parol evidence rule v. plain meaning rule

Question

I saw this paragraph {"[a] clear conceptual division would treat the plain meaning rule as about interpreting the provisions of contracts, and the parol evidence rule as about establishing what count as the controlling terms of integrated contracts." } in a case (Burlison v. United States, 533 F.3d 419 (6th Cir. 2008)), and I know that parol evidence rule, but I could not understand the differences between parol evidence rule and plain meaning rule and this section is unclear for me.

Answer 1

The term "plain meaning rule" canonically applies to statutory interpretation. A paraphrase from this article by Baude & Doerfler is that

otherwise-relevant information about statutory meaning is forbidden when the statutory text is plain or unambiguous

which is similar to the parole evidence rule of contract law. A version of the rule can be found applied to contract law. In this article, the rule is expressed as saying that

the meaning of contractual language be determined solely by attaching the plain or usual meaning to words that appear clear and unambiguous on the face of an agreement.

That article discusses how the plain meaning rule is rejected by the UCC and the Restatement (Second) of Contracts, in other words, the rule is coughing up blood. Citing Hurst v. W.J. Lake & Co., 141 Or. 306 the "rule" has the effect that

words of the parties [are run] through a judicial sieve whose meshes [are] incapable of retaining anything but the common meaning of the words, and which permit[s] the meaning which the par-ties had placed upon them to run away as waste material.

This article by E. Posner discusses the relationship between the two rules, without stating what the plain meaning rule is, applied to contracts. To understand what Greenawalt specifically has in mind there, you'd have to search his book to say what he says about the rule. As he points out, many courts make no distinction between the two rules.