THE NATURE OF AGENCY. 515 has assumed to one of the parties an obligation of which the essence is that he should be under an obligation to the other. In Lawrence v. Fox, for example, B, the obligor, made a promise to A, and thereby assumed a duty to A; but the essence of that duty was that he should also be under a duty to C. It follows that, when B refused to perform his promise, he violated two rights at once. A's right should be enforced in any one of three ways, at his election: first, by a bill in equity to compel B to convey the fund to C, which is specific performance, or, as Professor Langdell somewhere more accurately calls it, specific reparation; second, by an action at law for damages for breach of contract, in which, however, the damages will be nominal; third, by an action for money had and received, in which event he would rescind the contract and recover the consideration paid, and this on the ground of unjust enrichment. C, on the other hand, should have either of two remedies, at his election: first, a bill in equity for specific reparation ; second, an action for money had and received, which would be based, as I said before, not on the ground of unjust enrichment, but on the consensual obligation, and would be the legal counterpart of his bill in equity. It will be observed that he has no right, or rather power, of rescission. The rights in the case of a bill of exchange, or of an insurance policy, or of a trust, while differing in some details, are nevertheless open to the same general analysis. That these relations are really trilateral is shown by the fact that the obligation assumed by B cannot be released except with the consent of the third person. This is perhaps more evident in the case of a trust than in such a case as Law- rence V. Fox. In the case of agency, the trilateral character of the relation becomes even more important than in these last cases, because the much mooted question of what constitutes an agent's authority will be found to turn on it. Whatever else we may say about an agent's authority, it is at least coextensive with his ability legally to bind his principal. Now, in the first place, it will hardly be disputed that whatever the principal tells the agerit he may do, will, when done, be legally valid as the principal's act. Judge Holmes, in an interesting article on agency, says that this is ** plain good sense," introducing no new principle into the law and requiring no explanation.^ In 1 4 Harv. L. Rev. 346, 347.
