What is a "person" in law?

Persons are the subject of rights and duties; and, as a subject of a right, the person is the object of the correlative duty, and conversely. The subject of a right has been called by Professor Holland, the person of inherence; subject of a duty, the person incidence. "Entitled" and "bound" are the terms in common use in English and for most purposes they are adequate. Every full citizen is a person; other human beings, namely, subjects, who are not citizens, may be persons. A person is such, not because he is human, but because rights and duties are ascribed to him. The person is the legal subject or substance of which the rights and duties are attributes. An individual human being considered as having such attributes is what lawyers call a natural person. (Pollock, First Book Jurispr. 110; Gray, Nature & Sources of Law, Ch. II)