Definition
"By virtue of" is a prepositional phrase used in legal instruments, statutes, and pleadings to express the legal authority, power, or basis upon which an action is taken or a right is exercised. It signals that what follows is the source of legal justification — the instrument, office, rule, or status that enables or compels the act described.
In legal usage, the phrase performs two closely related but distinct functions:
1. By authority of. An officer acts "by virtue of" a warrant, writ, statute, or official position, meaning the document or office is what grants lawful power to act. A sheriff executing a judgment acts by virtue of the writ of execution; the writ is the legal instrument conferring authority.
2. By reason of or as a consequence of. A right arises, a duty attaches, or a status changes "by virtue of" some legal fact, event, or relationship — marriage, contract, appointment, or inheritance. Here the phrase identifies the legal cause or operative basis rather than a discrete instrument of authority.
The distinction matters in context: the first usage (authority of an instrument or office) tends to appear in process, enforcement, and official actions; the second (legal consequence of a fact or relationship) tends to appear in property, contract, and status questions.
Common Language
Modern common usage (Wiktionary): Originally, "by the authority or power of"; now more broadly "because of; on the grounds of; by reason of."
Historical common usage: The phrase carried a stronger connotation of formal power or invested authority — acting through some vested right or office, not merely as a result of circumstances.
Editorial note: In ordinary modern English, "by virtue of" has weakened to near-synonym for "because of" and is often used informally to mean nothing more than "due to." In legal texts, the phrase retains its weightier function as a term of art signaling lawful authority or operative legal basis. A researcher reading a historical deed, writ, or pleading should not treat the phrase as mere filler — it identifies the precise legal ground for the action described.
Common Confusion
"By virtue of" is sometimes conflated with "pursuant to," but the terms are not interchangeable. "Pursuant to" almost always references a specific statute, rule, or order and signals compliance or conformity with that authority. "By virtue of" is broader: it encompasses authority derived from an office, a status, a relationship, or a legal instrument, and it emphasizes the source of power rather than procedural compliance. A deputy acts pursuant to a statute but by virtue of the office of deputy sheriff. Similarly, "by reason of" (to which Bouvier cross-references this phrase) is purely causal, while "by virtue of" carries the additional suggestion of legal legitimacy or invested power.
Why It Matters in Research
This phrase appears with high frequency across the Law Mind corpus in instruments spanning centuries, and its meaning shifts depending on context and era.
In historical writ and process materials, "by virtue of" is almost always the phrase linking an officer's action to its authorizing instrument. When reading sheriff's returns, tax levies, or officer liability cases, identifying what the officer claimed to act "by virtue of" is often the central legal question — whether the instrument actually conferred the authority asserted was frequently litigated.
In property and conveyancing materials, the phrase appears in chains of title and devises: rights pass "by virtue of" a deed, will, or statute of descent. Reading it carelessly as mere causation can cause a researcher to miss that a specific instrument is being invoked as the operative basis of title.
In constitutional and statutory interpretation, courts have long scrutinized whether an officer or entity actually possessed the authority it claimed "by virtue of" a particular enactment. The phrase thus anchors many official immunity and ultra vires analyses.
Note that Bouvier's entry is unhelpfully thin — the dictionary cross-references only "BY REASON OF" and offers no substantive treatment of the phrase's legal function. Researchers relying solely on Bouvier for this term will find no guidance on its technical role in process and authority questions.
Historical Dictionary Support
Bouvier's Law Dictionary provides no independent definition of "by virtue of," redirecting the reader to "by reason of" without elaboration. This is a notable gap, given the phrase's ubiquity and its technical weight in process law, official authority questions, and conveyancing.
The Wiktionary entry captures the historical-to-modern semantic drift accurately: the original meaning emphasized authority and power; modern common usage has collapsed this toward simple causation. Legal usage, however, has preserved the older, stronger meaning far more faithfully than ordinary English has, which creates a gap between how a modern general reader and a legal reader will interpret the same text.
No divergence among historical legal dictionary sources is identifiable here because Bouvier is the sole historical source available for this term and it offers no substantive treatment. Researchers should supplement with period-specific treatises on writs, process, and official authority when working with historical materials where the phrase appears.
Jurisdictional Note
The phrase functions consistently across common law jurisdictions. However, in civil law-influenced systems (particularly Louisiana), instruments of authority and their operative phrases follow different formal conventions, and "by virtue of" as a term of art in process and conveyancing may carry less technical weight in those materials.