It is ancient learning that a person is free to refuse to accept an appointment as agent but that "acceptance must be followed by execution or prompt resignation." Though such was the law of the Romans of Justinian's time, it has taken our courts many years to reach the same conclusion. Indeed, it was not until the Restatement of Agency was published in 1933 that the basis of liability of one who gratuitously undertook to act as agent for another was expressed in approximately the same form.
Benjamin F. Boye,
PROMISSORY ESTOPPEL: PRINCIPLE FROM PRECEDENTS: II,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol50/iss6/4