was the basic form of contract in Roman law. It was made in the format of question and answer.
Capacity In order for a contract to be valid, parties must have capacity: both intellectus ("understanding") and voluntas ("wish", "will"). Lunatics and infants lacked intellectus, and could not fully understand a legally-binding contract, or understand it, and therefore could not legally agree to one.G.3.106 Slaves lacked voluntas and therefore could not contract. Although slaves could not be bound by a contract, they could contract to benefit their master, even without his permission, (because he would then be able to choose whether or not to enforce itD.45.1.62) or with his consent, might burden him, because he would provide the necessary voluntas. Wards and women could stipulate under their tutor's authority,G.3.107 and this was not needed if they benefited under the stipulation.G.3.108
Intention to be bound The orthodox argument is that intention was not an essential condition of Roman contract law, but an integral Byzantium interpolation. However, David Ibbetson, a British legal academic specializing in Roman law, has argued that the intention of a contracting party was necessary. D.50.27.48 argues that, in the context of divorce, what was said in anger would not bind unless it was accompanied by action, e.g. a wife saying she will walk out and then doing so. A madman could not stipulate because he lacked understanding.G.106 These texts combined suggest that some form of intention to be bound was required.
Agreement Agreement was essential to a valid contract under Roman law. Without a meeting of the minds, the contract was void.D.2.14.1.3 The result of this was that animus was needed from both parties, both in order to accept the burden and in order to accept the benefit of the contract. The texts cover two situations where agreement fails.
Firstly, if someone stipulates for slave A and there are two slaves called A, which slave the stipulation is binding for depends on evidence extraneous to the verbal contract, for example, a hand is placed on the slave.D.34.5.21.pr.
Secondly, where a document has been used as evidence of a contract, but the document is ambiguous (which is where agreement is most important) the texts discuss two possible responses. This ambiguity may be resolved against the stipulator (the approach taken by Celsus and Ulpian), or the mistake may make the contract void (the approach taken by Venellius and Paul and followed in Justinian’s institutes).
Orality A Roman contract had to be oral. Since the contract was oral, it could not be made by the deaf or dumb without a slave to act as their mouth or ear piece and could not be made from afar. D.45.1.1.pr, which appears to have been compressed, since the reasoning does not follow perfectly, says that there can only be a stipulation when parties speak, so the mute, deaf and dumb cannot stipulate, and someone who is not present cannot stipulate. However, a slave may stipulate for a deaf or dumb master.
The Greeks, however, used purely written contracts, which clearly had some influence on Roman law, which did use writing. However, authors such as Zimmermann and Nicholas held that the oral contract remained crucial, and the documents merely supplemented the contract as evidence. In C.4.32.1circa 160AD a question was sent to the emperor about a situation where a document witnesses a promise to pay back a loan but does not mention the requirement of interest, which was a part of the oral promise. The response is that the interest is still enforceable. This fits with D.50.17.92, which says a stipulation which is recorded wrongly is still valid. Also, D.2.14.7.12 is an example of a written stipulation, and it speaks in the past tense, that T had asked and M had promised, which again suggests that the written documents performed an evidential function. More often than not, by the Late Empire under Emperor Leo (which influenced his rescript), the oral stipulation was never in fact made; the documents recorded a non-event.
There is some dispute about whether or not the stipulatio degenerated and became a written contract. Barry Nicholas has argued that circa 140AD a written document became very strong evidence of an oral agreement,D.45.2.11.1. creating a presumption that an oral promise had been made, unless it could be proven that the parties had not met. By 201AD this is stated explicitly in the texts.for example, in S.7.2. This approach demonstrates an attempt by Roman lawyers to reconcile Greek contracts, which must be in writing with the Roman world, which required an oral exchange.
Diosidi has argued that the stipulatio degenerated further, so far that although theoretically an oral exchange is required, in practice this was not necessary. The first text he uses to support his argument is G.3.1.34circa 130AD. However, this text refers to chinographs and synographs, (not Roman terms) and a better interpretation of it might be that it simply describes the situation in Greece. He also refers to D.45.1.30,circa 220 AD in which a written document purports to be a contract, however this is not incompatible with the arguments of Nicholas.
Specific words G.3.92 says that to create a verbal obligation pairs of words should be used, with a correspondence between question and answer. It then uses the Latin word spondeo, lists six examples, and then says that only Roman citizens could use the verb spondeo. C.8.37.10, a text from the time of Justinian I, says that stipulations shall be enforced whatever words they are couched in. It is clear that there was some degeneration of the stipulatio, however, since the extent to which the stipulatio degenerated depended on the view taken as to what the stipulatio originally required.
Nicholas has argued that veluti here means "that is to say" and that the stipulation began as a set list of words that could be used. There are examples in the texts of other words being used but he argues that most of these are interpolations.for example D.19.2.54.pr (which is generally accepted as being interpolated) and D.45.1.38.24 which appears to have been torn from its original context as it is inelegant and formed in bad grammar. He accepts that some words may have been added to the list such as Inst 3.1. and argues that Justinian was attempting to revive classical law but at the same time, reconcile written and oral practice, so he interprets this text to mean that the list becomes an unbounded list at this point.
Other academics have contested this. Watson argues that since you can destroy a stipulation without formal words, you can probably create one in the same fashion. Winkler says that Gaius always uses veluti to mean "for example". Van Oven points to the fact that G.3.92 does not say that the words create a stipulation but that they create a verbal obligation. He has argued that given that there are another two types of verbal obligations not in the list, the list in inconclusive. Also, it seems strange that a limited list should contain such informal words as dari, meaning simply "to give". (Of the six examples of words given, the first four are very formal, but the others are very common). This seems, at first glance, to be undesirable, as parties would be bound far too easily. However, Ibbetson has pointed to the requirement of intention and said that this means that an unbounded list was not a problem. Taking this approach, Riccobono thus argues that C.8.37.10 means that there was no longer any need for question and answer.
D.45.1.2 suggests that the degeneration may have gone further still, requiring no correspondence between question and answer. This text says that if one party says “Will you give?” and the other says “why not?” he is bound, but if he merely nods, there is no civil or natural obligation. The example of a guarantor is then given. The text is clearly abbreviated, and it seems unlikely that the stipulation did ever degenerate this far, as if this was the case, we would expect the many references to agreement between question and answer to have been excised from the other texts.
Languages The texts are inconclusive as to which languages can be used. G.3.93 says that stipulation is valid in Greek, providing the other party understands it. They may have only mentioned Greek, and no other language, simply because this was the only other language Romans spoke.
D.45.1.16 says that if the question is in Latin and the reply is in Greek, the obligation is settled, providing the two correspond. This seems to suggest that there was not a closed list of words. Importantly, it then goes on to say that other languages can only produce an obligation, not an action. However, the examples given are all in dead languages – which may be significant. An obligation is only produced when both parties understand each other, but this understanding may be reached through an interpreter. The last clause suggests that the text may have been interpolated, as the use of an interpreter seems unlikely, as it would be highly problematic because the interpreter might lie as to what was being said.
Conditions about the timing and interval No gap between question and answer D.45.1.137.pr considers whether or not there can be a gap between question and answer. It states that a moment may naturally intervene but otherwise it should be continuous, and “he” may not begin something else, even if the reply is given on the same day. The point of the text seems to be that the question and answer must be glued together, but there are a few uncertainties. The first part, referring to the intervention of a moment, may be an interpolation, however, it may be a careful qualification by a lawyerand is supported by D.45.1.1.1 which suggests there may be a brief gap and the party may even go away and then come back again. Who it is that may not begin something else is also unclear -- the Latin is ambiguous -- but it seems likely this text is referring to the actions of the promisor.
That the text expressly rebuts the idea that a reply may be given on the same day after a party has undertaken some other business, suggests that such things were valid at some point in Roman law, although it could be an interpolation. D.45.1.1.1 says that a person answering on the same day is bound but someone answering on the next day is not. An analogy may be drawn with a legal trial, where things had to take place in one day but they would divide the day, so it was technically the same day, even though not chronologically. The emphasis placed was on factual continuity and legal bondedness.
Superfluous words between question and answer It seems that any superfluous things between question and answer may have been simply ignored; this is certainly the approach taken in D.45.1.65. However, the author of this text was Florentinus, which is interesting. There were two persons of this name, and one of them was a contemporary of Ulpian. Generally the Digest tends to quote Ulpian, so we would expect Ulpian to have been quoted. The other Florentinus came after Ulpian, which would suggest that, if Ulpian did not say so, this was only true in later law. However, this is uncertain as the thought may simply have seemed too obvious for Ulpian to have pointed it out.
Correspondence of subject matter If something was described differently between the question and answer, for example, if a pen was referred to as a writing instrument in the answer, the stipulation was still valid. D.45.1.136.pr
Content of the contract Conditional question and unconditional answers to conditional questions were invalid in Roman law.D.45.1.1.3
Stipulation for when I die was considered valid and was taken to mean "I will perform when I am dying", i.e. performance is due in the last moments of life.G.3.100 However, a stipulation for the day before death was not valid.Inst 3.19.15