The Saltonstall v. Saltonstall, 1927 case involved a dispute over the interpretation of a will and trust agreement. The testator had left his estate to his children in equal shares but also provided that if any child died without issue, their share would go to the surviving siblings or their descendants. One of the daughters passed away unmarried and childless, leading to disagreement among her siblings about how her portion should be distributed - whether it should be divided equally amongst them or according to seniority as per Massachusetts law at that time which favored elder sons in inheritance matters. The Supreme Court ruled that under the terms of this particular will and trust agreement, when one beneficiary dies without issue (children), their share is not automatically redistributed among other beneficiaries based on age or gender but rather equally as originally intended by the testator. This ruling clarified an important point regarding testamentary intent: unless explicitly stated otherwise in legal documents like wills or trusts, courts generally interpret provisions favoring equality among beneficiaries.

In the dissenting opinion for Saltonstall et al. v. Saltonstall et al., Trustee, Justice Holmes argued that the majority's decision to allow a trust beneficiary to challenge an amendment made by another beneficiary was incorrect. He contended that under Massachusetts law, which governed this case, beneficiaries could not alter trusts in ways that would harm other beneficiaries' interests without their consent. In his view, one of the main purposes of trusts is to protect property from being divided among numerous individuals and thus becoming unmanageable or less valuable; allowing beneficiaries to change them at will undermines this purpose. Furthermore, he believed it was inappropriate for courts to intervene in private arrangements like these unless there were clear indications of fraud or mistake involved - neither of which were present here according to him.