A passage drawn from a canonist or a natural lawyer may use the term with slightly different weight than a Roman law commentary. Cross-referencing the surrounding doctrinal context is essential.
Corpus researchers will find the term most productive when encountered in glossaries, civilian commentaries, and translated Roman law texts rather than in English common law reports, where it appears rarely and usually only in learned dicta.
Historical Dictionary Support
Burrill's Law Dictionary provides the core entry, defining *accidens* as "an accident; a thing happening; an event or circumstance" and citing Calvinus's *Lexicon Juridicum* and Spiegel's glossary as authorities. This is a reliable but minimal entry. Burrill captures the factual sense adequately but does not develop the philosophical-legal distinction between *accidens* and *essentia*, which is the more analytically significant dimension of the term in civilian scholarship.
The civilian glossarists Calvinus and Spiegelius, cited by Burrill, represent the standard reference tradition for this term in the early modern period. Their treatment situates *accidens* firmly within the scholastic-Roman synthesis that characterized continental legal education through the seventeenth and eighteenth centuries.
No major English legal dictionaries — not Cowell, not Tomlin, not Black's in its early editions — give *accidens* a substantive independent entry, which is itself informative: the term was understood as belonging to the civil law tradition rather than to the common law vocabulary.
Jurisdictional Note
*Accidens* as a term of art belongs to the civil law tradition and has no technical standing in English common law jurisdictions. It remains relevant in jurisdictions with mixed or civilian legal systems — Louisiana, Quebec, Scotland, South Africa — where civilian conceptual vocabulary persists in legal reasoning and academic writing.