Innominate contracts

Originally, Roman jurists recognized as contracts only a restricted number of legal transactions. The expression “innominate contracts” refers to a group of transactions, primitively not contractual, which came into existence only after one of the parties performed his obligation.

Innominate contracts constituted a later development of the classical agreements in which the simple agreement itself had no binding force. Suppose that Titius agreed with Caius that he would give an amphora of wine in exchange for Caius’s amphora of oil. In early law, after giving his amphora of wine to Caius, Titius had no legal remedy to demand Caius’s amphora of oil. The only action that Titius could bring against Caius was the condictio (in some cases, the actio de dolo) in order to recover his amphora of wine, because his transfer had no legal ground (datio sine causa). Later, the praetor

The law of obligations: contracts 195 granted an action in factum to the party who had already performed his obligation to the other party in order to force the other party to carry out his part of the agreement. Justinian introduced an actio praescriptis verbis based in good faith to protect all kinds of bilateral contracts in which a party, after performing his obligation, claimed the performance of the reciprocal obligation by the other party.

Innominate contracts embraced the following types (Paul, D. 19.5.5pr.): do ut des (e.g., I will give you four loaves of bread so that you will give me a jar of vinegar); do ut facias (e.g., I will give you an amphora of oil so that you will teach me Greek for two days); facio ut des (e.g., I will heal your slave’s broken arm so that you will give me a toga); and facio ut facias (e.g., I will repair your roof so that you will keep my slave safe for a month).

Relevant innominate contracts were the permutatio, the aestimatum, and the precarium. A permutatio (barter) was the exchange of one thing for another. According to the Sabinians, barter should be considered a sale, and therefore a consensual contract, but the Proculeian doctrine prevailed that without a price there was no sale (Paul, D. 18.1.1.1.). According to Justinian, a barter was a real contract that demanded performance for one of the parties. An aestimatum was a transaction by means of which an owner transferred a thing to another person who had to either restore it or pay a fixed amount of money within a fixed term, while retaining any profit the recipient had obtained from selling it at a higher price. Finally, the precarium was a gratuitous grant of the use and enjoyment of a thing, revocable at will (Ulpian, D. 43.26.1pr.).