  The term person comes from the Latin persona, whose origins are traceable to Greek drama, where the πρόσωπον, or mask, became identified with the role an actor would assume in a given production. Such usage is carried over today in the word “persona,” referring to characters in fictional literature or drama, or second identities which people adopt for behavior in given social contexts. Its introduction into the mainstream of intellectual parlance, however, came with theological discourse during the patristic period, notably the attempts to clarify or define central truths of the Christian faith. These discussions focused primarily on two doctrines: the Trinity (three “persons” in one God) and the incarnation of the second person of the Trinity (the “hypostatic” union of two natures – divine and human – in one “person”). Confusion marred these discussions because of ambiguities in the philosophical and theological terminology, such that, for example, the thesis – ascribed to Sabellius – would be advanced that in God there was one ύπόστασις and three πρόσωπα, where ύπόστασις conveyed the meaning of “person” and πρόσωπα bore the sense of “roles” or “modes” of being. In order to present these mysteries with precision, the concept of person and the relationship of person to nature needed clarification. The debates culminated in the First Council of Nicaea (325) and the First Council of Constantinople (381), and in the drafting and propagation of the Nicene-Constantinopolitan creed.