This is valid. But if he appoints him as his agent and the latter says, “I cannot; I am busy,” then the principal leaves, and afterwards the agent regrets it and says, “How can I turn it down?!” Then he accepts and acts on it—this is not valid, because he had rejected it. Once he rejects it, the initial offer issued by the principal is nullified, so a new appointment of agency is required.

His statement, “by any statement or action indicating it,” means, for example, that he says, “I accept,” or, “Certainly.” Likewise, if he takes the item from the person who told him, “I appoint you as my agent to sell this,” without saying a word, and then sells it, this is valid. This is acceptance by conduct.

This principle is not applied consistently by the jurists in all contracts, for they are more stringent in some contracts. The correct view, however, is that all contracts fall under the same principle: every contract is valid through any statement or action indicating it. As for the greater stringency that some jurists have adopted in certain contracts, there is no evidence for it. The basic principle is that this returns to customary practice: whatever people recognize as a contract is a contract, whether it is effected by speech or conduct.

An exception, however, is that which must be witnessed. This must be concluded through an explicit statement, such as marriage. If a man says to someone, “I give you my daughter in marriage,” and he takes the girl and walks away, the marriage contract is not concluded, because it requires witnesses, and mere conduct does not indicate acceptance.

If he says, “I give you this watch as a gift,” and the other person takes it and remains silent, this constitutes acceptance.

Thus, agency has no particular prescribed formula; rather, it is concluded by every statement or action that indicates it. We have said that this should be a general rule for all contracts.