Homoiousios
Doctrine · On God · c. 358–381
The Son is of like substance with the Father.
The middle term, and the one that came nearest to holding the East together. Its defenders meant by it much of what Nicaea meant by homoousios, and Athanasius said so.
Refused it
- 381 — The First Council of Constantinople (Condemns). Rejects it with the other formulas that had stood against the Nicene word. The Seven Ecumenical Councils (NPNF series 2 vol. 14) · Constantinople I (381), canon 1
Allowed it on their own terms
- 362 — Athanasius of Alexandria (Permits as opinion). Treats those who say of like substance and confess the Son not a creature as meaning the same thing, and declines to press the word on them. New Advent (Fathers and Catholic Encyclopedia) · Athanasius, De Synodis 41
In the disputes
- The Arian crisis Sixty years of argument about whether the Son is God in the same sense the Father is.
First stated in this form after Ecclesiastical History · Socrates, HE 2.45.