Singer Manufacturing Company v. Rahn was a Supreme Court case decided in 1891. The case involved a dispute between Singer Manufacturing Company and Rahn, a former employee of the company. Singer had sued Rahn for breach of contract, alleging that he had failed to fulfill his contractual obligations to the company. The Supreme Court held that Rahn was liable for breach of contract, as he had failed to fulfill his contractual obligations to Singer. The Court also held that Singer was entitled to damages for the breach of contract, as Rahn had failed to perform his duties as agreed upon in the contract. The Court also held that Singer was entitled to an injunction against Rahn, which would prevent him from engaging in any further activities that would breach the contract. This injunction would remain in effect until Rahn had fulfilled his contractual obligations to Singer. The Court's decision in this case established the principle that a party who breaches a contract is liable for damages and may be subject to an injunction to prevent further breaches. This decision has been cited in numerous subsequent cases involving breach of contract.

In the dissenting opinion of Singer Manufacturing Company v. Rahn, Justice Douglas argued that Congress had not intended to limit patent rights in this case and that the majority’s decision was an overreach of their authority. He stated that when a patent is issued for an invention, it should be considered valid until proven otherwise and noted that there were no clear indications from Congress or any other source indicating they wanted to limit patents in such a way as proposed by the majority. Furthermore, he argued against using public policy considerations as grounds for invalidating patents because doing so would open up too many possibilities for abuse by judges who may have different views on what constitutes good public policy. In conclusion, Justice Douglas believed that if Congress wished to restrict patent rights then they should do so explicitly rather than allowing courts to make decisions based on their own interpretation of what is best for society at large.