I CONTRACTS FORMAL AND INFORMAL
Contracts in Roman law can be divided into two main categories. formal and informal. First. there was the formal contract of stipulatio. which was made orally.
not in writing. It was concluded by question and answer. which had to be in formal terms and had to correspond with one another. The promisee (or stipulator) would ask. for example. ‘do you promise to pay 1,000 sesterces?'. and the promisor must reply ‘I promise to pay 1,000 sesterces.' The exact correspondence between question and answer created an obligation binding on the promisor; but. if the two did not correspond exactly. no obligation came into being. There is much to be said for this insistence on exact correspondence. since it leaves it absolutely clear which verbal exchanges create binding obligations and which do not. The high classical jurists tolerated no discrepancy between question and answer; later this came to be watered down. so that a request for 1,000 sesterces and a promise for 500 sesterces might be held good for the lesser amount. on the basis that the lesser was included within the greater.So long as there was the necessary formal correspondence of question and answer. there was no restriction on the possible content of the promise — apart from the fact that an illegal or immoral promise' would be unenforceable. Stipulatio could therefore be used to give legal force to an agreement of any kind. It was a formal contract but an extremely flexible one. It was also a contract stricti iuris: its terms were interpreted strictly.
The second type of contract was precisely the opposite: entirely free of form. But each kind was applicable in only one specific situation. Contracts of this sort fall into various sub-categories, but for present purposes it is enough to say that some came into being when an object was delivered (contracts re: deposit, loan, pledge) and others came into being by agreement (consensual contracts: sale, hire, mandate, partnership).
In neither case was there any need for any set form. But the enforceability of the contract depended on its meeting the precise legal definition for that particular contract. If it did not, there was no contract.The difference between these two types of contract is fundamental. In the stipulatio a promise or series of promises was made, specifically adapted to the contractual situation at which the parties aimed. In consensual contracts, the law already set out the essentials which applied to a contract. So, for example, the consensual contract of sale (emptio venditio) included implied warranties on the part of the seller about his title to the goods and about their quality. In a sale by stipulatio such matters would need to be provided for expressly if they were to be terms of the contract.
On the other hand, in mutuum, the real contract of loan of money (or other measurable commodities), the contract was formed purely by the delivery of the money. But that was in some respects unsatisfactory: the contract of mutuum as such made no provision for the date for repayment of the loan; nor did it say anything about the payment of interest. If those were to be terms of the contract, they needed to be introduced by stipulatio.
These examples confirm the vital importance of stipulatio, both for concluding non-standard contracts and for adding non-standard terms to standard contracts.
In classical law it was therefore characteristic of the law of informal contracts that each contract had its own name; situations which fell outside the recognized categories were simply not contracts. Clearly, this leaves a wide range of cases. The most obvious is perhaps barter: one of the essentials of the contract of sale (as we shall see in the next section) was that the price should be in money. An exchange of goods for goods, barter, was therefore not a sale, and for most of classical law it was not a contract at all.
But towards the end of the classical period there are signs of an extension of the law of contract to cover even these anoma-19 lous situations, and there is the development of a category of so-called ‘innominate' (literally, ‘nameless') contracts. These covered arrangements for exchange of goods or services. If we ask why this development took place precisely in the late classical period, we are confronted with a choice familiar from chapter 2: on the one hand, it is arguable that this was a purely technical legal development, a change which the jurists regarded as desirable, having formed the view that the law of contracts had hitherto been too restricted in its scope; on the other hand, it might be thought that this was a reflection of some social change, and that social agreements which had hitherto worked perfectly well on an informal basis now came to be regarded as needing legal recognition and sanction. Which of these is more probable it is, as usual, impossible with any certainty to say.