The subject of Agency is closely connected, and is a part of commercial and maritime law. One who has a large business, transacted either by land or sea, is bound to employ others to take charge of his affairs along certain lines. The law gives all individuals the right, within certain limitations, to manage and control his own property and incidentally the right to engage others to aid him in doing the same thing. It may be that the skill of another is required in a particular instance, it may be the principal is unable to himself act, because of being otherwise engaged, or he may be physically unable to do the work, because of illness.

A true agency is the relation, that the law creates, from the express or implied contract, entered into between the principal and his agent; the agent being thereby invested with some authority to act for the principal in the management of some dealing with a third person. An ostensible agency is created whenever the principal intentionally causes a third person to believe that another is his agent, and the third person acts on the representation of the principal so made.1

The cardinal principles of the law of Agency are based on the maxims "Qui facit per ahum facit per se," 2 which translated, means "Whatsoever one person does through another, he does himself," and the maxim "Qui per ahum facit, per seipsum facere videtur," which means "He who does an act through the medium of another is deemed, in law, to have done the act himself." The universal application of these principles is restricted by the self evident truth that unless the person known as principal might himself properly do the act, in his own proper person, he could not do it through the medium of another. Therefore if the principal is himself competent to do the thing for himself, then he may do the thing through or by the other person as his agent, making the act his own, in law. The converse of this principle would be true, where the principal is incompetent for any reason to do the act himself, the act of another for him, would not bind him.

1 For other definitions see Ewells' Evans' Agency 1, Mecnem on Agency 1, Story's Agency, Sec. 3. • 4 Harvard Law Review, 347.