was made manifest by the unchanging laws of nature, which predisposed man to make promises. These views, originally pagan in nature, became fused with Christian theology in a way which provided a further justification for the morality of promising. Two important theological sources furnished the required material for such a process: Scripture and the canon law.

Scripture  There is a large repository of promissory textual material in the Bible, and both theological and legal discussion of biblical promissory ideas has not been insignificant.

Quite apart from an approach that promises derive their moral force from being virtuous acts mandated by the natural law (which, in the Christian tradition, is ultimately an expression of the divine law), another strand in the theological understanding of the moral value of promises considers promises as human reflections of divine acts of promising. This approach posits that, in so far as human promising borrows its nature and form from divine promising, it also takes its moral force from the divine source of promising. Clearly, whether or not one adheres to this view is dependent in large part upon a personal belief in the divine, but regardless of such personal belief or lack of it, it is undeniable that biblical conceptions of promise and of the importance of adherence to promises have been influential in the development of Western promissory philosophy. The writings of Aquinas, Scotus, the Spanish scholastics, and the Northern natural law school on the subject of promises are littered with biblical references. In Scotland for instance, Stair, when discussing whether natural law mandated the keeping of promises or gratuitous contracts, rejected the view of Connanus that it did not; in asserting the contrary, Stair stated that ‘especially this is confirmed by the law of God’, which he illustrated by citing from both Old and New Testaments.53

There are in both Old and New Testaments references to promise in relation to promises made by God, those made by human beings, and also frequent references to the ‘Covenant’ between God and his people, a covenant which can be described in promissory terms.54 References to divine promises abound in both Old and New Testaments. In the Old

53He cites Prov. 6:1, Neh. 9:8, and Heb. 10:23.

54There has been much debate among scholars as to whether biblical covenant references are best seen as referring to unilateral promises made by God, or to bilateral contracts entered into between God and his people (contractual promises), though the detail of such debate cannot be considered here.

Testament, divine promises are made both to the community55 as well as to individuals,56 a pattern repeated in the New Testament. Divine promises are seen as everlasting and unshakeable, an important template for the theory of the sanctity and irrevocability of promises in the human sphere.57 On the other hand, the references to promises made by humans in the Bible are less felicitous58 as well as less numerous; more often humans are seen making vows or oaths, rather than ordinary promises to their fellow men. There is a difficult passage from the Letter of James, which has on occasion been argued as forbidding human beings from making promises at all: James appears to say that human plans about the future are arrogant because ‘you know not what shall be on the morrow’.59 However, the view of later scholars, including Aquinas,60 was to the effect that the passage did not forbid promising outright, so long as those making them appreciated that all human plans are subject to God’s will.

Promising is a central feature of the biblical narrative, and indeed in the later reformed theological tradition it has been argued by some to be the central theme of the Bible.61 The biblical references to promise provided a fertile source of promissory material for the development of promissory and contractual doctrine in Western legal systems. That source material stressed the divine importance accorded to adhering to promises, as well as their inherently moral nature (given that God is portrayed as making promises), and thus proved useful for developing a theory of voluntary obligations which required adherence to that which was promised. Biblical sources were not relied upon as the sole justification for the moral force of promises, but, as in the writings of Aquinas, as one aspect of the argument deployed in defending particular views. The Reformation increased the direct usage of biblical source material in support of legal arguments, for, while in the pre-Reformation period, it was the canon law which was the paramount source in the development of the enforceability of promises, in Protestant countries at least the reference to canonical materials fell away after the onset of the Reformation, when the canon law came to

60Aquinas explains why these verses from James should not be seen as prohibiting a promise of a future marriage: Summa Theologica, Supplement, Q. 43.

61The reformed strand of theology dubbed ‘epangelicalism’ (from the Greek root, epengel-, meaning promise) characterises the fundamental theme of all Christian history as being the fulfilment of the divine promises made to man: see Kaiser, ‘The Old Promise and the New Covenant’.

be viewed with suspicion given its papal source. A good example of this change is seen in the writing of Grotius, who in his chapter on promises in De jure belli ac pacis includes a number of references to Scripture, but none to canon law.62

The canon law  The contribution of the canon law (by which is meant primarily the canon law of the Western, Roman Church) to the development of the idea of the inherently moral nature of promises, and in the importance of enforcing such promises, began to diminish with the Protestant Reformation of the late fifteenth and sixteenth centuries and was certainly over by the end of the eighteenth century. By then, however, that important contribution had transformed the idea of promise from a purely moral one to one which had become embedded, to varying degrees, in the private law of the various European legal systems, as will be seen from later discussion. The influence of the canon law on private law was more or less direct, and more or less profound, in different jurisdictions for various historical reasons which are referred to below.

The depositories of the canon law are numerous, the two most important from the medieval period being:

(1)the Decretum, a series of extracts from Scripture, the Church Fathers, and the various Councils of the Church. The Decretum was compiled between around 1130 and 1140 by Gratian, a canon lawyer and professor at the University of Bologna. Added to the margins of the Decretum is a gloss written by Johannes Teutonicus (who died in 1252), a Master General of the Dominican Order, supplemented by Bartholomew of Brescia (who died in 1258). The Decretum falls into three parts: the Ministeria, being general norms of canon law together with a tract on ecclesiastical persons and their functions; the Negotia, taking the form of questions and answers relating to administrative matters and the law of marriage; and lastly, De Consecratione, comprising maxims and canons on sacramental matters; and

(2)the Decretals, a collection of papal laws, compiled at the request of Pope Gregory IX by St Raymond of Penafort between 1230 and 1234.

62Grotius cites various scriptural passages referring to God’s promises, stating that ‘God Himself, who cannot be bound by any established law, would act contrary to His nature if he did not make good His promises’ (II.xi.4,1). Another example of the new Protestant attitude is found in the Scottish jurist Sir John Skene, who chose to annotate his 1609 reprint of Regiam Majestatem with a concordance including not canon law sources but biblical texts: see Cairns, ‘Ius Civile in Scotland’, 169.

Again the margin of the text as we have it today was supplemented by a gloss written by the canonist Bernard of Parma (who died around 1263), which incorporates references to, among other sources, the subsequent Code of Pope Boniface VIII commonly called the Liber Sextus.

These two collections, together with a number of other works, are collectively­ referred to as the Corpus Iuris Canonici.63

The Decretum and Decretals contain a number of texts relating to promise which were influential in the development of promissory ideas in private law. Thus, from the Decretum, the following texts among others exerted an influence on jurists of the time and later periods:

(1)D. 23 c. 6: The maxim that ‘[t]he breaking of promises is more to be feared than the breaking of general vows’;64

(2)C. 22 q. 2 c.14: A passage in which St Augustine,65 following Cicero,66 says that one need not keep a promise to return a sword to a person who has become insane (as mentioned earlier, Plato had used a similar example). A gloss to this passage explained that ‘this condition is always understood: if matters remain in the same state’.67 The Italian jurist Baldus de Ubaldis read this condition concerning promises into the civil law, holding that all promises were subject to it. The rule thus established is still known in the civil law as that of clausula rebus sic habentibus, or, as Common lawyers will more readily recognise it, as the doctrine of frustration or failure of basis. The rule is clearly an inroad in to the sanctity of promises, and so requires some justification, whether that of the civilian justification of an implied condition (justified therefore by reference to the tacit agreement of the parties) or that of equity (as in the Common law).

(3)C. 22. q. 5 c. 12: The maxim that ‘[t]here ought to be no falsehood in our words’,68 a maxim supported by the text from St Matthew’s Gospel ‘let your speech be yea, yea: no, no: and that which is over and above these, is of evil’.69 The maxim bears a striking resemblance

63A reprinted edition of the Latin text of the Corpus Iuris Canonici was published in two volumes in 2000.

64Solet enim plus timeri quod singulariter pollicetur quam quodgenerali sponsione concluditur.

67The gloss is that of Johannes Teutonicus, gl. Furens, ad. C. 22 q. 2, c. 14.

68ita quoque in verbis nostris nullum debet esse mendacium. The maxim is included with a reference to Wis. 1:11 and Prov. 14:5.

69Matt. 5:37: sit autem sermo vester est est non non quod autem his abundantius est a malo est.

to a passage of Aquinas quoted earlier,70 as well as demonstrating a continuity with the classical Greek thinking noted earlier concerning the importance of truth-telling. Helmholz has said of the significance of this passage for the development of the law that ‘[t]his ethical principle … furnished the first principle upon which the canon law of contracts was constructed. The hands of the canonists fashioned it into an instrument capable of enforcing promises of virtually unlimited character’.71 The maxim was a central plank in juristic development of the doctrine of promissory liability.

From the Decretals, further significant texts are worthy of note:

(1)A number of texts deal with the jurisdiction of the ecclesiastical courts in respect of promises, some founding, others excluding, such jurisdiction. Thus we have both a gloss on Sext 2.2.3 noting that ordinary contracts between laymen for commercial purposes do not fall within ecclesiastical jurisdiction,72 as well as Sext 2.11.2 stating that only promises conjoined with an oath give jurisdiction to the ecclesiastical courts. This jurisdiction over promises backed by oath was to be profoundly influential in developing the role of promise in European legal systems. Oral promises could, with the simple addition of an oath when made, easily be litigated before church courts, an evident advantage over the secular law position in most jurisdictions, where formalities were required to validate promises. This fact explains the rise in promissory cases before the ecclesiastical courts during the medieval period,73 though this eventually led to conflicts with secular courts which in England, for instance, prompted a dramatic curtailment of ecclesiastical jurisdiction in promissory cases.74 By this point, however, the ecclesiastical jurisprudence had in any event begun to result in a greater willingness to enforce promises in the secular courts (a development discussed further in Chapter 3).

(2)Specific texts justified the universal enforcement of contracts, embedding the principle of pacta sunt servanda in canon law, and eventually,

72Glos. ord. on Sext 2.2.3: Ex tribus tenebatur: ex iure communi, ex pacto, et vinculo iuramenti; ex ultimo coram ecclesia convenitur.

73An interesting study of English and Spanish ecclesiastical causes concerning promises is Helmholz, ‘Contracts and the Canon Law’.

74At the end of the fifteenth century, the penalties provided for under the English statute of Praemunire (originally enacted to regulate appeals to Rome) were utilised to curtail commercial claims before the English ecclesiastical courts.

through such texts, in the civil law.75 The principle was only formulated in the precise words of the maxim by Pufendorf, but there is no doubt that the principle could itself already be identified in canonical texts, not just from the Corpus iuris canonici, but also, for instance, in the writing of Hostiensis, Cardinal-bishop of Ostia in the thirteenth century, who in his published works made an important contribution to the idea of universal contractual enforcement. 76

Further canonical texts relevant to promise and contract which were to have an influence on secular law included texts relating to, amongst other matters, the just price (pretium iustum) of a contract, error (enunciated in a canonical setting largely in relation to marriage), specific performance, and rescission of contract for breach.77

As noted earlier, the pattern of influence of the canon law on the civil law differed according to jurisdiction. In England, the influence was felt largely in remedies which came to be granted in equity in the Courts of Chancery. This itself was a feature of the fact that most Chancellors who held office before St Thomas More were churchmen, and many equity drafters also had experience as ecclesiastical lawyers or were at least familiar with ecclesiastical forms of action. Many of the maxims which found their way into equity show a marked resemblance to those of the Liber Sextus. The totality of this effect might be described as an ‘indirect reception’ of canon law into the equitable jurisdiction of England.78 By contrast, the influence of the canon law’s position relating to promises in Scotland has been described as ‘positive and direct’,79 a conservative approach to legal change resulting in the pre-Reformation ecclesiastical jurisdiction over promises (which, as in England, had been extensive, but had also, unlike in England, suffered no pre-Reformation restriction),80

75Gregor. IX, Lib. 1 Tit. XXXV De Pactis cap. 1 (Pacta quantumcunque nuda servanda sunt): ‘Dixerunt universi: Pax servetur, pacta custodiantur’ (‘all said: peace should be ­preserved, pacts respected’); and cap. 3 (Iudex debet studiose agere, ut promissa adimpleantur): ‘Studiose agendum est, ut ea, quae promittuntur, opere compleantur’ (‘one ought to conduct oneself with care, so that, that which is promised will be achieved’).

76See Hostiensis, Summa aurea and Lectura. A very thorough analysis of the meaning, origins, and influence of the maxim is provided in Hyland, ‘Pacta Sunt Servanda: A Meditation’.

77For the influence of the canon law on some such areas in the Common law, see MartinezTorron, Anglo-American Law and Canon Law, pp. 136–42.

78See Martínez-Torrón, ibid.; Vinogradoff, ‘Reason and Conscience’, p. 198.

79Sellar, ‘Promise’, p. 266.

80The legal historian Gordon Donaldson, having examined the records of the Court of the Official Principal of St Andrews (an ecclesiastical court) from the sixteenth century, has