Theopedia

Homoousios

Definition

Homoousios is the Greek term, “of the same substance” or “of the same essence,” that the Council of Nicaea adopted in AD 325 to confess the Son’s relationship to God the Father: not a creature of a similar or lesser nature, but one who shares the Father’s own essence.1 The council specified this sense by defining the Son’s generation as being “of the essence of the Father” (ἐκ τῆς οὐσίας τοῦ πατρός) and anathematizing anyone who made him “of another… essence” than the Father’s own.1

Historical Development

Pre-Nicene use and condemnation at Antioch (269)

The word itself was not new or exclusively theological: writers before Nicaea had already applied it loosely to any shared kind, from the souls of men and animals to the stars, so on its own it could mean either “belonging to the same kind” or “one and the same essence numerically.”1 John Gill, defending the Nicene fathers’ right to use a non-biblical term, pointed to earlier orthodox uses of the word and its Latin equivalent “consubstantial”: by Eusebius as reported in Theodoret’s Ecclesiastical History, and by the writer Gill took to be Gregory Thaumaturgus.2 A Synod of Antioch had already rejected the word once, in 269, condemning the term homoousion because of the way Paul of Samosata, whose modalist-leaning Christology the synod was convened to judge, had used it. Gill’s own account of the term’s pre-Nicene history passed over this condemnation in silence.2

Nicaea’s adoption and its own ambiguity (325)

At Nicaea the council chose homoousios over the alternative homoiousios, “of similar essence,” which the Arian party found acceptable precisely because it fell short of asserting numerical identity.1 Because the two words do not actually differ in their ordinary, non-technical sense, the council’s choice between them, and its further step of defining the Son’s generation as “of the very essence of the Father,” is itself the evidence that it meant homoousios in the strict sense: one and the same essence, not a second instance of a shared kind. Read the weaker way, Hodge notes, the creed would make Father, Son, and Spirit three Gods “in the same sense that Abraham, Isaac, and Jacob are three men.”3

Contested from the far side as well

Decades after Nicaea, the Anomoean theologian Eunomius rejected homoousios and homoiousios together: applying either term to the Son, he argued, wrongly implied “a generation and division of the essence” on the one hand or an “equality” with the Father on the other, both of which his system of radical subordination denied.4 The dispute over what exactly “one essence” requires was resolved once the Cappadocian fathers fixed ousia (“essence”) and hypostasis (“person”) as a settled technical pairing, the vocabulary essence and person still use.5

Confessional Witness

The Nicene Creed itself confesses the Son “of one substance with the Father,”6 the English rendering of homoousios. The 1689 Second London Baptist Confession does not use the Greek term, but states the same doctrine in its own vocabulary: Father, Son, and Holy Spirit are “of one substance, power, and eternity, each having the whole divine essence, yet the essence undivided.”7 A doctrine an ecumenical council settled in the fourth century and a Reformed Baptist confession restates in the seventeenth is the wider church’s shared inheritance, not a distinctively Baptist position.

Related Doctrines

References

  1. Charles Hodge, “Chapter VI. The Trinity,” in Systematic Theology, Volume I (New York: Charles Scribner and Company, 1871), 454-55. ↩ ↩2 ↩3 ↩4

  2. Steven Tshombe Godet, “Gill’s Doctrine of the Trinity: Its Importance and Definitions,” in “The Trinitarian Theology of John Gill (1697-1771): Context, Sources, and Controversy” (PhD diss., The Southern Baptist Theological Seminary, 2015), 198-99. ↩ ↩2

  3. Charles Hodge, “Chapter VI. The Trinity,” in Systematic Theology, Volume I (New York: Charles Scribner and Company, 1871), 459-61. ↩

  4. Keith Wesley Goad, “Gregory the Grammatical Theologian,” in “Trinitarian Grammars: A Comparison of Gregory of Nazianzus and Some Contemporary Models” (PhD diss., The Southern Baptist Theological Seminary, 2010), 48, 54. ↩

  5. Keith Wesley Goad, “Gregory’s Grammar for the Trinity,” in “Trinitarian Grammars: A Comparison of Gregory of Nazianzus and Some Contemporary Models” (PhD diss., The Southern Baptist Theological Seminary, 2010), 148, summarizing John McGuckin, St. Gregory of Nazianzus: An Intellectual Biography (Crestwood, NY: St. Vladimir’s Seminary Press, 2001). ↩

  6. Archibald Alexander Hodge, “Chapter VII. Creeds and Confessions,” in Outlines of Theology (New York: Robert Carter and Brothers, 1879), 116-117, quoting the Nicene-Constantinopolitan Creed from Philip Schaff’s Creeds of Christendom. ↩

  7. The Second London Baptist Confession of Faith (1689), chap. 2, “Of God, and of the Holy Trinity,” para. 3. ↩