§ 121 Acts in the Law
Vestitive facts—whether they create, transfer, or extinguish rights—are divisible into two fundamentally distinct classes, according as they operate in pursuance of the will of the persons concerned, or independently of it. That is to say, the creation, transfer, and extinction of rights are either voluntary or involuntary. In innumerable cases the law allows a man to acquire or lose his rights by a manifestation or declaration of his will and intent directed to that end. In other cases it confers rights upon him, or takes them away without regard to any purpose or consent of his at all. If he dies intestate, the law itself will dispose of his estate as it thinks fit; but if he leaves a duly executed will in which he expresses his desires in the matter, the law will act accordingly. So if he sells his property, it passes from him in accordance with his declared intent, which the law adopts as its own; but if his goods are taken in execution by a creditor, or vested in a trustee on his bankruptcy, the transfer is an involuntary one, effected in pursuance of the law’s purposes, and not of his at all.
The distinction between these two classes of vestitive facts may be variously expressed. We may make use, for example, of the contrasted expressions act of the party and act of the law. An act of the party is any expression of the will or intention of the person concerned, directed to the creation, transfer, or extinction of a right, and effective in law for that purpose; such as a contract or a deed of conveyance. An act of the law, on the other hand, is the creation, extinction, or transfer of a right by the operation of the law itself, independent of any consent thereto on the part of him concerned. The expression act of the party is one of some awkwardness, however, and it is more convenient in general to substitute for it the technical term act in the law, as contrasted with those acts of the law which we have already defined.306
Acts in the law are of two kinds, which may be distinguished as unilateral and bilateral. A unilateral act is one in which there is only one party whose will is operative; as in the case of testamentary disposition, the exercise of a power of appointment, the revocation of a settlement, the avoidance of a voidable contract, or the forfeiture of a lease for breach of covenant. A bilateral act, on the other hand, is one which involves the consenting wills of two or more distinct parties; as, for example, a contract, a conveyance, a mortgage, or a lease. Bilateral acts in the law are called agreements in the wide and generic sense of that term. There is, indeed, a narrow and specific use, in which agreement is synonymous with contract, that is to say, the creation of rights in personam by way of consent. The poverty of our legal nomenclature is such, however, that we cannot afford thus to use these two terms as synonymous. We shall therefore habitually use agreement in the wide sense, to include all bilateral acts in the law, whether they are directed to the creation, or to the transfer, or to the extinction of rights. In this sense conveyances, mortgages, leases, or releases are agreements no less than contracts are.307
Unilateral acts in the law are divisible into two kinds in respect of their relation to the other party concerned. For in some instances they are adverse to him; that is to say, they take effect not only without his consent, but notwithstanding his dissent. His will is wholly inoperative and powerless in the matter. This is so, for example, in the case of a re-entry by a landlord upon a tenant for breach of covenant; or the exercise of a power of appointment, as against the persons entitled in default of appointment; or the avoidance of a voidable contract; or the exercise by a mortgagee of his power of sale. In other cases it is not so; the operation of the unilateral act is subject to the dissent of the other party affected by it, though it does not require his consent. In the meantime, pending the expression of his will, the act has merely a provisional and contingent operation. A will, for example, involves nothing save the unilateral intent and assent of the testator. The beneficiaries need know nothing of it; they need not yet be in existence. But if they subsequently dissent, and reject the rights so transferred to them, the testament will fail of its effect. If, on the other hand, they accept the provisions made on their behalf, the operation of the will forthwith ceases to be provisional and becomes absolute. Similarly a settlement of property upon trust need not be known or consented to ab initio by the beneficiaries. It may be a purely unilateral act, subject however to repudiation and avoidance by the persons intended to be benefited by it. So I may effectually grant a mortgage or other security to a creditor who knows nothing of it.308
Where there are more than two parties concerned in any act in the law, it may be bilateral in respect of some of them and unilateral in respect of others. Thus a conveyance of property by A. to B. in trust for C. may be bilateral as to A. and B. inter se—operating by the mutual consent of these two—while it may at the same time be unilateral as between A. and B. on the one side and C. on the other—C. having no knowledge of the transaction. So the exercise of a mortgagee’s power of sale is bilateral as between mortgagee and purchaser, but unilateral so far as regards the mortgagor.309