Stewart v. Salamon was a United States Supreme Court case that addressed the issue of whether a contract between two parties was valid. The case involved a contract between the plaintiff, Stewart, and the defendant, Salamon, in which Salamon agreed to pay Stewart a certain sum of money in exchange for Stewart's services. The Supreme Court held that the contract was valid and enforceable. The Court reasoned that the contract was supported by consideration, meaning that both parties had given something of value in exchange for the other's promise. The Court also noted that the contract was not against public policy, as it did not involve any illegal activity. The Court also held that the contract was not voidable due to any lack of capacity on the part of either party. The Court noted that both parties were of sound mind and had the capacity to enter into a contract. Finally, the Court held that the contract was not voidable due to any fraud or misrepresentation on the part of either party. The Court noted that there was no evidence that either party had made any false statements or had acted in bad faith. In conclusion, the Supreme Court held that the contract between Stewart and Salamon was valid and enforceable.

Justice Field delivered the dissenting opinion in Stewart v. Salamon, arguing that the majority's decision was inconsistent with prior Supreme Court precedent and should be overturned. He argued that under existing law, a contract between two parties could not be enforced if it had been made without consideration or for an illegal purpose; thus, he believed that the court should have found against Salamon on this basis. Furthermore, Field noted that although there were some exceptions to this rule of law - such as contracts involving real estate - they did not apply in this case since no real estate was involved. In conclusion, Justice Field maintained his belief that the lower court's ruling should stand and Salamon should be held liable for breach of contract due to lack of consideration and/or an illegal purpose behind their agreement.