PROMESSA. – It is the cause of the obligatory relationship, unilateral or bilateral, produced by the will of one or more persons who freely and spontaneously bind themselves, in the ways and under the conditions permitted by natural or positive laws, to perform, gratuitously or upon the fulfilment of an agreed condition, any service whatsoever, or to refrain from doing anything, for the benefit of a third party. The overly frequent use of promises and their variety often make a perfect understanding of this institution difficult. It should immediately be noted that various other notions must also be kept in mind, whether wholly akin or merely connected, and principally matters concerning contracts (v. CONTRATTO), the difference between a promise and a resolution (v.), betrothal (v.), and also the particular nature of the obligatory force produced by the promise (v. FEDELTA).
The CIC refers, with regard to contracts, to the laws of the individual States (can. 1529); and contents itself with establishing rules for certain particular contracts, especially those concerning ecclesiastical property (cann. 1530–43); it therefore does not deal ex professo with the promise. The sole exception, apart from can. 1017, which regulates matrimonial promises very briefly, is constituted by can. 150 §§ 1–2, which establishes that a ecclesiastical office (v.) produces no legal effect.
A promise may constitute either a simple offer made to another, generally without an obligation in justice, or a genuine contract, according to the will of the promisor. 1) As a simple offer in favour of a third party, a promise must, by natural law, be completely spontaneous, not extravagant, gratuitous, known and not refused by the person to whom it is made. Spontaneity is required by the very nature of the promise which, in this case, having no counterpart constituting remuneration for it, cannot tolerate coercion of any kind. The only things to be regarded as lacking spontaneity are genuine physical or moral coercions, since advice or a desire expressed, even with a certain insistence, by outsiders or by the promisee himself does not have the effect of eliminating the substantial spontaneity necessary in a promise. Moreover, the promise must not be extravagant; that is, it must have a justification and remain within the limits of the social status to which the promisor belongs (in this regard it should be recalled that a completely extravagant promise has, since s. Alfonso, been considered by various theologians to be positively illicit and also invalid). Gratuitousness entails that on the part of the promisee (or of a third party on his behalf) there must be no performance constituting a genuine juridically discernible counterpart; acts of pure liberality on the part of the promisee are not, however, excluded. Finally, it must be known to the latter and not refused by him; for it is impossible to have precise obligations, other than those of a simple resolution (v.), towards someone who is unaware of what depends exclusively on another’s will, still less towards someone who possibly renounces the offer by a positive act. It is likewise a matter of natural law that every promise must in some way be useful to the promisee; for when every purpose, end and utility is lacking, the thing itself is lacking for the promisee; and therefore it is not enough that the promised thing be merely neither harmful nor dishonest. Again by natural law, a promise may concern either a personal performance or the performance consisting in a real thing distinct from a personal activity of the promisor. The obligation to keep a promise is one of fidelity alone and consequently, by its nature, a light one, since failure to perform entails only a lie (it is well known that the eighth commandment does not, in itself, bind except under venial sin). Nevertheless, in particular cases an obligation, even a grave one, of commutative justice may also arise; in such a case, however, not only the promisor’s precise intention in this regard is indispensable, but also, at least generally, a certain external solemnity, such as the presence of witnesses or a written form, together with some damage suffered by the other party in the event of failure to fulfil the promise. In any event, a promise not expressly converted into a genuine contract is never presumed to bind by a strict duty of justice—that is, with an obligation of restitution in the event of non-performance.
2) As a contract, a promise is the transfer of a right in favour of a third party who accepts it in order to obtain a corresponding performance. The transfer of the right in favour of the third party remains gratuitous even when made in return for a future or contemporaneous performance, not only because it is generally spontaneous in its formulation, but also because it is often not proportionate to that performance. Therefore, a promise, even if materially remunerated, must not be confused with a sale or an exchange. In a contractual promise, as in a simple one, particular account must be taken of the promisor’s will in order to judge the nature of the obligation arising from it; nevertheless, it is commonly admitted that strict duties of justice arise from it and, consequently, that the promisor is obliged to repair any damages resulting from failure to perform, while the promisee has the natural right to recover, compensation (v.), both the value of the unperformed obligation and the resulting damages. It should not be thought that this obligation is by its nature and always grave: this depends in part on the promisor’s will, especially insofar as it is known to the promisee, and always on the magnitude of the matter considered in the concrete circumstances.
Regarding the cessation of the obligation induced by a promise, apart from what is said concerning contracts in general, it must be held that a pure and simple promise, whether personal or real, ceases outright upon the occurrence of circumstances which, had they been foreseen, would have induced the promisor not to make it, and always upon the promisor’s death; a contractual promise, on the other hand, if real, passes to the heirs, who must satisfy it from the deceased’s estate. Both the promisor’s heirs and the promisee’s heirs must also discharge the obligation towards the latter’s heirs if the promisee predeceases the promisor and the promisor intended to benefit not the person of the promisee but his family.