Definition
In law, conventional means arising from, or dependent upon, the mutual agreement of the parties, as distinguished from legal, which means arising from the operation or construction of law. Where a right, obligation, estate, or remedy is described as conventional, the source is the parties' own act — their contract, compact, or agreement — rather than any rule imposed by statute or common law.
The term appears most frequently as a modifier rather than a standalone noun:
1. Conventional mortgage: A mortgage loan made without government insurance or guarantee — that is, one not backed by the FHA, VA, or similar programs. The loan terms arise from the private agreement between lender and borrower, not from a statutory scheme. This is the most common modern usage.
2. Conventional estate: Historically, an estate for life expressly created by the act of the parties, as distinguished from a legal life estate arising by operation of law (e.g., curtesy or dower at common law).
3. Conventional subrogation: Subrogation that arises by express agreement between the parties, as opposed to legal subrogation, which equity imposes regardless of agreement.
4. Conventional interest: Interest agreed upon by the parties in their contract, as opposed to legal interest fixed by statute.
Common Language
Modern common usage (Wiktionary): Ordinary, commonplace; conforming to accepted norms or practices; banal or unoriginal; also, pertaining to non-nuclear weapons.
Historical common usage (Webster's 1913): Formed by agreement or compact; stipulated; growing out of custom or tacit agreement; sanctioned by general concurrence or usage; formal.
The gap matters. In ordinary speech, conventional has drifted toward meaning unremarkable or standard — the opposite of innovative. In legal usage, the word retains its older, technical sense of arising from agreement (from Latin conventio), and carries no connotation of being ordinary or mundane. A conventional remedy is not a common remedy; it is a remedy the parties have agreed to. A researcher who reads conventional in a historical legal source and interprets it through the modern common-language lens will misread the text.
Common Confusion
Conventional vs. Legal (as paired opposites): In historical legal writing, conventional and legal are used as a matched pair. Legal means arising from the act of law — by statute, by rule of court, or by legal construction. Conventional means arising from the act of the parties. This pairing is essential to understanding historical sources on estates, subrogation, mortgages, and interest. Modern readers accustomed to legal meaning lawful may read the distinction as conventional (ordinary) versus legal (authorized), which reverses the intended meaning entirely.
Why It Matters in Research
The practical importance of conventional varies sharply by subfield and era.
In property research, the conventional/legal distinction governed how life estates and other interests were classified in English common law treatises and early American sources. Blackstone's treatment at 2 Bl. Com. 120 — cited by both Bouvier and Burrill — is the anchor. Researchers reading pre-20th century conveyancing materials, equity opinions, or property treatises will encounter this distinction repeatedly. Missing it produces misreadings of estate classifications.
In mortgage and lending research, conventional has a modern technical meaning — a loan not backed by federal insurance or guarantee — that is entirely absent from 19th-century sources. The term shifted from describing the contractual origin of an instrument to describing its relationship to a regulatory and insurance framework that did not exist until the 20th century. A researcher tracing mortgage terminology across the corpus will cross this divide.
In subrogation and insurance law, conventional subrogation remains an active doctrinal category, distinguished from legal (or equitable) subrogation in opinions and treatises through the present day.
Trap for researchers: Because conventional is always a modifier in legal usage, its meaning depends entirely on what it modifies. Conventional interest, conventional mortgage, conventional estate, and conventional subrogation each carry distinct doctrinal content. The word alone signals only the source — party agreement rather than law — but the substantive rules are term-specific.
Corpus connection: Black's 2nd Edition explicitly cross-references Estates, Interest, Mortgage, Subrogation, and Trustees as entry points. Researchers working from Black's 2nd should follow those cross-references, not rely on the standalone definition.
Historical Dictionary Support
All four source dictionaries converge on the same core definition: conventional means produced by, or dependent upon, the agreement or mutual arrangement of parties, as opposed to legal, meaning created by operation of law. There is no meaningful divergence on this point.
Burrill is the most instructive of the four. His entry roots the term explicitly in the Latin conventio and gives the concrete example of conventional estates for life, anchored to Blackstone. This etymology-to-application structure is useful for understanding why the term appears where it does in historical property law writing.
Bouvier's entry is notable for an editorial artifact: the definition of conventional is immediately followed by a partial entry on contumacy — an artifact of the alphabetical compilation and not a substantive connection. Researchers using digitized versions of Bouvier should be aware of this juxtaposition to avoid misreading.
Black's 1st and 2nd Editions are functionally identical on this term. The 2nd Edition adds the explicit cross-reference list, which is the more useful research tool of the two.
What the historical dictionaries do not address: the modern regulatory meaning of conventional mortgage. That usage is a 20th-century development tied to the creation of FHA and VA lending programs and has no footprint in any of the four source dictionaries.
Jurisdictional Note
The conventional/legal distinction in property and subrogation law is common-law heritage shared across U.S. jurisdictions and traceable to English sources. Conventional mortgage, however, is a term of art in American lending regulation with no direct English counterpart. Researchers working in civil-law jurisdictions (including Louisiana) should note that the conventional/legal pairing maps differently onto civil-law categories, where obligations arising from contract are distinguished from those arising ex lege on different structural grounds.
Encyclopedia Cross-Reference
Conventional Mortgages — Qualification, Underwriting, and Private Mortgage Insurance (The Law Mind Real Estate Transactions & Construction Encyclopedia)
The Amendment Process — Article V, Conventions, and Ratification (The Law Mind Constitutional Law Encyclopedia) [for the distinct term convention as a gathering or assembly, not conventional as a modifier]