R2d § 209
Integrated Agreements
(1) An integrated agreement is a writing or writings constituting a final expression of one or more terms of an agreement. (2) Whether there is an integrated agreement is to be determined by the court as a question preliminary to determination of a question of interpretation or to application of the parol evidence rule. (3) Where the parties reduce an agreement to a writing which in view of its completeness and specificity reasonably appears to be a complete agreement, it is taken to be an integrated agreement unless it is established by other evidence that the writing did not constitute a final expression.
Professor's notes
Elements: (1) an integrated agreement is a writing constituting a final expression of one or more terms of an agreement; (2) whether there is an integrated agreement is determined by the court as a question preliminary to interpretation or application of the parol evidence rule; (3) a writing in apparently complete form is taken to be an integrated agreement absent contrary evidence.
Gianni v. R. Russel shows the classic four-corners approach.
UAW-GM v. KSL operationalizes the modern integration analysis with merger clauses.
Common misunderstanding: students think the writing's existence settles integration. § 209 leaves integration as a preliminary question of fact for the court: and (2) treats it as ANTECEDENT to the parol evidence rule. Merger clauses are strong but not conclusive; the court still asks whether the writing was meant as final.
Cases that operationalize this rule
Text
R2d § 209. Integrated Agreements.
(1) An integrated agreement is a writing or writings constituting a final expression of one or more terms of an agreement.
(2) Whether there is an integrated agreement is to be determined by the court as a question preliminary to determination of a question of interpretation or to application of the parol evidence rule.
(3) Where the parties reduce an agreement to a writing which in view of its completeness and specificity reasonably appears to be a complete agreement, it is taken to be an integrated agreement unless it is established by other evidence that the writing did not constitute a final expression.