Definition
A Latin term meaning baseness, infamy, immorality, or moral depravity. In legal usage, turpitudo denotes the quality of conduct so contrary to justice, honesty, or accepted moral standards as to render the actor legally disadvantaged — most commonly by barring evidence, disqualifying a witness, or voiding a transaction tainted by it. The term does not stand alone as a cause of action or independent legal standard but functions as a qualifying concept embedded in doctrines governing contracts, evidence, and equity. Its modern English descendant, "turpitude," carries essentially the same legal freight and appears far more frequently in contemporary legal texts.
Common Language
Modern common usage (Wiktionary): "Turpitude" — wickedness, depravity, or shameful vileness of character or conduct.
Historical common usage (Webster's 1913): "Turpitude" — inherent baseness or vileness of principle, words, or actions; wickedness; depravity.
The common meaning and the legal meaning are closely aligned in substance, but the legal deployment is more precise: turpitudo is not merely a moral judgment but a technical classification that triggers specific legal consequences. Conduct labeled turpis in a legal context has concrete procedural and substantive effects — blocking a claim, impeaching a witness, or defeating a contract — that the ordinary moral sense of the word does not convey.
Common Confusion
Turpitudo is the Latin root form; turpitude is its direct English derivative and the form researchers will almost always encounter in modern case law, statutes, and secondary sources. The phrase "moral turpitude" — not turpitudo — is the operative legal term of art in contemporary immigration law, criminal law, and professional licensing. Researchers should not treat turpitudo as a discrete legal doctrine distinct from moral turpitude; it is the same concept in its classical Latin form, appearing primarily in historical sources, maxims, and civil law texts. Conflating the raw Latin term with the modern doctrinal category of moral turpitude is the primary research hazard.
Why It Matters in Research
Researchers will encounter turpitudo almost exclusively in Latin maxims embedded in historical treatises, early common law decisions citing civil law authority, and the glossary apparatus of older dictionaries. It does not appear as a freestanding headword in modern practice materials. The practical research path runs from turpitudo in historical sources to moral turpitude in modern doctrine.
The maxim nemo allegans suam turpitudinem est audiendus — no one alleging his own baseness is to be heard — is the most consequential doctrinal use of the term and deserves particular attention. This maxim underlies the in pari delicto defense and the broader equitable principle that courts will not assist a party whose claim rests on their own wrongdoing. Researchers tracing in pari delicto to its historical foundations will pass through this maxim and, by extension, the concept of turpitudo.
When reading decisions from the eighteenth or early nineteenth century that deploy turpitudo or turpis, be alert to the civil law (Roman law) background of the passage. English and American courts borrowing from civilian sources used these Latin terms as a shorthand for the civilian doctrine of turpis causa — a base or immoral consideration that could void a contract — which maps imperfectly onto common law consideration doctrine. Do not assume identical legal effect simply because the same Latin root appears.
The maxim tuta est custodia quae sibimet creditur — that guardianship is secure which is entrusted to itself alone — appears in both Black's editions immediately following the definition of turpitudo. This placement is an artifact of alphabetical proximity in the source texts, not a substantive connection. Do not read the maxim as a gloss on turpitudo.
Historical Dictionary Support
Black's Law Dictionary (1st and 2nd editions) define turpitudo identically: baseness, infamy, immorality, turpitude. Both editions append the maxim tuta est custodia quae sibimet creditur with a citation to Hobart 340, which is a purely positional coincidence and unrelated in substance.
Burrill's Law Dictionary is the most substantively useful of the three sources for this term. Burrill traces turpitudo to turpis (the adjective form), supplies the nemo allegans suam turpitudinem est audiendus maxim with attribution to Calvinus's Lexicon Juridicum, and provides the clearest statement of the maxim's practical effect: no party may ground a legal claim on the allegation of their own infamous or base conduct. This is the doctrinal core that carries forward into modern in pari delicto and unclean hands analysis.
None of the three historical dictionaries address the immigration-law dimension of moral turpitude, which is a later statutory development irrelevant to their period of publication but central to modern practice.
Jurisdictional Note
Turpitudo as a Latin term of art is not jurisdiction-specific. However, moral turpitude — its operational English descendant — varies significantly in definition and application across federal immigration law, state criminal law, and state bar admission standards. Researchers moving from historical turpitudo sources into modern doctrine must account for these divergences rather than assuming a unified definition.