Definition
PREDICATE functions in law both as a noun and as a verb, with distinct meanings in each role. Modern usage has added a third, highly specific criminal law sense that dominates contemporary research.
1. As a noun (logical): That which is affirmed of the subject in a logical proposition. In the statement "The law is the perfection of common sense," the phrase "perfection of common sense" is the predicate — the thing said about the subject "law." This logical sense appears throughout legal argumentation and judicial opinions when courts analyze the structure of a claim or the terms of a statute.
2. As a verb (general): To affirm, found, or base something upon something else. A legal argument is "predicated on" a particular rule or set of facts when that rule or those facts form the necessary foundation for the argument. Courts routinely use this construction: a ruling predicated on a constitutional question, a claim predicated on fraud.
3. As an adjective/modifier (criminal law — RICO): In the context of federal racketeering law, a predicate act (or predicate offense) is one of a defined list of criminal offenses that, when committed as part of a pattern, can support prosecution under the Racketeer Influenced and Corrupt Organizations Act (18 U.S.C. §§ 1961–1968). The statute enumerates specific state and federal crimes — including mail fraud, wire fraud, murder, bribery, and extortion — that qualify as predicates. Two or more predicate acts within a ten-year period are required to establish the "pattern of racketeering activity" element of a RICO claim.
Common Language
Modern common usage (Wiktionary): To predicate is to affirm one thing of another, or to base or found something upon a premise.
Historical common usage (Webster's 1913): "To assert to belong to something; to affirm (one thing of another)"; also, "to found; to base" — with the note that the "found or base" sense was marked as characteristically American usage.
The common and general legal meanings of predicate align closely when used as a verb. The gap emerges in the noun form and especially in the RICO context. A researcher encountering "predicate act" in criminal litigation materials is reading a term of art with a precise statutory definition — not a logical or grammatical reference. Nothing in the ordinary English sense of the word signals this criminal law specificity.
Recognized Forms
/SUBTYPES
Predicate act / predicate offense: The criminal law subspecies. Carries statutory meaning under RICO and analogous state racketeering statutes. The list of qualifying predicates is defined by statute; courts do not expand it by analogy.
Predicate question / predicate finding: A threshold determination that must be made before a court proceeds to the main issue. Often appears in evidentiary contexts (e.g., a predicate finding of authenticity before a document is admitted) and in constitutional analysis (a predicate finding of discriminatory intent before heightened scrutiny applies).
Why It Matters in Research
The dominant research hazard with predicate is register confusion. Historical sources — including all four dictionaries in this corpus — define the term exclusively in its logical or general verbal sense. None anticipates the RICO predicate act usage, which emerged from the 1970 enactment of the statute and its subsequent litigation. A researcher working with pre-1970 sources will find no trace of the criminal law sense; a researcher working with post-1980 federal criminal materials will find it everywhere, often without definitional explanation because courts assume familiarity.
When reading judicial opinions or briefs, the sense intended is almost always determinable from context: logic and evidence contexts use the logical or foundational sense; RICO, organized crime, and state racketeering contexts use the statutory sense. The verb construction "predicated on" or "predicated upon" spans all contexts and is generally safe to read as "founded on" or "based on."
For corpus navigation: entries treating predicate in the logical sense will cluster in evidence law, statutory construction, and general civil procedure materials. Entries treating predicate act will appear in federal criminal law, organized crime, civil RICO, and state racketeering analogues. The two populations rarely overlap.
The "predicate finding" usage — a threshold factual or legal determination — is worth flagging separately because it appears across evidence law, constitutional law, and administrative law without always being labeled as such. Courts sometimes use "preliminary finding," "threshold determination," or "foundational question" as synonyms.
Historical Dictionary Support
The four source dictionaries show consistent treatment within a narrow frame. Black's (1st and 2nd editions) and Rapalje & Lawrence each define predicate in its logical sense — the affirmed component of a proposition — and reproduce nearly identical illustrative language drawn from Wharton. Bouvier reduces the entry to the verbal definition only: "to affirm logically." There is no disagreement among sources, but the agreement reflects the term's limited legal salience at the time of compilation.
Rapalje & Lawrence is the most complete of the historical entries, explicitly distinguishing the noun and verb senses. The 2nd edition of Black's adds a case citation — Bourland v. Hildreth, 26 Cal. 232 — demonstrating that even in the nineteenth century, courts were using the logical predicate concept in legal argument, though the case itself is unremarkable as authority on the term.
What all historical sources miss, necessarily, is the transformation of predicate into a statutory term of art. This is not a deficiency in the dictionaries; it is a product of timing. Researchers relying solely on these sources for the meaning of predicate act will not be misled — they simply will not find the answer.
Jurisdictional Note
The RICO predicate act framework is federal, but most states have enacted analogous racketeering statutes with their own enumerated predicate offenses. State predicate lists sometimes differ significantly from the federal list. Researchers working on state civil RICO claims should consult the specific state statute rather than assuming federal predicate definitions apply.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — RICO and Racketeering (for predicate act in criminal and civil racketeering contexts); Elements of a Cause of Action (for predicate findings and foundational determinations in civil litigation).