Movius v. Arthur was a United States Supreme Court case that addressed the issue of whether a contract between two parties was valid. The case involved a dispute between two parties, Movius and Arthur, over a contract for the sale of a piece of land. Movius had agreed to purchase the land from Arthur for a certain sum of money, but Arthur later refused to accept the payment and refused to transfer the deed to Movius. Movius then sued Arthur for breach of contract. The Supreme Court held that the contract between Movius and Arthur was valid and enforceable. The Court found 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 found that the contract was not void for lack of consideration, as Arthur had received something of value in exchange for his promise to transfer the deed. The Court also held that Movius was entitled to damages for Arthur's breach of contract. The Court found that Movius had suffered a loss due to Arthur's refusal to accept the payment and transfer the deed, and that Movius was entitled to recover the amount of money he had paid for the land, plus interest. In conclusion, the Supreme Court held that the contract between Movius and Arthur was valid and enforceable, and that Movius was entitled to damages for Arthur's breach of contract.

In Movius v. Arthur, the Supreme Court was asked to decide whether a contract between two parties should be enforced when it had been made in violation of an existing state statute. The majority opinion held that the contract could not be enforced because it violated public policy and would undermine the authority of the legislature if allowed to stand. However, Justice Field dissented from this decision, arguing that contracts are fundamental elements of private property rights and should only be invalidated by clear legislative intent or constitutional prohibition. He argued further that since there was no such evidence here, enforcing this particular contract would not violate any law or public policy and thus should have been upheld as valid under common law principles.