Suppose A promises B that if B introduces to A someone who will conclude a contract for the purchase of A’s property for a price of at least £6.5m, A will pay B the specific sum of £1.2m. Suppose that this represents the extent of their oral agreement, that nothing material is written down, and that there are specific, idiosyncratic, reasons for picking out the particular sum of £1.2m. If a buyer is introduced, and contract duly concluded but only for £6m, there being no suggestion of dirty trickery1 on A’s part, where does that leave B? According to a majority of the Supreme Court in Barton v Morris,2 with the cold comfort of receiving what he contracted for, which was precisely nothing. The minority would have awarded a reasonable sum on the basis that the contract between A and B provided for it, one of them also considering that a claim on the basis of unjust enrichment would also have lain and would have led to the same outcome.

The case was not one liable to be disposed of by the painstaking analysis of decided cases, but asked more basic questions about the foundations of the common law of contract. Lord Burrows described the facts as “beautifully simple”, thereby locating beauty firmly in the eye of the beholder. The same cannot be said for the explanation, offered by the Supreme Court, of how the common law met the challenge which those simple facts disclosed. For the majority, Lady Rose expressed herself with unsparing directness. On the evidence recorded by the trial judge, the oral provision for payment was to be taken as the beginning and the end of the payment obligation of the contract: not just because it was, but because it had to be: “when parties stipulate in their contract the circumstances that must occur in order to impose a legal obligation on one party to pay, they necessarily exclude any obligation to pay in the absence of those circumstances”.3 That being so, it was as impossible in logic as it was in law to find that the contract accommodated, as an implied term, a supplementary payment provision which would require payment of a different sum to be made if the property were sold for less, because such a term would contradict the payment provision that the parties had expressed.