§ 76 Powers
Yet another class of legal rights consists of those which are termed powers. Examples of such are the following: the right to make a will, or to alienate property; the power of sale vested in a mortgagee; a landlord’s right of re-entry; the right to marry one’s deceased wife’s sister; that power of obtaining in one’s favour the judgment of a court of law, which is called a right of action; the right to rescind a contract for fraud; a power of appointment; the right of issuing execution on a judgment; the various powers vested in judges and other officials for the due fulfilment of their functions. All these are legal rights—they are legally recognised interests—they are advantages conferred by the law—but they are rights of a different species from the two classes which we have already considered. They resemble liberties, and differ from rights stricto sensu, inasmuch as they have no duties corresponding to them. My right to make a will corresponds to no duty in any one else. A mortgagee’s power of sale is not the correlative of any duty imposed upon the mortgagor; though it is otherwise with his right to receive payment of the mortgage debt. A debt is not the same thing as a right of action for its recovery. The former is a right in the strict and proper sense, corresponding to the duty of the debtor to pay; the latter is a legal power, corresponding to the liability of the debtor to be sued. That the two are distinct appears from the fact that the right of action may be destroyed (as by prescription) while the debt remains.
It is clear, therefore, that a power is not the same thing as a right of the first class. Neither is it identical with a right of the second class, namely, a liberty. That I have a right to make a will does not mean that in doing so I do no wrong. It does not mean that I may make a will innocently; it means that I can make a will effectively. That I have a right to marry my cousin does not mean that such a marriage is legally innocent, but that it is legally valid. It is not a liberty that I have, but a power. That a landlord has a right of re-entry on his tenant does not mean that in re-entering he does the tenant no wrong, but that by so doing he effectively terminates the lease.182
A power may be defined as ability conferred upon a person by the law to determine, by his own will directed to that end, the rights, duties, liabilities, or other legal relations, either of himself or of other persons. Powers are either public or private. The former are those which are vested in a person as an agent or instrument of the functions of the state; they comprise the various forms of legislative, judicial, and executive authority. Private powers, on the other hand, are those which are vested in persons to be exercised for their own purposes, and not as agents of the state. Power is either ability to determine the legal relations of other persons, or ability to determine one’s own. The first of these—power over other persons—is commonly called authority; the second—power over oneself—is usually termed capacity.183
These, then, are the three chief classes of benefits, privileges, or rights conferred by the law: liberty, when the law allows to my will a sphere of unrestrained activity; power, when the law actively assists me in making my will effective; right in the strict sense, when the law limits the liberty of others in my behalf. A liberty is that which I may do innocently; a power is that which I can do effectively; a right in the narrow sense is that which other persons ought to do on my behalf. I use my liberties with the acquiescence of the law; I use my powers with its active assistance in making itself the instrument of my will; I enjoy my rights through the control exercised by it over the acts of others on my behalf.184185