What is "hypostatic union"

Hypostatic \Hy`po*stat"ic\, Hypostatical \Hy`po*stat"ic*al\, a.

1. Relating to hypostasis, or substance; hence, constitutive, or elementary.

   The grand doctrine of the chymists, touching their three hypostatical principles.
   --Boyle.

2. Personal, or distinctly personal; relating to the divine hypostases, or substances.
   --Bp. Pearson.

3. (Med.) Depending upon, or due to, deposition or setting; as, hypostatic cognestion, cognestion due to setting of blood by gravitation.

   Hypostatic union (Theol.), the union of the divine with the human nature of Christ.
   --Tillotson.

Union \Un"ion\ (?; 277), n. [F., from L. unio oneness, union, a single large pearl, a kind of onion, fr. unus one. See One, and cf. Onion, Unit.]

1. The act of uniting or joining two or more things into one, or the state of being united or joined; junction; coalition; combination.

   Note: Union differs from connection, as it implies that the bodies are in contact, without an inter?ening body; whereas things may be connected by the in???vention of a third body, as by a cord or chain.

2. Agreement and conjunction of mind, spirit, will, affections, or the like; harmony; concord.

3. That which is united, or made one; something formed by a combination or coalition of parts or members; a confederation; a consolidated body; a league; as, the weavers have formed a union; trades unions have become very numerous; the United States of America are often called the Union.
   --A. Hamilton.

4. A textile fabric composed of two or more materials, as cotton, silk, wool, etc., woven together.

5. A large, fine pearl. [Obs.]

   If they [pearls] be white, great, round, smooth, and weighty . . . our dainties and delicates here at Rome . . . call them unions, as a man would say ``singular,'' and by themselves alone.
   --Holland.

   In the cup an union shall he throw, Richer than that which four successive kings In Denmark's crown have worn.
   --Shak.

6. A device emblematic of union, used on a national flag or ensign, sometimes, as in the military standard of Great Britain, covering the whole field; sometimes, as in the flag of the United States, and the English naval and marine flag, occupying the upper inner corner, the rest of the flag being called the fly. Also, a flag having such a device; especially, the flag of Great Britain.

   Note: The union of the United States ensign is a cluster of white stars, denoting the union of the States, and, properly, equal in number to that of the States, displayed on a blue field; the fly being composed of alternate stripes of red and white. The union of the British ensign is the three crosses of St. George, St. Andrew, and St. Patrick in combination, denoting the union of England, Scotland and Ireland, displayed on a blue field in the national banner used on shore, on a red, white, or blue field in naval ensigns, and with a white border or fly in the merchant service.

7. (Mach.) A joint or other connection uniting parts of machinery, or the like, as the elastic pipe of a tender connecting it with the feed pipe of a locomotive engine; especially, a pipe fitting for connecting pipes, or pipes and fittings, in such a way as to facilitate disconnection.

8. (Brewing) A cask suspended on trunnions, in which fermentation is carried on. Hypostatic union (Theol.) See under Hypostatic. Latin union. See under Latin. Legislative Union (Eng. Hist.), the union of Great Britain and Ireland, which took place Jan. 1, 1801. Union, or Act of Union (Eng. Hist.), the act by which Scotland was united to England, or by which the two kingdoms were incorporated into one, in 1707. Union by the first intention, or Union by the second intention. (Surg.) See To heal by the first intention, or To heal by the second intention, under Intention. Union down (Naut.), a signal of distress at sea made by reversing the flag, or turning its union downward. Union jack. (Naut.) See Jack, n., 10. Union joint. (Mech.)

   1. A joint formed by means of a union.

   2. A piece of pipe made in the form of the letter T.

      Syn: Unity; junction; connection; concord; alliance; coalition; combination; confederacy.

      Usage: Union, Unity. Union is the act of bringing two or more things together so as to make but one, or the state of being united into one. Unity is a state of simple oneness, either of essence, as the unity of God, or of action, feeling, etc., as unity of design, of affection, etc. Thus, we may speak of effecting a union of interests which shall result in a unity of labor and interest in securing a given object.

      One kingdom, joy, and union without end.
      --Milton.

      [Man] is to . . . beget Like of his like, his image multiplied. In unity defective; which requires Collateral love, and dearest amity.
      --Milton.

Hypostatic union (from the Greek: hypóstasis, "sediment, foundation, substance, subsistence") is a technical term in Christian theology employed in mainstream Christology to describe the union of Christ's humanity and divinity in one hypostasis, or individual existence.

The First Council of Ephesus in 431 AD recognized this doctrine and affirmed its importance, stating that the humanity and divinity of Christ are made one according to nature and hypostasis in the Logos.