there are significant differences among the authorities.32 The differences will be discussed below.

§ 3.1.2. Goals of the Rule

Like any legal rule, the parol evidence rule is and should be understood, interpreted, and applied to further its goals. Several goals have been attributed to the rule. Chief among them are (1) implementing the parties’ intention by giving their writing the effect they intended it to have,33

(2) fostering the stability of contractual transactions,34 (3) protecting the integrity and certainty of written contracts,35 and (4) protecting writings because they are more reliable than the memories of the parties.36

Of these, implementing the parties’ intention is the most important. It is the primary goal of contract interpretation generally. Subject to some exceptions, contract law allows the parties to make their own legal relations as an exercise of their autonomy. The exceptions to this general principle do not touch the parties’ choices to integrate all of their operative agreements relating to a transaction into a final, or final and complete, written contract. When they do this, the courts should give effect to their intention to supersede the relevant parol agreements. That they do so is indicated by the universal legal principle that the question of integration turns on the parties’ intention to integrate.37 (As we saw in Chapter 1, ascertaining the parties’ intention is an ambiguous goal.38 However one resolves this ambiguity, though, the primary goal stands as a matter of abstract principle.)

An additional and also important goal is to foster the stability of contractual transactions.39 This goal is often stated but rarely, if ever, explained. It presumes in part that some written contracts should be reliable in themselves. An integrated writing becomes the authoritative guide

32PERILLO, supra note 2, at § 3.2.

33Traudt v. Neb. Pub. Power Dist., 251 N.W.2d 148, 150–51 (Neb. 1977).

34Farmers Coop. Ass’n v. Garrison, 454 S.W.2d 644, 648 (Ark. 1970). See also Berman v. Geller, 90 N.E.2d 843, 845 (Mass. 1950).

35Gianni, 126 A. at 792.

36Garrett v. Ellison, 72 P.2d 449, 451–52 (Utah 1937). See also Masterson, 436 P.2d at 564.

37E.g., Behrens v. S.P. Constr. Co., Inc., 904 A.2d 676, 682 (N.H. 2006).

38See § 1.1.1.

39Varner v. Eves, 990 P.2d 357, 361 (Or.App. 1999); Hercules & Co., Ltd. v. Shama Restaurant Corp., 613 A.2d 916, 928–29 (D.C. 1992).