Podcast Summary
Podcast: New Books Network
Episode: Johannes Zachhuber, "Gregory of Nyssa: on the Hexaemeron: Text, Translation, and Essays" (Oxford UP, 2025)
Date: December 22, 2025
Host: Mike Motilla
Guests: Johannes Zachhuber & Anna Marmodoro
Episode Overview
This episode explores the new Oxford University Press volume "Gregory of Nyssa: on the Hexaemeron: Text, Translation, and Essays," the inaugural entry in the "Library of Early Christian Philosophy" series. Host Mike Motilla is joined by editors Johannes Zachhuber and Anna Marmodoro to discuss Gregory of Nyssa's "On the Hexaemeron" (On the Six Days of Creation), situating it at the crossroads of late antique philosophy, theology, and the development of Christian intellectual traditions. The conversation delves into the methods and motivations behind the new series, the complexities of Gregory's intellectual world, key philosophical themes, and the enduring value—and neglect—of this challenging text.
Meet the Editors (07:14–09:48)
Johannes Zachhuber:
- Professor of historical and systematic theology at Oxford.
- Has a longstanding scholarly engagement with Gregory of Nyssa, dating to his doctoral studies nearly 30 years ago.
- Describes Gregory as a figure he has "never quite managed" to stop working on:
"I've tried to get away. Not very hard, but I've never quite managed." (07:44)
Anna Marmodoro:
- Italian-born philosopher, now at Saint Louis University.
- Background in metaphysics and analytic philosophy.
- Became interested in Gregory during her decade at Oxford, drawn to late antique texts straddling both pagan and Christian traditions.
- Sees her role as building bridges between analytic philosophy and theology/classical studies.
- Emphasizes the multi-perspective, interdisciplinary nature of their project.
About the Series: Library of Early Christian Philosophy (09:48–14:18)
Purpose:
- To treat early Christian texts as genuinely philosophical works, not just vessels of theological doctrine or classical echoes.
- To create a "canon" of critical texts available in the original with philosophically sensitive translations and interpretative essays.
Structure:
- Text presented in the original with an English translation.
- Accompanying essays by diverse specialists (theologians, classicists, philosophers), bringing multiple perspectives to each text.
- Seeks to fill a gap—especially in tracking the diachronic development of core philosophical problems (e.g., causation, creation).
- Aims to inspire scholars and early-career researchers:
"...to inspire other colleagues and also younger researchers, early career researchers and graduate students to just do more in the same line." (12:33 – Anna Marmodoro)
Historical Context of Gregory and the Hexaemeron (14:18–16:49)
Gregory of Nyssa:
- Born c. 330 in Pontus (modern Turkey) into a wealthy Christian family.
- Later bishop, significant player in late 4th-century church politics.
- Known for doctrinal, ascetic, and philosophical writings.
- Overshadowed in his lifetime by his famous brother Basil, but carved an independent intellectual legacy posthumously.
- Gregory's "On the Hexaemeron" engages with philosophical cosmology, analogical reasoning, and empirical observation.
Key Motif:
Gregory as both inheritor and innovator—his project is "shadowed" by classical sources (Plato, Aristotle, Stoics), but always strives for original synthesis.
Approaches to Gregory: Philosophical vs. Theological (16:49–23:10)
The Scholarly Landscape (16:49–21:41)
- Mid-20th century saw renewed interest in Gregory as a "philosophical" Christian thinker.
- Emphasis on Gregory's multifaceted engagement with the Platonic tradition, natural sciences, and classical culture.
Zachhuber on Gregory’s tensions:
"There's constantly in Gregory this tension that on the one hand, he seems to be saying, yes, Basil is the teacher...But at the same time...I can actually do things better than Basil." (18:20)
New Contributions of the Volume
Two innovations:
- Authors sometimes approach Gregory "from the outside," with critical distance (21:41 – Anna Marmodoro).
- The volume offers detailed, line-by-line analysis from different disciplinary angles, uncovering the text's philosophical depth.
Gregory and Basil: Apology or Innovation? (27:28–34:08)
Relationship with Basil’s Hexaemeron (27:28–33:27)
- Gregory’s work positioned as an "apology" or elaboration of his brother's celebrated homilies on creation.
- Basil’s homilies achieved immense cultural success, serving as models of Christian cosmological exegesis.
- Gregory, while ostensibly defending or clarifying Basil, often diverges—sometimes even contradicting him and asserting greater philosophical depth.
- The manuscript tradition: Gregory’s text often appended to Basil’s, suggesting its survival owed as much to Basil’s fame as to Gregory’s merits.
Notable divergence — Anna Marmodoro:
"I show that Gregory...takes himself to go beyond Basil with a little bit more sophistication and maybe more sympathy for Aristotle, as if he had gotten a point more in depth than what his brother did." (32:29)
Key Doctrines and Debates
1. Simultaneous (Double) Creation (34:08–37:12)
- Gregory addresses the "problem of sequential creation": why a perfect, omnipotent God would create the universe in stages.
- Argues for "simultaneous creation": in the first cosmic instant, all things exist in potential—a Big Bang–like cosmic "seed"—before actualization unfolds in time.
- This doctrine diverges sharply from both Basil and ancient literalists.
- Both editors note Gregory’s solution is philosophically unsatisfying, but innovative:
"I don't think there is a successful solution there...but it's really incredibly interesting to look how Gregory and his big mind wrestles with that." (36:25 – Anna Marmodoro)
2. The Meaning of Philosophical “Influence” (37:12–44:17)
- Influence is not citation or direct borrowing, but creative reappropriation of key ideas tailored to new doctrines.
- Early Christian authors, unlike modern scholars, did not have ready access to all source texts; they engaged philosophically rather than textually.
- Stoic influence particularly highlighted (via Gretchen Reydams-Schils’s essay): Gregory draws on Stoic models of an immanent, self-ordering cosmos, but adjusts them for Christian transcendence.
Zachhuber:
"...the vision of the Stoics...to see the world, the cosmos, as...an immanent system that...develops based on principles that are already imminent in the cosmos, that is helpful, even though of course, Gregory wants to add the idea of a creator as transcendent..." (41:13)
Philosophical Deep Dive
3. The "Like Effect, Like Principle" & Creation (44:17–53:22)
Problem:
- How can an immaterial God create a material world, when like produces like?
Aristotle’s ultimate matter thought experiment:
- Strip any object of all properties — what’s left? For Aristotle, “prime matter”: “something” that is neither positively nor negatively characterized.
- Gregory applies this idea to creation:
"...a material object is material, not because there are properties that somehow combined with an entity, namely matter...It's rather than a material object is instantiated properties, properties that occur in the world." (47:24 – Anna Marmodoro)
- Thus, God creates not by making “matter + properties,” but by actualizing properties in concrete existence—sidestepping philosophical traps.
4. Logos in Gregory’s System (53:08–60:40)
Traditional role:
- Early Jewish/Christian reader: Logos as intermediary principle (word, reason, chain of command) between transcendent God and material world (e.g., Philo, Origen).
Gregory’s innovation:
- For Gregory, Logos is no longer a transcendent intermediary (nor simply Christ) but the principle of rational order and sequence within creation itself.
- By studying the orderliness of the natural world, Christians can (indirectly) apprehend God.
- The Logos, order (taxes), and regularity together form a “halo” or analogical bridge between the seen and unseen.
Zachhuber:
"Gregory believes that by observing the natural world, by understanding its regularities and...orderliness, the observation of nature leads us to insights about God, about the Creator." (58:29)
"[He] is really a bit like these sort of 18th century physical theologians...how do we know God? We observe the beauty and the harmony of the cosmos and that gives us a sense of the greatness of, of the Creator." (59:09)
Influence, Neglect, and Enduring Significance (62:01–67:20)
Why was the Hexaemeron neglected?
- Extremely limited circulation in antiquity and Byzantium, especially compared to Basil’s text.
- Manuscript appendices suggest it survived mainly as a supplement, not a primary work.
- Possibly seen as too innovative or diverging too far from authoritative models; also, the text’s technical difficulty and wide-ranging references may have discouraged readers.
Why read it now?
- It is a “window”—a rare, concentrated insight into late antique Christian philosophy.
- Unlocks creative philosophical wrestling with persistent metaphysical and theological issues: causation, properties, interaction of divine and material.
- Serves both historians and philosophers as a model of intellectual boundary-crossing.
Marmodoro:
"...this text is really interesting. [A] window into a large world of interest to metaphysicians, historians of philosophy, theologians, classicists..." (66:25)
Notable Quotes & Highlights
- “You can’t just…take a highlighter and say, like, well, the yellow parts are the Stoic parts and the blue parts are Plato…inclusions and transformations are never so simple.” — Mike Motilla (06:14)
- “We all know about the relationship with the siblings. We can understand the psychology there.” — Anna Marmodoro (33:54)
- “The doctrines they cared about also carried and transformed a classical world with them.” — Mike Motilla (05:59)
- “If you get how things go…you can’t know exactly what is behind them, but you can get like a sense of their presence.” — Mike Motilla on Gregory’s Logos (60:40)
What’s Next for the Series & Editors (67:20–70:12)
- Upcoming volumes on Augustine’s "De Ordine" and Eriugena’s "Vox Spiritualis."
- Next book by Zachhuber: edition/translation of Origen’s Commentary on John.
- Marmodoro's next monograph: Parmenidean Essentialism, exploring metaphysics from Parmenides to Aristotle.
Segment Timestamps
| Segment | Topic | Timestamps | | --- | --- | --- | | Opening & Introductions | Series, Editor Bios | 01:35–09:48 | | About the Series | Philosophy/Theology in Early Christian Texts | 09:48–14:18 | | Gregory’s Historical Context | Biography, Intellectual Background | 14:18–16:49 | | Scholarship and Philosophy | Gregory’s Tensions, Volume’s Approach | 16:49–23:10 | | Gregory & Basil | Literary Relationship, Influence | 27:28–34:08 | | Simultaneous Creation | Key Doctrine | 34:08–37:12 | | Philosophical Influence | Stoics, Plato, Aristotle | 37:12–44:17 | | Like Effect, Like Principle | Marmodoro’s Essay | 44:17–53:22 | | Logos in Gregory | Zachhuber’s Essay | 53:08–60:40 | | Influence & Reception | Why Neglected? Ongoing Value | 62:01–67:20 | | Next in the Series | Upcoming Volumes, Future Work | 67:20–70:12 |
Summary for New Listeners
This episode offers an in-depth look at how a key, but often overlooked, work of late antique Christian philosophy creatively reimagines the boundaries between theology and philosophy. Gregory of Nyssa’s On the Hexaemeron delivers a multi-layered and subtle theory of creation, one that absorbs and adapts classical sources—Platonic, Aristotelian, Stoic—in ways that defy easy “cut-and-paste” analysis. With lively engagement and interdisciplinary perspective, the editors illuminate why such ancient debates not only mattered then, but can still provoke today’s readers and thinkers.
Recommended for:
- Historians of philosophy or theology
- Classicists
- Philosophically inclined theologians
- Anyone fascinated by the creative transformation of tradition
Not to miss:
Zachhuber and Marmodoro’s candid remarks on methodology, the challenge of tracking “influence,” and why philosophers should care about ancient Christian thought.