In the spirit of Dutch antidisestablishmentarianism, or perhaps in the last kick of youthful rebellion, in 1992, Peter Tiersma published a lengthy law review article on speech acts and contracts (Tiersma 1992). Flouting the received wisdom of Christopher Columbus Langdell, of Karl Llewellyn, the Second Restatement of Contracts, and of legal realism more generally, he argued that there is a significant conceptual difference, and distinction to be made, between bilateral contracts and unilateral promises. Tiersma’s argument, in nuce, is that a promise is a unilateral commitment, in the language of the courts, a sacred pact, a solemn covenant, a binding avowal between the subject and their future, the divinity or nature as one wishes, that is independent of any other subject’s act or promise. A contract, by distinction, is from the Latin contraho, to draw together, and is a transitive process in which negotiations, offer, and acceptance lead eventually to a bilateral exchange of commitments and hence to contract formation, an exchange of promises. A proper grasp of this elegantly formulated and crucial distinction between bare promises and contracts, unilateral and bilateral, would spare the courts many errors of reasoning and on occasion legally perverse if not manifestly unjust results.
Lawyers, according to Martin Luther and many more modern divines, are fated upon their demise to an exceedingly rapid passage to Hell. It is perhaps for this reason, because of their secularism, that they seem to have been symptomatically uncomfortable in developing the doctrine of promising. The cases on unilateral contracts, which is to say bare promises, go back to Rogers v. Snow, and the promise to pay a man who walks from London to York to deliver a bond, but the more modern and variant discussions concern promises relating to climbing greasy flagpoles, walking across Brooklyn Bridge, or sending a tramp around the corner. Such de minimis examples tend to betray an evasion of the promissory basis of the commitment. There is no contract, no drawing together, no bilateral exchange, but rather, in good Christian terms, a promise, a commitment to perform if the conditions of the promise are met. As the unilateral promise is a commitment, a covenant with the divine or whatever other concept of higher power suits the illocutionary actor, it binds the promisor. That is the nature, the ontology, of the promise—it is an act of conscience, which according to the early legal authorities, means to “know with,” meaning here to know with God.1 If a promise is made, then it is breach of promise—laesio fidei in the ecclesiastical law—to retract or fail to perform. This is quite independent of any promise in return, and indeed in Christian doctrine it is precisely when it becomes unprofitable, when adverse circumstances challenge the promisor, that it is most necessary to keep the promise, to turn the other cheek. Such commitment is singly and solely the consequence of promising, the ontological entailment of the avowal that Saint Germain elaborates in Doctor and Student in terms consistent with the Roman law of causa: “And if the promise be good and with a cause though no worldly profit shall grow thereby to him that makes the promise but only a spiritual profit … it is most commonly held that an action … lies in law canon” (St. Germain, 1530/1974, 230).2 It is this action that the common law took over from the spiritual jurisdiction in the mode most recently of promissory estoppel or non-bargain promise, an equity that subsists not in bargain but precisely in the illocutionary force and commissive speech act, the unilateral commitment of the promisor.
The modern conflation of the unilateral and bilateral in the shadowy notion of bargain is, as Tiersma correctly points out, a source of error. The perambulator from London to York, the climber of the greasy flagpole, the tramp who hazards to cross the road, are neither making a promise nor performing a promissory act; rather, they are much more simply putting faith in the promise, and believing the promisor. Attempts to create a contract out of such faith are both misguided and confusing. There is no mutuality of obligation, there is no return promise, there is at most behavior that indicates belief in the veracity of the promisor. Thus, it is perfectly correct to allow an equitable remedy where one of our perambulators or climbers has believed the promisor and acted accordingly, only to be shunned by the latter. This is not because there is a contract but because there has been breach of promise. Occasionally, though with an exceptionally tortured logic, the courts come to such a conclusion, as in Cohen v. Cowles Media