A treaty is first and foremost a promise, the treaty must be kept because a promise must be kept. The function of a powerful law, on the contrary, is to allow people to determine, within limits, what the law is or requires. As Joseph Raz says, powerful laws bind certain acts with legal consequences, because “it is desirable to allow people to influence norms and their application in this way if they wish.” With the decline of the label, Contracts provided that “neither the actual nor the obvious intention that a promise is legally binding is essential to the conclusion of a contract”, and the comments refer to the conclusion of a contract despite the erroneous belief of both parties that their agreement is legally unenforceable. And while the black letter rule in England states that “an agreement, although backed by a counterparty, is not binding, because a written contract may consist of a standard agreement or a letter confirming the agreement. . . .