Definition
A contract in Spanish civil law by which one person lends to another an object that is not consumable, doing so gratuitously, with the borrower obligated to return the same object in kind at a specified time. The lender retains ownership throughout; only possession and use pass to the borrower. No consideration or payment is exchanged — the loan is purely gratuitous. Commodato is the Spanish-law equivalent of the Roman and civil-law concept of commodatum.
Three elements define the contract: (1) the thing lent must be non-consumable — capable of being returned in its original form after use; (2) the loan must be gratuitous — any payment transforms the arrangement into a different contract; and (3) restitution of the identical object is required, not a substitute or equivalent value.
Common Confusion
COMMODATO / COMMODATUM: These are not separate concepts but parallel-language expressions of the same legal institution — commodato in Spanish law, commodatum in Roman and general civil law. Historical sources use them interchangeably, and Black's (both editions) explicitly equates them. Researchers working across civil-law jurisdictions should treat the terms as functionally identical and search under both headings.
COMMODATO / MUTUUM: Commodato is easily confused with mutuum, the civil-law loan of consumable goods (grain, money) in which ownership transfers and the borrower returns an equivalent quantity, not the original thing. The non-consumability requirement is the diagnostic distinction. A loan of wine is mutuum; a loan of a horse or a piece of furniture is commodato.
COMMODATO / DEPOSIT (DEPOSITUM): Both involve temporary transfer of possession without payment, but depositum is made primarily for the benefit of the depositor (who wishes the thing kept safe), while commodato benefits the borrower (who uses the thing). The direction of benefit matters for assigning liability under civil law.
Core Elements
Non-consumability of the object. The thing lent must survive use in its original form and identity. Tools, animals, vehicles, and furnishings are classic examples. Money, grain, or any fungible consumed by use cannot be the subject of commodato; such a loan falls under mutuum instead.
Gratuitousness. The loan carries no compensation. If the borrower pays for the use, the contract becomes locatio conductio (hire or lease) rather than commodato. The gratuitous character is essential to the doctrinal category, not merely a description of a common arrangement.
Restitution in kind. The borrower must return the specific object received, not its monetary value or an equivalent substitute. This distinguishes commodato from mutuum at the level of obligation and from sale or barter entirely.
Retention of ownership by the lender. Ownership never passes. The lender's rights against third parties who damage or take the thing are unaffected by the loan. The borrower holds the thing as a precarious possessor and bears responsibility for loss or damage attributable to misuse or negligence.
Why It Matters in Research
Commodato appears in legal sources connected to Spanish colonial law, Louisiana civil law, and other mixed civil-law jurisdictions in the Americas. Researchers working in Louisiana property law, Puerto Rican civil law, or historical Texas and California legal materials may encounter the term in instruments, judicial opinions, or treatises where it carries precise doctrinal weight — not merely a synonym for any informal loan arrangement.
The critical research trap is anachronism: common-law jurisdictions absorbed the underlying concept into the law of bailment, and modern American courts analyzing gratuitous loans of personal property typically apply bailment doctrine without reference to commodato at all. An opinion from a common-law state that would have been classified as commodato under Spanish law will appear in the sources under bailment or loan for use. Cross-referencing both doctrinal categories is essential when tracing a legal question across the civil/common-law divide.
Researchers using historical indexes should also search commodatum, as sources organized under Roman law headings often subsume the Spanish term without separate treatment. Bouvier references Ayliffe's Pandects and Brown's Civil Law for further depth — both are available in historical legal collections and provide the Roman-law scaffolding that Spanish law borrowed directly.
Historical Dictionary Support
The historical sources are in close agreement. Black's (both editions), Bouvier's, and Rapalje & Lawrence give substantially identical definitions, with minor variation in phrasing. All identify the Spanish-law context, the gratuitous character, the non-consumability requirement, and the obligation of restitution in kind. None departs from this core formulation.
Bouvier adds doctrinal texture absent from the others, noting (via Brown's Civil Law) that the property involved may be called "commodated property" — a term of art that signals the borrower's limited interest and the lender's continuing ownership. This framing reinforces the distinction from mutuum, where ownership does transfer.
What the historical dictionaries do not address is the treatment of commodato in post-colonial American jurisdictions or its displacement by bailment doctrine in mixed-law states. Researchers should not assume that the historical definition captures how courts in those jurisdictions actually applied the concept in practice.
Jurisdictional Note
Commodato as a formal doctrinal category survives most visibly in civil-law and mixed jurisdictions: Louisiana, Puerto Rico, and the civilian traditions of Latin American countries. In common-law states, courts analyzing the same fact pattern (gratuitous loan of a non-consumable object) apply bailment doctrine rather than commodato, producing functionally similar but doctrinally distinct results. The choice of framework can affect liability rules, so jurisdictional identification is a threshold issue in historical research involving this term.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Bailment (for the common-law analog and comparative treatment); Loan for Use (for the Roman and civil-law framework from which commodato derives).