Oscanyan v. Arms Company was a United States Supreme Court case that dealt with the issue of contract law. The case involved a dispute between the plaintiff, Oscanyan, and the defendant, Arms Company, over a contract for the sale of a gun. Oscanyan had purchased the gun from Arms Company, but the gun was defective and did not work properly. Oscanyan sued Arms Company for breach of contract, claiming that the gun was not fit for its intended purpose. The Supreme Court held that Arms Company was liable for breach of contract. The Court found that Arms Company had failed to fulfill its contractual obligations by providing a defective gun. The Court also held that Arms Company was liable for damages, as Oscanyan had suffered a financial loss due to the defective gun. The Court's decision in Oscanyan v. Arms Company established that a seller of goods is liable for breach of contract if the goods are not fit for their intended purpose. This decision has been cited in numerous subsequent cases involving contract law.

Justice Field delivered the dissenting opinion in OSCANYAN v. ARMS COMPANY, arguing that the majority's decision was wrong and should be overturned. He argued that the contract between Osacnyan and Arms Company did not contain a clause allowing for rescission of the agreement due to non-payment, as had been claimed by Osacnyan. Instead, he argued that it only provided for damages if payment was not made on time or at all. Furthermore, Justice Field noted that even if there were such a clause in place, it would have been void under California law since contracts could not include clauses which allowed one party to unilaterally rescind an agreement without cause or notice to the other party involved. Finally, he concluded by noting that while Arms Company may have breached their duty of good faith when they failed to deliver goods on time as promised in their contract with Osacnyan; this breach did not entitle him to rescind his obligations under said contract nor did it give him any right beyond seeking damages from Arms Company for failing to fulfill its contractual duties