Thompson v. Libby

26 N.W. 1 (1885)

Quick Summary

Joseph H. Thompson (plaintiff), the logs’ owner, signed a written agreement with Rowland C. Libby (defendant) to sell and purchase the logs.

The defendant claimed a breach of warranty about the quality of the logs and attempted to substantiate the contract through oral testimony.

Facts of the Case

Joseph H. Thompson (plaintiff) owned several logs marked as “H. C. A.” that were cut during the winters of 1882 and 1883 and were located in the Mississippi River or on its banks above Minneapolis. Rowland C. Libby (defendant) agreed to purchase these logs from Thompson through Thompson’s agent, D.S. Mooers.

The agreement, executed by both parties, stated that Libby would buy the logs for ten dollars per thousand feet, boom scale at Minneapolis, Minnesota. The payment was to be made as soon as the scale bills were produced.

Procedural Posture and History

  1. The plaintiff filed a lawsuit against the defendant seeking payment for the purchase of the logs.
  2. The defendant pleaded a breach of warranty, claiming that a warranty was made at the time of the sale regarding the quality of the logs.
  3. The defendant sought to introduce oral testimony to prove the existence of this warranty.
  4. The trial court admitted the parol evidence over the plaintiff’s objection.
  5. Dissatisfied with the trial court’s decision to admit parol evidence, the plaintiff appealed the ruling.
  6. The case was brought before the Minnesota Supreme Court for review.

I.R.A.C. Format


Whether oral testimony to prove a warranty is admissible when a written contract governs the sale and purchase of goods.

Rule of Law

Parol evidence is inadmissible to change terms in a valid written contract. When a written instrument clearly expresses the parties’ legal obligations, no oral evidence can modify it. Warranties in sales contracts are integral and can’t be added orally to a written agreement.

Reasoning and Analysis

The written agreement, on its face and in connection with the law governing its construction and operation, purports to be a complete expression of the entire contract between the parties regarding the sale and purchase of the logs. There is no indication that it is an incomplete or informal memorandum.

Hence, parol evidence is inadmissible to introduce or alter any other term in the agreement. A warranty is integral to the sales contract, not a collateral agreement.

Consequently, evidence related to a warranty cannot be incorporated into a written agreement.


The court held that the trial court erred in admitting parol evidence of a warranty because it was inadmissible under the rule that parol evidence cannot contradict or vary a valid written instrument.

Key Takeaways

  1. Parol evidence is inadmissible to contradict or vary the terms of a valid written instrument.
  2. When parties have deliberately reduced their agreement to writing, it is presumed that the written document includes the entire engagement of the parties.
  3. A warranty in a contract of sale is considered part of the overall agreement and cannot be added to a written contract through oral testimony.

Relevant FAQs of this case

What role does careful documentation play in avoiding disputes, especially in sales contracts?

Careful documentation is vital in preventing disputes, particularly in sales contracts. Clear and detailed written agreements minimize interpretation gaps, reducing the chance of disagreements between parties.

Why is the distinction between a complete written contract and an informal memorandum significant?

The distinction is vital because a complete written contract is presumed to cover the entire agreement, limiting the use of parol evidence. In contrast, an informal memorandum may allow additional evidence, influencing the contract’s interpretation.

When is oral testimony admissible to prove a warranty in a sales contract?

Oral testimony can prove a warranty in a sales contract when the written agreement is incomplete or unclear.

  • For example: If a contract references a warranty without details, oral evidence can clarify the terms.
Last updated

Was this case brief helpful?

More Case Briefs in Contracts