Definition
In law, extinction refers to the complete termination or annihilation of a right, obligation, interest, or legal relationship, such that it ceases to exist entirely rather than merely being suspended or transferred. It is used most precisely as a synonym for extinguishment, particularly in property and obligation law.
Burrill directs the reader immediately to extinguishment as the operative term of art, treating extinction as its near-equivalent. In context, extinction carries the specific sense of a right or incident being absorbed into or consumed by the subject from which it originally derived — as when a lesser estate merges into a greater one and the lesser vanishes entirely, or when a servitude is extinguished because the dominant and servient tenements come under common ownership.
The maxim Extincto subjecto, tollitur adjunctum — "when the subject is extinguished, the incident ceases" — captures the core legal principle: the extinction of the principal thing operates automatically to extinguish whatever was ancillary or appurtenant to it. The classic illustration given in Burrill is the dissolution of a partnership upon completion of its founding purpose: the legal entity and all of its attendant rights and duties terminate by operation of law.
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Common Language
Modern common usage (Wiktionary): The action of making or becoming extinct; annihilation; also used in biology (species loss), psychology (fading of conditioned responses), and astrophysics.
Historical common usage (Webster's 1913): The act of extinguishing or making extinct; putting an end to light, fire, life, activity, or influence; the state of ceasing to be.
The gap between ordinary and legal usage is subtle but important. In common speech, extinction implies permanent, irreversible disappearance — a dramatic finality. In law, extinction is a technical process with defined causes and effects: a right is extinguished not simply because it has lapsed but because a specific legal mechanism has operated upon it. Whether that extinction is reversible, and what consequences flow from it, depends entirely on the nature of the right and the mechanism. A researcher importing the layperson's sense of absolute finality into a legal context may misread historical sources.
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Common Confusion
EXTINCTION vs. EXTINGUISHMENT: In historical legal dictionaries, these terms are used interchangeably or extinction is treated as the abstract noun while extinguishment is the operative legal category. Modern usage tends to prefer extinguishment in property law (extinction of easements, charges, liens) and to reserve extinction for discourse about obligations and partnerships, particularly in civil law and equity traditions. Neither usage is rigid. Researchers should not assume a meaningful distinction between the two terms merely because a source uses one rather than the other.
EXTINCTION vs. SUSPENSION: Extinction is permanent; suspension is temporary. A right that is suspended continues to exist in abeyance and can revive. A right that is extinguished is gone. Historical sources do not always draw this line clearly, and some older authorities describe what is functionally a suspension as an extinction. Context governs.
EXTINCTION vs. RELEASE: A release is an act by the holder of a right voluntarily surrendering it; extinction may result from a release but also from operation of law independent of any act by the rights-holder. The distinction matters when analyzing whether consideration is required or whether the termination of a right can be undone.
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Why It Matters in Research
Researchers in the Law Mind corpus will encounter extinction most frequently in three contexts: (1) historical discussions of real property, particularly servitudes, charges, and lesser estates absorbed into fee; (2) partnership and obligation law, where the maxim Extincto subjecto, tollitur adjunctum appears as an organizing principle; and (3) equity and chancery materials treating the extinction of equitable claims.
The primary trap for researchers is the inconsistent relationship between extinction and extinguishment across sources. Pre-twentieth-century treatises — including Kent's Commentaries, which Burrill cites in this entry — often use extinction as a heading for what modern hornbooks would call extinguishment by merger, by release, or by operation of law. A researcher indexing by modern terminology may miss relevant material filed under the older vocabulary.
A secondary trap: civil law sources (and equity materials drawing on civilian concepts) treat extinction of obligations as a formal category with multiple recognized modes — payment, novation, confusion, merger, release, and prescription — whereas common law sources reach similar results through different analytical pathways and different terminology. When working across legal traditions, do not assume the extinction of an obligation in a civil law source is equivalent in mechanism or effect to what a common law source calls discharge or extinguishment.
The maxim Extincto subjecto, tollitur adjunctum is worth tracking carefully: it appears across property, partnership, and agency materials as a background principle, and its application explains a number of results that are stated without explanation in older sources.
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Historical Dictionary Support
Burrill's treatment is minimal in direct content — the entry functions primarily as a cross-reference to extinguishment — but the embedded maxim and the partnership illustration carry real doctrinal weight. Burrill cites Justinian's Institutes (3.26.6) for the principal/incident rule and Kent's Commentaries (vol. 3, p. 52, note) for the partnership application. This pairing of civil law foundation and American common law elaboration is characteristic of mid-nineteenth-century American legal dictionaries and signals that extinction, at least in partnership contexts, was understood through a lens partly shaped by civilian categories.
What Burrill does not address — and what later dictionaries handle more fully — is the role of extinction in real property: the extinction of easements by unity of ownership, the extinction of mortgages by foreclosure or redemption, and the extinction of estates by forfeiture or merger. Researchers relying solely on Burrill for property research should supplement with later sources. The partnership and obligation applications, however, are well-supported by the citation trail Burrill provides.
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Jurisdictional Note
The vocabulary of extinction is more prominent in jurisdictions with civil law influence (Louisiana, Quebec, mixed-system states) where extinction of obligations is a codified category. Common law jurisdictions achieve equivalent results under the headings of discharge, extinguishment, or release. Researchers working in Louisiana materials should expect extinction to appear as a term of art in the Civil Code rather than as loose synonymy.
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Encyclopedia Cross-Reference
Law Mind Encyclopedia — Extinguishment
Law Mind Encyclopedia — Merger (Property)
Law Mind Encyclopedia — Dissolution of Partnership
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