# Inwood v. Ives: The Two-Part Test That Defines Contributory Trademark Infringement

> How a fight over look-alike generic capsules gave trademark law its enduring 'induces or knowingly supplies' standard for holding suppliers liable for someone else's infringement.

Topic: Trademarks  |  Author: Lidiia Levitska  |  Source: Intellectual Property Law (outsideipcounsel.com)
Canonical: https://outsideipcounsel.com/blog/inwood-labs-v-ives-contributory-infringement-standard/


A dispute over the color of generic heart-medicine capsules produced one of the most quoted sentences in American trademark law. In *Inwood Laboratories, Inc. v. Ives Laboratories, Inc.*, 456 U.S. 844 (U.S. 1982), the Supreme Court, in an opinion by Justice Sandra Day O'Connor, set out the standard for when a manufacturer or distributor can be held liable for a trademark infringement actually committed by someone downstream. That standard—intentional inducement, or continuing to supply a product to a party the seller knows or has reason to know is infringing—has governed contributory trademark liability for more than four decades and now anchors the law of online marketplaces, flea markets, and other intermediaries.

## At a glance

- **Case:** *Inwood Laboratories, Inc. v. Ives Laboratories, Inc.*, 456 U.S. 844 (U.S. June 1, 1982).
- **Court:** Supreme Court of the United States; opinion by Justice Sandra Day O'Connor, with concurrences by Justice White and Justice Rehnquist.
- **Posture:** On certiorari from the Second Circuit, which had reversed a judgment for the generic manufacturers; the Supreme Court reversed the Court of Appeals.
- **Holding:** A manufacturer or distributor is contributorially liable for infringement under the Lanham Act if it intentionally induces another to infringe, or if it continues to supply its product to one it knows or has reason to know is engaging in infringement.
- **Significance:** Articulated the durable two-part test for contributory trademark infringement and, in a famous footnote, the classic definition of functionality.

## Look-alike capsules and mislabeling druggists

Ives Laboratories made a drug called cyclandelate, which it sold under the registered trademark CYCLOSPASMOL in distinctively colored capsules. After Ives's patent on the drug expired, generic manufacturers—including Inwood Laboratories and Darby Drug Co.—began selling generic cyclandelate in capsules that copied those same colors. Copying the appearance of an off-patent drug is itself lawful, and pharmacists are generally free to fill prescriptions with cheaper generics.

Ives's theory of liability was indirect. It alleged that some pharmacists were dispensing the generic capsules but labeling them as CYCLOSPASMOL, thereby passing off the generic as the brand. The mislabeling pharmacists were the direct infringers. Ives argued that the generic makers, by selling identical-looking capsules, were contributorially responsible for that downstream deceit. It sued under Section 32 of the Lanham Act, 15 U.S.C. 1114. The case thus squarely raised when a lawful product supplier becomes answerable for the infringing conduct of its customers.

## The standard the Court announced

Justice O'Connor's opinion crystallized the rule that lower courts had developed: "if a manufacturer or distributor intentionally induces another to infringe a trademark, or if it continues to supply its product to one whom it knows or has reason to know is engaging in trademark infringement, the manufacturer or distributor is contributorially responsible for any harm done as a result of the deceit." The test has two independent branches. The first is active inducement—encouraging or instructing others to infringe. The second is knowing continued supply—keeping a customer stocked while knowing, or having reason to know, that the customer is using the product to infringe.

Critically, mere capacity for misuse is not enough. Selling a product that some buyers might use to deceive does not, without more, create liability. There must be culpable inducement or the requisite knowledge tied to actual infringing conduct. That calibrated standard is what has allowed *Inwood* to travel so well: it imposes responsibility on those who feed known wrongdoing without making every supplier an insurer against its customers' bad acts.

## Why the generic makers won

Although *Inwood* is remembered for the standard it announced, the actual outcome favored the generic manufacturers. The district court had found, after trial, that Ives failed to prove either branch of the test: there was no persuasive evidence that the generic makers suggested that pharmacists mislabel the capsules, or that they continued supplying druggists they knew to be mislabeling. The Second Circuit reversed, concluding that the trial court's findings were insufficient and effectively re-reading the record.

The Supreme Court reversed the Court of Appeals on a point of appellate discipline. Under Federal Rule of Civil Procedure 52(a), a trial court's findings of fact may be set aside only if clearly erroneous. The Second Circuit, Justice O'Connor explained, had not held the district court's findings clearly erroneous; it had simply substituted its own interpretation of the evidence, which an appellate court may not do. Reinstating the judgment for the generic makers, the Court underscored that contributory liability is a fact-intensive inquiry resolved by the trial court in the first instance.

## A footnote that shaped functionality law

*Inwood* carries a second legacy almost as influential as its liability test. In a footnote, the Court offered what became the canonical definition of a functional product feature: a feature is functional "if it is essential to the use or purpose of the article or if it affects the cost or quality of the article." That formulation—now called the *Inwood* functionality standard—was later quoted and applied by the Supreme Court in *Qualitex Co. v. Jacobson Products Co.* and *TrafFix Devices, Inc. v. Marketing Displays, Inc.* to keep functional features in the public domain and out of trademark protection. The same opinion that built the framework for secondary liability thus also supplied the test that limits what trade dress can be protected at all.

## Open questions

- **How much knowledge triggers the second branch?** *Inwood* requires knowledge or reason to know, but it did not specify how particular that knowledge must be—an ambiguity that fuels modern marketplace litigation over whether general awareness or specific notice is required.
- **How far does the standard reach beyond manufacturers?** The opinion addressed a product supplier; courts have since extended it to landlords, flea markets, and platforms, raising the question of how to fit a "supply" test to those who provide services rather than goods.
- **What investigative duty, if any, does a supplier owe?** *Inwood* did not decide whether a defendant must affirmatively investigate suspected infringement or may stay passive until it learns of specific violations.

## Implications

- **Two ways to be liable, not one.** A defendant can be reached either for inducing infringement or for knowingly continuing to supply a known infringer; plaintiffs should plead both branches.
- **Knowledge is the battleground.** Because mere capacity to misuse is not enough, contributory cases usually turn on what the defendant knew or had reason to know, and when.
- **Trial findings are hard to overturn.** *Inwood* reinforces that contributory liability is fact-bound and that appellate courts must respect the clearly-erroneous standard.
- **The same case limits trade dress.** The functionality footnote keeps cost- or quality-driven features unprotectable, a constraint counsel must weigh before claiming product configuration as a mark.
- **It is the root of marketplace liability.** Platforms, landlords, and intermediaries are judged by *Inwood*'s descendants, making the 1982 test essential reading for e-commerce disputes.

## Frequently asked questions

**What is the Inwood test for contributory trademark infringement?**
A manufacturer or distributor is contributorially liable if it intentionally induces another to infringe a trademark, or if it continues to supply its product to one whom it knows or has reason to know is engaging in trademark infringement. Either inducement or knowing continued supply will support liability.

**Did Ives win the case?**
No. The Supreme Court reversed the Second Circuit and reinstated the district court's judgment for the generic manufacturers. The trial court had found no proof that the generic makers induced or knew of pharmacist mislabeling, and the appeals court had improperly substituted its own view of the facts.

**Why does Inwood still matter for online marketplaces?**
Its "knows or has reason to know" standard is the foundation courts now apply to platforms, landlords, and service providers. Cases like *Tiffany v. eBay* and the Ninth Circuit's *Brandy Melville v. Redbubble* decision build directly on *Inwood*'s two-part test.

## Authorities and sources

- Supreme Court opinion, Justia: https://supreme.justia.com/cases/federal/us/456/844/
- Cornell Legal Information Institute, full text: https://www.law.cornell.edu/supremecourt/text/456/844
- FindLaw case report (456 U.S. 844): https://caselaw.findlaw.com/court/us-supreme-court/456/844.html
- Later application of the functionality footnote, *TrafFix Devices, Inc. v. Marketing Displays, Inc.*, 532 U.S. 23 (2001), Justia: https://supreme.justia.com/cases/federal/us/532/23/