Personhood theory

A person is a being, such as a human, that has certain capacities or attributes constituting personhood, which in turn is defined differently by different authors in different disciplines, and by different cultures in different times and places.

In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as he or she was or will be at another time despite any intervening changes.

The common plural of "person", "people", is often used to refer to an entire nation or ethnic group (as in "a people"). The plural "persons" is often used in philosophical and legal writing.

In ancient Rome, the word persona (Latin) or prosopon (πρόσωπον; Greek) originally referred to the masks worn by actors on stage. The various masks represented the various "personae" in the stage play.

The concept of person was further developed during the Trinitarian and Christological debates of the 4th and 5th centuries in contrast to the word nature. During the theological debates, some philosophical tools (concepts) were needed so that the debates could be held on common basis to all theological schools. The purpose of the debate was to establish the relation, similarities and differences between the Λóγος/Verbum and God. The philosophical concept of person arose, taking the word "prosopon" (πρόσωπον) from the Greek theatre. Therefore, Christus (the Λóγος/Verbum) and God were defined as different "persons". This concept was applied later to the Holy Ghost, the angels and to all human beings.

Since then, a number of important changes to the word's meaning and use have taken place, and attempts have been made to redefine the word with varying degrees of adoption and influence.

...
Wikipedia