Whether Mrs. Mitchill could enforce the Laths' oral promise to remove the ice house despite the parties' detailed written land-sale contract.
Holding
No. The oral promise was inadmissible under the parol evidence rule because it was too closely connected to the written sale transaction to qualify as an enforceable collateral agreement.
Reasoning
The parol evidence rule is not merely a rule governing the admission of testimony. It defines the boundaries of the parties' contract: when a writing is intended as the final expression of their agreement, an earlier or contemporaneous oral term cannot alter or add to that agreement. The rule does not bar a genuinely separate and independent collateral contract, but separating such a contract from an impermissible oral addition requires attention to substance rather than labels.
Judge Andrews stated that an oral agreement may supplement a written contract only when three conditions are met: it must be collateral in form; it must not contradict an express or implied provision of the writing; and it must concern a matter that parties would not ordinarily be expected to include in the writing. Put differently, the asserted oral term cannot be so closely tied to the principal transaction that it is naturally part and parcel of the written agreement.
The ice-house promise was collateral in form, because it concerned removal of a structure from land other than the farm being conveyed. But the written agreement was a detailed and apparently complete account of the parties' reciprocal obligations in the farm sale. It specified not only price and conveyance, but also numerous ancillary matters, making it natural to expect an inducing promise concerning an objectionable nearby ice house to appear in the same writing.
The surrounding circumstances did not change that conclusion. Knowledge that the ice house existed and that Mrs. Mitchill disliked it would not itself cause a reader to infer a separate agreement about its removal. If the Laths had truly undertaken that obligation as consideration for the purchase, the court thought it would ordinarily have been included in the written sale contract. Allowing proof of it would therefore undermine the policy of protecting integrated written agreements from asserted oral additions.