Definition
Latin: "a contract; contracts." The Roman law term for a legally recognized agreement creating binding obligations between parties. In classical Roman and civil law usage, contractus referred to the formal category of obligatory agreements — those recognized by law as enforceable — as distinguished from mere informal pacts (pacta) that did not independently generate a right of action.
The term appears in Anglo-American legal sources primarily in two contexts: (1) as shorthand in Latin maxims and brocard citations carried over from Roman and civil law, and (2) as a classifier in the distinction between obligations arising ex contractu (from contract) and those arising ex delicto (from wrongful act or tort).
Sub-definitions:
1. Contractus bonae fidei — "Contracts of good faith." In Roman law, a recognized category of contracts adjudicated not solely by the strict rules of law (stricti juris) but with latitude for the judge to examine the honesty of the transaction and entertain equitable objections. Opposed to contracts stricti juris, which were enforced rigidly according to their letter.
2. Contractus ex turpi causa — A contract founded on a base or immoral consideration. The maxim "Contractus ex turpi causa, vel contra bonos mores, nullus est" (a contract grounded on a base consideration, or against good morals, is void) is the civil law parallel to the common law doctrine of illegal consideration. The broader civil law formulation is "Pacta quae turpem causam continent non sunt observanda" — agreements resting on a corrupt basis are not to be kept.
3. Ex contractu — "By virtue of a contract." Describes rights, duties, and causes of action arising from a contractual relationship, as opposed to ex delicto, which describes rights and duties arising from a tort or wrongful act. The distinction shaped classical procedural classifications: actions ex contractu and actions ex delicto.
Common Confusion
Contractus is not interchangeable with the English word "contract" in legal research, even though it translates directly as such. The Latin term carries the full weight of Roman law classificatory theory — including the bonae fidei / stricti juris division and the ex contractu / ex delicto procedural taxonomy — which the English word "contract" does not imply. Researchers encountering contractus in historical sources should read it within its Roman or civil law framework, not through the lens of modern common law contract doctrine.
Why It Matters in Research
The primary research value of contractus lies in tracing doctrine from civil law and Roman law sources into Anglo-American legal writing. Courts and treatise writers through the nineteenth century regularly cited Latin maxims in their original form, and contractus appears in this context far more often than in modern usage.
Key navigational points:
Older English and American cases frequently invoke maxims like "contractus ex turpi causa nullus est" without translation, assuming reader familiarity. Researchers working in equity, commercial law, or contract validity doctrine in sources predating 1900 should recognize these formulations as carrying substantive legal content, not mere ornamentation.
The ex contractu / ex delicto distinction is foundational to understanding how nineteenth-century courts classified causes of action and forms of pleading. A right or action described as sounding ex contractu was treated differently in procedure, limitation periods, and available remedies from one sounding ex delicto. This classification appears throughout older treatises on pleading and practice.
The bonae fidei / stricti juris distinction does not map cleanly onto common law doctrine. Common law did not formally adopt this Roman law division, but civil law influence is visible in equity's willingness to scrutinize the fairness of agreements that strict courts would enforce. Researchers tracing the historical roots of unconscionability doctrine or equitable defenses to contract enforcement will find the bonae fidei concept instructive.
In comparative law research and international commercial contexts, contractus appears in civil law materials where it retains full technical precision.
Historical Dictionary Support
The historical dictionaries converge on the core definition without meaningful disagreement. Black's (both editions) and Burrill define contractus as "contract; a contract; contracts" and develop the sub-entries (bonae fidei, ex turpi causa) consistently with Roman law sources. Anderson's is the most useful for the ex contractu / ex delicto distinction, explicitly framing it as a procedural and obligatory classification and noting that civil law places the greater part of rights and duties under obligations ex contractu.
Burrill's entry is notable for quoting the turpi causa maxim with its Hobart citation (Hob. 167) and its civil law parallel, demonstrating the crossover between Roman maxim and English common law application.
What historical dictionaries underemphasize: none of the dictionary entries fully articulate the procedural consequences of the ex contractu / ex delicto distinction for Anglo-American pleading practice. Researchers needing that layer should turn to nineteenth-century treatises on common law pleading rather than dictionary sources alone.
Jurisdictional Note
Contractus as a technical term has no jurisdiction-specific meaning in modern American or English law — it is a Roman and civil law term that migrated into Anglo-American legal writing through maxims and scholarly citation. Louisiana and Quebec, as civil law jurisdictions, retain the underlying conceptual framework most directly. In common law jurisdictions, the doctrine survives in translated form through the law of illegal contracts and equitable defenses.
Encyclopedia Cross-Reference
The Law Mind Contracts & Commercial Law Encyclopedia: Discharge -- Bankruptcy and Discharge of Contractual Obligations.