Definition
An action arising from a loan for use (*commodatum*) in Roman civil law. The actio commodati was the procedural vehicle by which the parties to a *commodatum* — a gratuitous loan of a movable object for a specific purpose, to be returned in kind — enforced their respective obligations. It encompassed at minimum two distinct directional claims:
1. Actio commodati directa: The action available to the lender (commodant) against the borrower (commodatary) to compel return of the loaned object and to recover for damage caused by the borrower's fault, gross negligence, or use beyond the terms of the loan.
2. Actio commodati contraria: The action available to the borrower against the lender to recover extraordinary expenses incurred in maintaining or preserving the object during the loan period, or for damages caused by a defective article the lender knowingly or negligently furnished.
The underlying contract of *commodatum* was a gratuitous arrangement: because no price was paid for the use of the thing, the lender was not strictly liable for defects in the same way a vendor might be, but good faith obligations still ran in both directions.
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Recognized Forms
/SUBTYPES
Directa: Lender's claim against borrower. Primary in practice; enforces the borrower's duties of care and restitution.
Contraria: Borrower's claim against lender. Secondary and contingent; arises from the lender's obligations, if any, incurred during the loan.
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Why It Matters in Research
This term appears almost exclusively in civil law scholarship, Roman law treatises, and discussions of the historical foundations of bailment and contract law. Researchers will encounter it primarily in:
- Comparative law works tracing modern bailment doctrine to Roman sources
- Civil law jurisdiction scholarship (Louisiana, Quebec, Scotland, and the mixed legal systems influenced by the *ius commune*)
- Historical treatments of contract classification in the Roman law tradition
The term is essentially dormant in common law practice and modern Anglo-American caselaw. Its presence in Black's and Burrill's reflects the strong Roman law influence on nineteenth-century American legal scholarship and dictionary-making, not active use in contemporary courts or statutes.
The *directa/contraria* distinction is worth noting because it encodes an important structural idea — that even a "one-sided" gratuitous loan could generate enforceable obligations running in both directions — an idea that surfaces in bailment law discussions of the bailor's duties as well as the bailee's.
Researchers using Law Mind's historical corpus should watch for variant spellings and Latin-English code-switching: sources may say "actio commodati," "commodati actio," "action of loan," or simply "commodatum action" interchangeably. Burrill explicitly cross-references *Commodati actio*, confirming these are treated as equivalent entries in historical dictionaries.
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Historical Dictionary Support
Both Black's and Burrill's confirm the civil law origin without disagreement, though their entries differ in depth. Black's situates the action within a broader family of obligations, noting it "included several actions appropriate to enforce the obligations of a borrower or a lender" and citing Hunter's *Roman Law* as authority — a rare and useful citation that points researchers toward the treatise literature for substantive development. Burrill's entry is sparse ("an action of loan") and cross-references the inverted form *Commodati actio*, which is the more natural Latin word order and the form more commonly used in the Roman sources themselves.
Neither historical dictionary develops the directa/contraria distinction explicitly, nor do they engage with the good faith (*bona fides*) dimensions of the action that Roman jurists treated as central. Researchers seeking doctrine should go beyond these dictionary entries to the Roman law treatise tradition — Hunter's *Roman Law*, Gaius's *Institutes*, and Justinian's *Digest* (particularly D. 13.6) — rather than relying on the dictionary summaries as substantive expositions.
The absence of discussion in historical dictionaries of the *contraria* form is a gap worth flagging: it can create a false impression that the actio commodati ran only in one direction.
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Jurisdictional Note
The actio commodati as a formal action belongs to Roman law and has no direct procedural equivalent in common law jurisdictions. In civil law systems influenced by Roman law — Louisiana, Quebec, and civilian European systems — the conceptual structure of *commodatum* and its associated remedies survives in modern civil codes, though the Latin terminology is generally replaced by vernacular statutory language.
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