In the Roman law there were many kinds of agreements and contracts which could be used to bind sides. There were real, consensual, literal and verbal contracts. Among the verbal contracts, which were carried out by saying strictly defined words in strictly defined situations, there was a promise of a dowry (dotis dictio) and freedmen’s oath (iusiurandum liberti) but the most important was the stipulatio.
Stipulatio in the Roman law
It was one of the oldest types of contracts in the Roman law, dated to as early as before the Law of the Twelve Tables. Stipulatio was a promise to carry out a beneficiary action by the debtor for the creditor and therefore it was a type of contract binding only one side. Originally, only a specified sum of money could be the object of the stipulatio but with time the range was broadened to include a list of specific things (certa res) and finally also benefits such as actions or refraining from action. According to the rule alteri stipulari nemo potest it was prohibited to engage in contracts on behalf of a third party, however this rule did not include slaves and persons alieni iuris.
Stipulatio was popular among the Romans because of a wide range of cases in which it could be used, as opposed to narrowly defined ranges in case of the other types of contracts. Another advantage was that, as opposed to the informal contracts and contracts without any legal protection (pacta nuda), it was suable as a formal contract.
The sides of the stipulatio were stipulator (the one accepting the promise) and promissor (the promising one). Apart from these two traditional participants the contract could include further parties – it could be extended to co-debtors, solidary co-owners, side-creditors (adstipulator), debt guarantors (adpromissor) and solutionis causa adiectus (usually a banker entitled to accept a benefit from the debtor but not entitled to cancel the contract and vindicate the receivables through litigation). Side-creditors were usually appointed in order to get around the prohibition of the post mortem stipulatio, they were personally entitled to accept a benefit, vindicate through litigation as well as release the debtor and they answered before the main creditors for any damage.
Stipulatio allowed for almost any commitment, also based on more than one stipulatio (for example in the case of sale and purchase agreement there were two stipulatios necessary – an obligation to pay the agreed price and an obligation to issue the specified thing). It could also be used to replace one obligation with another (aquilian stipulatio), appoint a guarantor, side-creditors, co-debtors and also to create side obligations (interest on a debt, contractual penalties). Stipulatios could be created while on deathbed but created mortis causa (in case of death) were invalid.
The form of stipulatio was a series of questions and answers from both sides of the contract present in the same place at the same time. The oldest were the questions concerning the promise (Dari spondes? – Do you swear? Spondeo – I swear) available only to the citizens. With time more expressions became available (Promittis? – Do you promise? Promitto – I promise, Dabisne? – Will you give? Dabo – I will give) and even Greek language was approved for use in this type of contract, as regulated by the emperor Leon I in his constitution from the year 472.
The obligation created through stipulatio could be abstract (stipulatio sine causa) or specific (causal stipulatio), created because of a specific cause, although the cause did not have to be revealed in the text of the contract – in the case of cautio discrete the cause was revealed while in the case of cautio indiscrete it was not. Because of its form stipulatio was convenient for the creditor as it allowed to create an obligation without a counter-obligation.
In terms of legal protection there were several actions available for the sides of such a contract. The creditor could vindicate in many ways. During the period of the legis actiones he could invoke Lex Silia, if the stipulatio involved money, or Lex Calpurnia in other cases. Later, in the formulary system, he could use condictio certae creditae pecuniae, if the contract involved money, actio ex stipulatu certi for other specified things (later condictio certae rei) and actio ex stipulatu incerti, if an unspecified thing or action was promised (actio ex stipulatu in Justinian’s law).
Also the debtor had a lot of possibilities to defend. Praetor could issue exceptio doli (charge of deception) to the debtor, the debtor could also invoke exceptio non numeratae pecuniae (sum no issued – the debtor did not receive money despite the binding loan contract) or charge the creditor with querela non numeratae pecuniae (lack of the legal grounds for stipulatio) – the use of the last two measures were limited by emperor Justinian to two years since entering of a stipulatio, if there was a cautio existing. It was Justinian who gave stipulatio its final shape, de facto making it a causal obligation.