On the Decrees of the Council of Nicaea
For For readers who want to know why Nicaea used the word "of one essence" with the Father; the best short entry into the controversy.
Length About 15,000 words, about an hour.
Written around 350 CE, this treatise emerges from Athanasius's urgent need to defend the Council of Nicaea against sustained Arian attacks. Two decades after the council condemned Arianism, opponents were claiming that the council's language—particularly the crucial term homoousios ("of the same essence")—was unbiblical innovation that betrayed the apostolic faith. Athanasius wrote this defense while bishop of Alexandria, drawing on his direct knowledge of the council's proceedings and his deep engagement with the theological crisis that Arianism posed to Christian orthodoxy.
Athanasius methodically demonstrates that Nicaea's terminology, while not explicitly biblical, accurately captures biblical teaching about Christ's divine nature. He shows how the Arian position—that the Son is a created being, however exalted—inevitably undermines salvation itself, since only one who is truly God can reconcile humanity to God. The treatise carefully explains why the council chose homoousios despite its philosophical associations, arguing that this precise language was necessary to exclude Arian evasions and preserve the gospel's core claim that God himself has acted decisively in Christ. Athanasius reveals how the Arians manipulated earlier theological terminology to serve their heterodox agenda, making new precision essential for orthodox faith.
This work has remained foundational for understanding both the Nicene Creed's development and the theological method that underlies all subsequent orthodox Christology. It demonstrates how the church's doctrinal language develops not through speculative innovation but through faithful reflection on Scripture's witness to Christ under the pressure of serious error. The treatise shows why precision in theological language matters for preserving the gospel itself.
Who should read this: Students of early church history and systematic theology who want to understand how orthodox Christology emerged from biblical exegesis and pastoral concern. This is essential reading for anyone seeking to grasp why the Nicene Creed uses its specific language and how theological development serves biblical fidelity rather than replacing it.
Editions
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- OTHER De Decretis Nicaenae Synodi (New Advent) PDTrans. Archibald RobertsonArchibald Robertson's NPNF translation (1892), revised from Newman's Oxford version, on New Advent, including Eusebius's letter on the council. For readers following the Nicene controversy.
- OTHER De Decretis Nicaenae Synodi (CCEL) PDTrans. Archibald Robertson · 1892Archibald Robertson's 1892 translation on the Christian Classics Ethereal Library's reading pages for volume 4 of the Nicene and Post-Nicene Fathers, with the thirty-two sections under their headings and the NPNF footnotes kept. The same text as New Advent's, free of its revisions; for readers who want the best short entry into the controversy.
- OTHER De Decretis Nicaenae Synodi (Wikisource) PDTrans. Archibald Robertson · 1892Archibald Robertson's 1892 translation in Wikisource's transcription of the Nicene and Post-Nicene Fathers, second series, volume 4: one page per section, footnotes kept, plain text that reads well on a phone. For readers who want the best short entry into the controversy.
- PDF De Decretis Nicaenae Synodi (Internet Archive (NPNF2-04 scan)) PDTrans. Archibald Robertson · 1892A scan of the 1892 volume of the Nicene and Post-Nicene Fathers devoted to Athanasius (University of Toronto copy), with Robertson's translations, his long prolegomena and the notes as printed. Page images of the whole book; this work is in it, for readers who want the text as published.
- 🎧 AUDIO De Decretis Nicaenae Synodi (LibriVox)Trans. John Henry Newman · 2023A free LibriVox audiobook of Newman's translation, read by volunteers; complete.
- PDF De Decretis Nicaenae Synodi (Internet Archive (Library of the Fathers, 1844)) PDTrans. John Henry Newman · 1844A scan of John Henry Newman's Select Treatises of S. Athanasius (Oxford Library of the Fathers, 1842-44), his translation with the long notes that became his Arians of the Fourth Century; this work is in it. The version Robertson revised for NPNF; for readers who want the best short entry into the controversy.
- PDF De Decretis Nicaenae Synodi (Internet Archive (Greek text, St Louis 1879)) PD Greek1879A school edition of the Greek text of the Defence of the Nicene Definition printed at St Louis in 1879 (Concordia), sixty pages, no translation. For readers of Greek.Much harder than the work: Greek only, no translation
- PDF De Decretis Nicaenae Synodi (Internet Archive (Migne PG 25)) PD Greek and Latin1857The Greek text with Migne's Latin translation in parallel columns, in volume 25 of the Patrologia Graeca, volume 25 (1857), scanned whole on the Internet Archive; this work is in it. For readers of Greek or Latin.Much harder than the work: Greek and Latin only, no English translation