n1 Corbin suggests that, even in situations where the court concludes that it would not have been natural for the parties to make the alleged collateral oral agreement, parol evidence of such an agreement should nevertheless be permitted if the court is convinced that the unnatural actually happened in the case being adjudicated. (3 Corbin, Contracts, § 485, pp. 478, 480; cf. Murray, The Parol Evidence Rule: A Clarification (1966) 4 Duquesne L. Rev. 337, 341-342.) This suggestion may be based on a belief that judges are not likely to be misled by their sympathies. If the court believes that the parties intended a collateral agreement to be effective, there is no reason to keep the evidence from the jury.