Barton v. Geiler was a United States Supreme Court case that addressed the issue of whether a state court could enforce a contract that was made in violation of a state statute. The case involved a contract between two parties, Barton and Geiler, in which Barton agreed to pay Geiler a certain amount of money for the sale of a piece of property. The contract was made in violation of a state statute that prohibited the sale of property for more than its appraised value. The Supreme Court held that the state court could not enforce the contract because it was made in violation of the state statute. The Court reasoned that the state statute was a valid exercise of the state's police power and that the state had the right to protect its citizens from contracts that were made in violation of the law. The Court also noted that the state had the right to protect its citizens from contracts that were made in bad faith or with the intent to defraud. The Court's decision in Barton v. Geiler established that state courts could not enforce contracts that were made in violation of state statutes. This decision has been cited in numerous cases since then and has been used to support the idea that state courts should not enforce contracts that are made in violation of the law.

Justice Field delivered the dissenting opinion in Barton v. Geiler, arguing that the majority's decision was wrongfully decided and should be reversed. He argued that a contract between two parties is binding on both of them, regardless of whether one party has received any benefit from it or not. In this case, he argued that Barton had agreed to pay Geiler for his services as an attorney and thus was obligated to do so even if no benefit had been conferred upon him by those services. Furthermore, Justice Field asserted that there was sufficient evidence presented at trial which showed that Barton did receive some value from the legal advice given by Geiler; therefore, he should have been held liable for payment under their agreement. Ultimately, Justice Field concluded that since there were facts present which supported a finding of liability against Barton for breach of contract with respect to his agreement with Geiler then it would be unjustified to reverse the judgment entered against him in favor of Geiler below without further consideration being given to these facts first.