The two natures of Jesus refers to the doctrine that the one person Jesus Christ had/has two natures, divine and human. In theology this is called the doctrine of the hypostatic union, from the Greek word hypostasis (which came to mean substantive reality). Early church figures such as Athanasius used the term "hypostatic union" to describe the teaching that these two distinct natures (divine and human) co-existed substantively and in reality in the single person of Jesus Christ. The aim was to defend the doctrine that Jesus was simultaneously truly God and truly man.

Historical development

The doctrine of the hypostatic union (the two natures of Jesus) was adopted as orthodox doctrine at the Council of Chalcedon in 451. Three major schools of theology were involved at the council: Alexandria, Antioch, and the West. The consensus of these three schools in the Chalcedonian Creed illustrates the catholicity (i.e. universality) of the ancient church.  The creed asserted two distinct natures, human and divine, and affirmed the one person of Jesus Christ.

Biblical basis

One of the clearest passages in Scripture concerning the two natures of Jesus comes from John 1 (see on John 1). The Word (i.e. Jesus) "was with God, and the Word was God." Moreover, the Word took on human flesh (John 1:14). Luke's gospel also says that Jesus "increased in wisdom and in stature and in favor with God and man" (Luke 2:52).

Two minds and wills, or one?

"Some conclude that when Jesus took on his human nature he possessed two minds, a human mind and a Divine mind, with the human mind responsible for Jesus' knowledge rather than the Divine mind. Others hold that Jesus had one mind but while in his mortal body he chose to have a subconscious mental part that was inaccessible to the conscious mind and then, after his resurrection, his humanity became dominated by the Divine so his subconscious became accessible.

For an example of the "two minds view", see The Logic of God Incarnate, by Thomas Morris. For the "divided mind" view, which speaks of "two systems of belief [in one mind] to some extent independent of each other", see Richard Swinburne's Christian God, p. 201. For a critique of these, see "The Inclusion model of the Incarnation: Problems and Prospects", by Tim Bayne.

The view that Jesus only has one will is called Monothelitism.

Leo's "Tome"

Leo's Tome refers to a letter in 449 from Pope Leo I to Flavian, Patriarch of Constantinople, expounding the orthodox Christology of the West. In this letter Leo maintains that Jesus Christ is one person of the divine Trinity with two distinct natures that are permanently united. These two natures share properties through the so-called communicatio idiomatum or sharing of attributes between the divine and human natures of Christ. Alexandrian theologians favored this concept. It was used, but found less favor among Antiochene theologians. Leo's statement was directed specifically against the heresy of Eutychianism. This letter was recognized by the Council of Chalcedon (451) as a statement of orthodox Christology.

The Communicatio Idiomatum

"A doctrine that is related to the Hypostatic Union is the communicatio idiomatum (Latin for 'communication of properties'). It is the teaching that the attributes of both the divine and human natures are ascribed to the one person of Jesus. This means that the man Jesus could lay claim to the glory He had with the Father before the world was made (John 17:5), claim that He descended from heaven, (John 3:13), and also claim omnipresence, (Matt. 28:20). All of these are divine qualities that are laid claim to by Jesus; therefore, the attributes of the divine properties were claimed by the person of Jesus. To be continued………….