Steinfield v. Monadnock Mills

The so-called parol evidence rule, treating a writing which sets out an agreement of parties as their contract, though often spoken of and dealt with as a rule of evidence, is in reality one of substantive law. It determines “where and in what sources and materials are to be found the terms of a jural act.” 5 Wig. Ev., s. 2425. “When a jural act is embodied in a single memorial, all other utterances of the parties on that topic are legally immaterial for the purpose' of determining what are the terms of their act.” Ib. This is not because it is a writing, but because the parties intended to…