Definition
In law, "instantaneous" describes an act, event, or crime that is complete in a single, indivisible moment — one that is fully consummated by a single act rather than unfolding across a series of acts or an extended period. The concept most frequently appears in criminal law and in limitations doctrine.
1. Instantaneous crime. A crime whose commission is complete the moment the prohibited act occurs. Arson and murder are the canonical examples: the act that constitutes the offense is singular and discrete. Once done, the offense is over. This stands in contrast to continuing offenses, where the criminal conduct persists over time.
2. Instantaneous injury or wrong. In tort and limitations analysis, harm or a wrongful act that occurs at a single, identifiable moment. The distinction matters for when a cause of action accrues and when the limitations clock begins to run.
Common Language
Modern common usage (Wiktionary): Occurring, arising, or functioning without any delay; happening within an imperceptibly brief period of time.
Historical common usage (Webster's 1913): Done or occurring in an instant, or without any perceptible duration of time; as, the passage of electricity appears to be instantaneous.
The common meaning focuses on speed — something so fast it appears to have no duration. The legal meaning shifts emphasis from speed to structure: what matters legally is not how quickly the act occurs, but whether it is singular and complete rather than repeated or ongoing. A slow-burning arson fire may take hours, yet the criminal act of setting it is legally instantaneous. Researchers conflating the ordinary and legal senses will misread arguments about crime classification and limitations periods.
Common Confusion
INSTANTANEOUS vs. CONTINUING. These are paired opposites in criminal law and limitations doctrine. An instantaneous offense is consummated in a single act; a continuing offense involves repeated or ongoing conduct that extends the period of criminal liability. The distinction governs venue (where the crime may be prosecuted), double jeopardy analysis, and, critically, when statutes of limitations begin and stop running. Sources that use "instantaneous" loosely to mean "very fast" obscure this structural distinction.
INSTANTANEOUS vs. PERMANENT. In nuisance and property tort doctrine, a permanent wrong (sometimes called a permanent nuisance) is a single, complete invasion whose full extent is apparent from the start, allowing one action for all damages. Courts have not uniformly treated "instantaneous" and "permanent" as synonyms; the two concepts overlap but are analytically distinct. Research crossing these doctrines requires attention to which label a given jurisdiction applies.
Why It Matters in Research
The term "instantaneous" is a structural classifier, not merely a descriptor of speed. Its legal significance clusters in three research areas:
Statute of limitations. Whether a wrong is instantaneous or continuing controls when the limitations period begins. For an instantaneous wrong, the clock starts at the moment of the act; for a continuing wrong, the period may be tolled or reset with each repetition. Early cases and treatises often use "instantaneous" without fully developing this limitations dimension, so researchers working backward through historical materials must read the surrounding doctrine rather than relying on the label alone.
Criminal venue and double jeopardy. Instantaneous crime doctrine determines where prosecution may be brought and whether a second prosecution is barred. Historical sources, including Black's 2nd Edition, address the crime-classification function but rarely develop the venue or double jeopardy implications at length. Later editions and treatises on criminal procedure fill this gap.
Tort accrual. The instantaneous/continuing distinction in tort mirrors the criminal doctrine but developed on a separate track. Researchers moving between criminal and civil sources should not assume that a court's use of "instantaneous" in one context maps cleanly onto the other.
The U.S. v. Owen citation in Black's 2nd Edition (D.C., 82 Fed. 537) is one of the few contemporaneous federal sources explicitly applying the instantaneous crime framework; it provides a useful anchor for late nineteenth-century usage.
Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the clearest historical legal articulation: an instantaneous crime is one "fully consummated or completed in and by a single act," with arson and murder as illustrative examples. This framing centers the concept on completeness and unity of act, not on temporal duration in the ordinary sense.
What historical dictionaries leave undeveloped: the relationship between instantaneous-crime doctrine and statutes of limitations, and the growing body of continuing-offense doctrine that would later demand a more rigorous definition of the concept's opposite. Black's 2nd Edition entry is definitionally useful but analytically thin by the standards of later criminal law scholarship. Researchers relying solely on the historical dictionary entry will have the framework but will need to supplement it with case law and treatises to apply it to limitations or venue questions.
Jurisdictional Note
Instantaneous crime doctrine is general common law, but its application in limitations and venue contexts varies by jurisdiction and statutory scheme. Federal courts have developed continuing-offense doctrine under specific statutes (conspiracy, RICO) that affects how "instantaneous" is implicitly defined by contrast. State courts in property and nuisance law have used the term differently than criminal courts, sometimes equating it with "permanent" for accrual purposes.