Definition
To supersede is to displace, annul, suspend, or render inoperative a legal instrument, proceeding, order, or authority by the action of a superior or subsequent one. The term operates in several related but distinct legal contexts:
1. Procedural displacement. One writ, order, or proceeding supersedes another when it has sufficient legal force to suspend or terminate the earlier one. A writ of error, for example, historically superseded execution pending appeal. A supersedeas bond operates on this principle — it stays enforcement of a judgment while review proceeds.
2. Legislative and regulatory preemption. A later statute supersedes an earlier one to the extent of any conflict. A federal regulation may supersede a state rule where Congress has occupied the field. Here "supersede" describes the legal effect of hierarchical authority, not mere chronology.
3. Contractual substitution. A subsequent agreement supersedes a prior one when it entirely replaces it, extinguishing the earlier contract's obligations. Merger and integration clauses in contracts commonly declare that the written agreement supersedes all prior negotiations and understandings.
4. Tort law: superseding cause. An intervening act supersedes the original defendant's negligence when it is sufficiently unforeseeable to break the chain of proximate causation and relieve the original actor of liability. In this usage, "superseding" is a term of art with precise doctrinal consequences — see SUPERSEDING CAUSE and the encyclopedia entry above.
Common Language
Modern common usage (Wiktionary): To take the place of; to displace in favor of itself.
Historical common usage (Webster's 1913): To come or be placed in the room of; to replace; to make void or useless by superior power or by coming in the place of; to set aside; to render unnecessary; to suspend.
The ordinary meaning of supersede implies simple replacement — one thing following another in time. The legal meaning is sharper: supersession carries legal consequence. A later contract supersedes an earlier one not merely because it came second, but because it extinguishes the prior obligations. A superseding cause in tort law does not merely follow the original negligence — it severs the legal relationship between cause and harm. Researchers should resist the intuition that mere chronological sequence is sufficient; legal supersession requires operative legal effect.
Common Confusion
Supersede is frequently used loosely as a synonym for amend, repeal, or replace, but these are distinct operations. Amendment modifies without displacing the whole. Repeal voids without substitution. Supersession displaces by putting something else in the same legal position. In contract drafting, an integration clause declaring that the current agreement "supersedes" all prior agreements extinguishes those prior agreements entirely — this is a stronger effect than a clause merely saying the current agreement "governs" in the event of conflict. In appellate practice, the related noun SUPERSEDEAS is sometimes conflated with a notice of appeal itself; a supersedeas is the instrument that stays enforcement, not the appeal.
Why It Matters in Research
Navigating historical sources. The word "supersede" appears across fundamentally different legal contexts in historical materials — writ practice, bankruptcy procedure, outlawry, and lunacy proceedings — without any signal that the researcher has shifted terrain. A passage about superseding a fiat in bankruptcy has nothing to do with superseding a prior contract; both use the same verb. Reading historical primary sources requires context sensitivity that the dictionary entries themselves do not supply.
Tort law research. The superseding cause doctrine is one of the most consequential — and most contested — areas of negligence law. The terminology shifted across the twentieth century. Older sources speak of "intervening efficient cause" or "independent intervening cause" where modern sources use "superseding cause." Not all intervening causes are superseding causes; the distinction between the two (foreseeability) is the central analytical question. Researchers using pre-1950 sources must be alert to different vocabulary for the same doctrinal problem.
Statutory and regulatory preemption. When researching whether a federal statute supersedes a state law, or whether a later statute supersedes an earlier one, the word "supersede" in a statute's text is legally significant but not always dispositive. Courts have construed supersession clauses narrowly in some fields and broadly in others. Primary source research should focus on the specific preemption language used, not assume that the word "supersede" in one statute means the same thing it means in another.
Writ practice. In the historical common law corpus, "supersede" appears most frequently in the context of writs — superseding execution, superseding process in outlawry, superseding a capias. Researchers working in pre-nineteenth-century English or early American materials will encounter this usage as the dominant one, with the word carrying a specific procedural meaning tied to the writ system that has largely disappeared from modern practice.
Historical Dictionary Support
The historical dictionaries agree at the core: supersede means to stay, suspend, annul, or displace a legal proceeding or instrument by the operation of a superior authority. Black's (both editions) and Rapalje & Lawrence are essentially aligned, each using the outlawry and bankruptcy examples as illustrations. Burrill offers the most analytically precise entry, grounding the term in the concept of superior legal efficacy — "to stay, suspend or discharge some judicial proceeding, by another proceeding of higher efficacy" — and correctly noting that the operative mechanism is hierarchical authority, not mere sequence.
What the historical dictionaries miss almost entirely is the tort law usage. By the time superseding cause became a central doctrine of American negligence law in the early twentieth century, the major historical dictionaries had already fixed their entries around writ practice and procedural displacement. Researchers relying solely on those sources will find no guidance on superseding cause doctrine. The Anderson's entry reproduced here is plainly a misprint or corruption — its text concerns Sunday laws and bears no relationship to the term — and should be disregarded entirely.
Jurisdictional Note
The superseding cause doctrine varies meaningfully across U.S. jurisdictions in how foreseeability is weighted and how the doctrine interacts with comparative fault regimes. Some states have moved away from superseding cause as a distinct defense, absorbing the analysis into proximate cause or comparative fault. Statutory supersession analysis is similarly jurisdiction-dependent: federal preemption doctrine follows its own constitutional framework, while state-to-state conflicts among statutes turn on each state's rules of statutory construction.
Encyclopedia Cross-Reference
Negligence — Intervening and Superseding Causes (The Law Mind Torts & Personal Injury Encyclopedia)