Sherwood v. Walker

66 Mich. 568, 33 N.W. 919 (1887)

Supreme Court of Michigan · 1887

Rule

A mutual mistake going to the substance of the thing bargained for, not merely to its quality, renders the contract voidable. Where both parties believed a cow to be barren and she proved fertile, the mistake went to the very nature of the bargained-for animal.

Learning outcomes

By the end of working with this case, you can:

Facts

Walker, a cattle breeder, owned a registered Angus cow named Rose 2d of Aberlone. Both parties believed Rose to be barren and therefore worth only beef value. Sherwood agreed to buy her for roughly eighty dollars based on her weight. Before delivery, Rose was discovered to be with calf, making her worth approximately ten times the agreed price as a breeder. Walker refused to deliver, and Sherwood sued for replevin.

Holding

The Michigan Supreme Court held that Walker could rescind. The mistake was not merely about value; both parties had believed they were dealing in a barren cow, and Rose was in fact a breeder. The error went to the substance of the thing sold, and equity permitted the seller to undo the sale.

Reasoning

Justice Morse drew the distinction that has shaped mistake doctrine ever since: a mistake about quality (the cow weighs more than expected, the gem is worth more than supposed) does not undo a sale, but a mistake about the kind or nature of the thing (a barren cow is a different animal from a breeder) can. Both parties shared the assumption that Rose was barren; that assumption went to the heart of what was being exchanged; the error of that assumption justified unwinding the contract. Justice Sherwood (no relation to the buyer) dissented, arguing that the mistake was about value alone and that the seller should not be permitted to escape a bad bet.

Why it matters

Sherwood v. Walker is the leading nineteenth-century statement of the substance/quality line in mutual-mistake doctrine. The case is taught alongside Wood v. Boynton to expose the difficulty of drawing the line and to motivate the modern reformulation in Restatement (Second) § 152 (mistake as to a basic assumption with material effect on the agreed exchange, and the risk not allocated to the party seeking relief).

The trap

Taking the substance/quality distinction at face value as a freestanding doctrine. Students try to apply it to every mistake case and bog down: every mistake about a material fact can be re-described either as substance or as quality. Sherwood is a museum piece doctrinally; the modern rule is R2d § 152 (basic assumption + material effect) plus § 154 (risk allocation). Both rules produce rescission on Sherwood's facts, but for doctrinally distinct reasons.

The operational intuition the case is designed to break. Naming the trap is what the Socratic exchange is for.

Socratic ladder

The professor's scaffold for the in-class exchange. Each rung is a stage; the questions are scripted prompts, not the punchline.

Surfacing · 45 sec

Q. Walker owns a registered Angus cow named Rose. Both Walker and Sherwood believe she is barren and worth roughly $80 as beef. They agree on the sale. Before delivery, Rose is discovered to be with calf. As a breeder she is worth $750. Walker refuses to deliver. Operationally, who keeps Rose?

Look for: The split. Some students say buyer (a deal is a deal). Some say seller (rescind). Both intuitions track real doctrine.

Holding · 45 sec

Q. What did the Michigan Supreme Court do with the seller's refusal to deliver?

Look for: Held that Walker could rescind. The mutual mistake went to the substance of the thing sold, not merely its quality. Justice Sherwood dissented, framing the error as one of value only.

Reasoning · 120 sec

Q. What does substance versus quality mean here? Both parties agreed they were buying a cow. They got a cow. Why was it a different cow?

Trap: Students take the metaphysical distinction at face value and try to apply it consistently. They cannot. Every mistake can be re-described both ways. The modern frame replaces the metaphysics with risk allocation: R2d § 152 asks about a shared basic assumption, § 154 asks who bore the risk.

Board: R2d § 152 = mutual mistake + basic assumption + material effect + risk not allocated

Push back: Same animal, same identity. What about her was different? The court calls it substance. Could you call it quality and reach the opposite result? What kind of test changes outcomes based on how the lawyer describes the facts?

Push to: R2d § 152. Mistake about a basic assumption that materially affects the agreed exchange, unless the adversely affected party bore the risk under § 154. The modern test asks what the parties assumed and who bore the risk of error, not what the cow really was.

Hypothetical · 90 sec

Vary. Vary one fact. Walker is a professional cattle breeder. Sherwood is a one-time hobby farmer. Both still believe Rose is barren. Pregnancy discovered before delivery. Same result?

Point: The variation introduces expertise asymmetry. Under R2d § 154(b), a party who has reason to know more about the relevant facts may be allocated the risk. The professional breeder may be the cheaper risk-bearer; the court may refuse rescission even on otherwise identical facts. The fact doing the work is who was better positioned to discover the truth.

Integration · 60 sec

Q. You have bought or sold something that turned out to be worth far more or less than expected. Map the transaction onto Sherwood. Was the mistake mutual? Was there a basic assumption? Who bore the risk?

Land: R2d §§ 152 and 154 displaced the substance/quality test. Sherwood is doctrinally a museum piece, kept on the syllabus to surface the difficulty of drawing the line and to motivate the modern reformulation. The modern doctrine asks about risk allocation, not metaphysics. *Ta'amei ha-mitzvot*: the rule serves error allocation, not platonic taxonomy.

Sherwood v. Walker, 66 Mich. 568, 33 N.W. 919 (1887).