Definition
A Latin phrase meaning "base cause" or "vile consideration." In contract and obligations law, a turpis causa is a consideration so contrary to morality, public policy, or law that courts will refuse to enforce any agreement founded upon it. A promise made in exchange for a turpis causa is void — not merely voidable — because the law treats the underlying bargain as one no court should assist in enforcing.
The concept operates most directly through the maxim ex turpi causa non oritur actio: "out of a base cause, no action arises." Where a plaintiff's claim is rooted in an immoral or illegal consideration, the court will leave the parties where it finds them, declining to grant relief to either side.
Classic examples in the historical literature include promises made in exchange for future illicit cohabitation, agreements to commit a crime, and contracts founded on bribery or fraud. The doctrine is not limited to criminal conduct; serious moral turpitude — even absent a penal violation — could historically render a cause turpis.
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Common Language
The term has no meaningful common English counterpart. "Turpis" is classical Latin for base, vile, or shameful; "causa" means cause or reason. Neither word circulates in ordinary modern English, and Webster's 1913 does not treat either as an English entry in a legal sense. The phrase is pure legal Latin and can be omitted from the COMMON LANGUAGE section on that basis.
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Common Confusion
TURPIS CAUSA vs. ILLEGALITY GENERALLY: Researchers sometimes treat turpis causa as synonymous with simple illegality in contract law. The concepts overlap but are not identical. A contract can be unenforceable for illegality — for example, violating a licensing statute — without the underlying consideration being morally base. Turpis causa targets the moral character of the consideration itself, not merely its technical lawfulness. Historically, courts drew this line to explain why some illegal bargains might be severed or partially enforced while bargains resting on turpis causa were refused entirely.
TURPIS CAUSA vs. NULLA BONA CAUSA: A turpis causa is a cause that exists but is wicked; a nulla causa is no cause at all. The legal results differ: absence of consideration raises different defenses than the presence of an immoral one.
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Why It Matters in Research
The phrase appears most frequently in older equity and common law contract cases, and researchers working in historical sources (pre-twentieth century) will encounter it with some regularity. By the mid-twentieth century, Anglo-American courts largely abandoned the Latin phrase in favor of plain-English formulations of the illegality and public policy doctrines, so the term's frequency drops sharply in modern reporters and statutory materials.
Several research traps are worth flagging:
First, the maxim ex turpi causa non oritur actio is the operative principle; turpis causa is the analytical predicate. Searches limited to "turpis causa" alone will miss a large portion of the relevant doctrine. Researchers should run both terms.
Second, equity courts and common law courts historically applied the doctrine with different emphases. In equity, courts invoked the related clean hands doctrine, which is a broader and more flexible instrument. A researcher tracking the evolution of the illegality defense across law and equity must treat these as overlapping but distinct lines of authority.
Third, the scope of what qualified as "base" was not static. Nineteenth-century courts sometimes classified conduct as turpis that modern courts would treat as merely voidable on policy grounds (for example, restraint of trade or Sunday contracts in some jurisdictions). The moral loading of the doctrine was heavier in earlier periods; researchers should not assume that a nineteenth-century turpis causa holding maps neatly onto modern illegality analysis.
Fourth, in the Law Mind corpus the doctrine intersects meaningfully with gift law. A gift made mortis causa (in anticipation of death) is evaluated partly on whether the underlying donative intent is tainted. Researchers working on causa mortis gifts should be alert to cases where courts analyzed whether the "causa" of the gift was itself turpis.
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Historical Dictionary Support
The three source dictionaries are in close agreement on the core definition: turpis causa is a base, vile, or immoral consideration insufficient to support a contract or found an action. Black's illustrates with future illicit intercourse. Burrill provides the most complete statement of the operative maxim and its procedural consequence — that if the turpis causa appears from the plaintiff's own pleading, the court will deny relief.
Rapalje & Lawrence adds two associated maxims (Turpis est pars quæ non convenit cum suo toto and Tuta est custodia quæ sibimet creditur) that appear largely contextual to their arrangement of Latin maxims rather than directly illuminating turpis causa as a standalone doctrine.
What the historical dictionaries do not address: the evolution of the doctrine into modern illegality analysis, the distinction between courts of law and courts of equity in applying the principle, or the severability question — whether a contract containing a turpis causa element could survive if the offending consideration were separated. These are gaps researchers should expect when relying solely on dictionary sources for this term.
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Jurisdictional Note
The doctrine of turpis causa, operating through the ex turpi causa maxim, was received into American common law from English sources and applied broadly in both federal and state courts through the nineteenth century. American jurisdictions varied in how expansively they defined "base" conduct, with some courts limiting the doctrine to criminal or quasi-criminal acts and others applying it to serious moral wrongs. Modern American contract law has largely absorbed the concept into the Restatement framework on illegal bargains and public policy, where it functions without the Latin label.
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Encyclopedia Cross-Reference
Property Law Encyclopedia — Personal Property: Gifts (Inter Vivos, Causa Mortis — Delivery, Intent, Acceptance) [property_133]: Relevant for researchers examining whether the causa in a causa mortis gift is subject to turpis causa analysis, and for the broader role of "cause" or motive in donative transactions.
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