Yale Lock Manufacturing Company v. James was a case heard by the United States Supreme Court in 1887. The case involved a dispute between the Yale Lock Manufacturing Company and James, a locksmith. The Yale Lock Manufacturing Company had patented a lock and key system and had granted James a license to use the system. James had then made and sold copies of the lock and key system without the permission of the Yale Lock Manufacturing Company. The Supreme Court held that James had infringed upon the patent of the Yale Lock Manufacturing Company. The Court found that James had violated the patent by making and selling copies of the lock and key system without the permission of the Yale Lock Manufacturing Company. The Court also held that the patent was valid and enforceable, and that the Yale Lock Manufacturing Company was entitled to damages for the infringement. The Court's decision in this case established the principle that patent holders have the right to prevent others from making and selling copies of their patented inventions without their permission. This decision has been cited in numerous subsequent cases involving patent infringement.

In the case of Yale Lock Manufacturing Company v. James, Justice Field delivered a dissenting opinion in which he argued that the majority had misconstrued the patent law and failed to recognize its purpose. He asserted that Congress intended for patents to be used as an incentive for inventors by granting them exclusive rights over their inventions, not as a means of preventing competition from other manufacturers who may have independently developed similar products. Furthermore, he noted that while it was true that some parts of Mr. James' lock were identical or nearly identical to those found in Yale's patented design, this did not necessarily mean infringement since there could be multiple ways to achieve the same result without copying another inventor's work directly. In conclusion, Justice Field believed that if Congress wanted patents to protect against independent invention they would have explicitly stated so in their legislation rather than leaving it open-ended and subjecting inventors like Mr. James with potential liability when no actual theft occurred on his part