Which party is NOT necessary for a contract to be considered binding?

For a contract to be considered binding, it is essential that the parties involved are mentally competent, of majority age, and that the contract has a lawful object. However, the presence of witnesses is not a requirement for a contract to be enforceable. While having witnesses can enhance the validity of certain types of contracts or provide proof in case of disputes, the absence of witnesses does not negate the binding nature of a contract. Thus, a contract can still be legally enforceable even if it lacks witnesses, as long as all other criteria for a valid contract are met.