Mutuum

In Roman law, contracts could be divided between those in re, those that were consensual, and those that were innominate contracts in Roman law. Although Gaius only identifies a single type of contract in re, it is commonly thought that there were four, as Justinian identifies: mutuum (loan for consumption), commodatum (loan for use), depositum (deposit) and pignus (pledge).

Each varied about the expected standards of care, transfer of ownership, and other practicalities stemming from the purpose of each. They all involved the delivery or a physical thing, which is a defining characteristic. They were generally supplemented by the stipulatio and inominate contract, which allowed additional provisions such as interests to be added to contracts in re making them more suitable for commercial applications.

Justinian identifies four types of real contract – contracts in re (in a thing) – mutuum, commodatum, depositum and pignus. Common to all four was an agreement, and the delivery of a res corporalis. They are in contrast to consensual and inominate contracts. Real contracts were of limited significance, although they are featured prominently in the works of jurists. If a stipulatio had to be created to cover any interest, then it could be used to cover the other elements of the transaction as well.

Gaius, however, only mentions one type of contract in re: mutuum. The others certainly existed in Gaius' time. The other three can be distinguished insofar as they are different from traditional concepts of debt from which real contracts developed, are bilateral, do not transfer ownership, are bona fide and praetorian in nature. Gaius can therefore be seen as writing at a developing time in the law, although why the others are not mentioned at all in the Institutes of Gaius is not known.

A mutuum was a loan for consumption. It was the oldest contract in re, growing in importance after 326 BC when the lex Poetalia was passed. It could be used by people without the right of commercium – a package of rights to participate in the ius civile and to undertake remedies. It involved the delivery of certain types of fungible goods, such as money, food, and drink. Ownership was transferred, as was possession. In a strict sense then, because ownership passed, it should not be considered a loan. The mutuum obliged the borrower not to return the thing itself, because its use would involve consumption, but a similar thing in quantity, quality and size.

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