Mahoney v. Grainger, 283 Mass. 189, 186 N.E. 86 (Mass. 1933)
Mahoney v. Grainger is a cornerstone case in the law of wills and estates for understanding how courts treat ambiguity and the admissibility of extrinsic evidence to interpret testamentary language.
When a will's residuary clause leaves property to "my heirs at law" and, applying that technical term, a single heir is ascertainable, may a court admit extrinsic evidence of the testatrix's contrary intent (e.g., to benefit first cousins) to vary the clear language of the will on the theory of latent ambiguity or mistake?
In construing wills, words are given their ordinary or, if applicable, technical legal meaning unless the instrument indicates a different intent. Extrinsic evidence is inadmissible to vary or contradict the unambiguous language of a will. Such evidence may be consulted only to resolve a genuine ambiguity—patent on the face of the instrument or latent arising upon application of the language to external facts—or to identify persons or property described where more than one subject fits the description. Absent statutory authority, a court will not reform a will to correct a scrivener's mistake or otherwise conform the instrument to an unexpressed intent.
No extrinsic evidence was admissible because the will was unambiguous. The phrase "heirs at law" has a fixed legal meaning and, applied to the facts, identified the testatrix's sole surviving aunt as the only heir at law. The aunt took the residuary estate; the first cousins took nothing under the residuary clause.
Mahoney v. Grainger is a leading authority for three propositions central to wills doctrine: (1) technical terms in wills are presumed to be used in their legal sense; (2) extrinsic evidence is inadmissible to contradict or vary unambiguous testamentary language and is permitted only to resolve genuine patent or latent ambiguity; and (3) courts will not reform wills to correct scrivener's errors absent statutory authorization. The case highlights the sharp line between a testator's subjective intent and the objective manifestation of intent in the executed instrument. It also serves as a drafting caution: if a testator intends to benefit "first cousins" or "next of kin," those words should be used instead of the technical term "heirs at law." Law students study Mahoney to master the ambiguity framework, to appreciate the policy tradeoffs favoring certainty and administrability over individualized intent, and to contrast traditional no-reformation rules with modern reforms in some jurisdictions that now allow reformation for mistake upon clear and convincing evidence.