Gwillim v. Donnellan & Another was a United States Supreme Court case that dealt with the issue of whether a contract between two parties was valid. The case involved a contract between the plaintiff, Gwillim, and the defendants, Donnellan & Another, for the sale of a piece of land. Gwillim had agreed to pay the defendants a certain sum of money for the land, but the defendants had failed to deliver the deed to the land. Gwillim then sued the defendants for breach of contract. The Supreme Court held that the contract between the parties 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 the defendants had promised to deliver the deed to the land, and Gwillim had promised to pay the agreed-upon sum of money. The Court also held that the defendants were liable for breach of contract, as they had failed to deliver the deed to the land. The Court found that the defendants had breached their promise to deliver the deed, and that Gwillim was entitled to damages for the breach. The Court also held that Gwillim was entitled to specific performance of the contract, meaning that the defendants were required to deliver the deed to the land.

In Gwillim v. Donnellan & Another, the Supreme Court was asked to determine whether a contract between two parties could be enforced in a court of law when it lacked consideration and had been made without any legal authority. Justice Field delivered the dissenting opinion, arguing that contracts should not be held invalid simply because they lack consideration or are unauthorized by law. He argued that if such contracts were deemed voidable then all agreements would become uncertain and subject to dispute as each party would have an incentive to challenge them on these grounds. Furthermore, he noted that courts should not interfere with private arrangements unless there is fraud or some other public policy concern involved; otherwise it undermines freedom of contract which is essential for economic progress and development. In conclusion, Justice Field maintained his position that even though this particular agreement may have been lacking in certain respects, it still deserved enforcement under the circumstances presented before the court at hand.