When young Lucy Pevensie first steps through the wardrobe into the snowy woods of Narnia, she enters more than just a magical land—she walks into a universe constructed according to the intricate cosmological beliefs of medieval Europe. C.S. Lewis, one of the 20th century’s foremost scholars of medieval literature, didn’t simply sprinkle his Chronicles of Narnia with talking animals and mythical creatures. Instead, he carefully built his secondary world upon the sophisticated astronomical, theological, and philosophical frameworks that dominated European thought for over a thousand years.

This wasn’t accidental. Lewis’s deep scholarly engagement with medieval cosmology, culminating in his academic masterwork The Discarded Image, profoundly shaped how he imagined and constructed the world of Narnia. By understanding the medieval “Model of the Universe”—as Lewis called it—we can appreciate how the Chronicles operate not just as children’s stories, but as a deliberate attempt to recreate the “enchanted” cosmos that modernity had abandoned.

Lewis the Medieval Scholar: Building the Foundation

Before Lewis ever imagined a faun with an umbrella in a snowy wood, he was already immersed in what he would later describe as “the medieval synthesis itself, the whole organization of their theology, science and history into a single, complex, harmonious mental model of the universe.” His 1964 work The Discarded Image represents the culmination of decades studying medieval literature, but his fascination with pre-modern cosmology appears much earlier in essays like “Imagination and Thought in the Middle Ages” (1956).

Lewis understood that medieval people inhabited their universe differently than we do. “At his most characteristic,” he wrote, “medieval man was not a dreamer nor a wanderer. He was an organiser, a codifier, a builder of systems.” This systematic approach extended to their understanding of the cosmos itself—a finite, ordered structure with Earth at the center, surrounded by crystalline spheres for the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn, beyond which lay the fixed stars, the Primum Mobile, and finally the Empyrean, the dwelling place of God.

But Lewis didn’t just study this cosmology academically; he advocated experiencing it imaginatively. “Go out on any starry night,” he challenged his readers, “resolutely assuming that the pre-Copernican astronomy is true… The real difference… will then, I predict, begin to dawn on you.” This experiential approach to medieval cosmology would prove crucial to how he crafted Narnia.

The Great Chain of Being in Narnia

At the heart of medieval cosmology lay the Great Chain of Being—a hierarchical structure descending from God through angels, humans, animals, plants, and minerals. This wasn’t merely a classification system but a moral and ontological framework that explained how divine influence flowed through creation. Lewis masterfully recreates this hierarchy throughout the Chronicles.

In Narnia, we see this chain clearly established. Aslan, as the son of the Emperor-over-the-Sea, occupies the highest position, followed by the talking animals who possess rational souls, then the regular animals, plants, and minerals. The distinction between Talking and non-talking beasts echoes the medieval understanding that rationality marks a crucial boundary in the chain of being. When Aslan warns in Prince Caspian that talking animals could lose their speech and return to ordinary animal status, he’s invoking the medieval principle that beings could fall in the hierarchy through moral failure.

The creation scene in The Magician’s Nephew provides perhaps the clearest example of Lewis implementing medieval cosmological principles. Aslan doesn’t create randomly but follows a specific order: first earth and landscape, then plants, then animals, and finally the gift of speech to select creatures. This progression mirrors the Great Chain of Being and echoes medieval interpretations of Genesis that saw creation proceeding through ascending levels of complexity and spiritual significance.

Lewis also understood that in medieval thought, “all power, movement, and efficacy descend from God to the Primum Mobile… which moves the other spheres… Besides movement, the spheres transmit… what are called Influences.” This concept of cosmic influence flowing downward through the hierarchy appears throughout Narnia, where Aslan’s power emanates through various intermediaries—from the talking animals to the noble humans who become kings and queens.

The Planet Narnia Theory: Medieval Astrology in Action

Perhaps the most sophisticated example of Lewis’s use of medieval cosmology emerges in what scholar Michael Ward calls the “Planet Narnia” thesis. Ward argues that Lewis deliberately structured each of the seven Chronicles around one of the classical planets, using their medieval astrological associations to shape the tone, imagery, and themes of each book.

According to Ward’s analysis, The Lion, the Witch and the Wardrobe corresponds to Jupiter, the king of planets associated with majesty, justice, and magnanimity. The Jovial themes permeate the book: the children become kings and queens, Aslan displays royal authority and justice, winter gives way to spring (Jupiter’s warming influence), and Father Christmas appears with his generous, kingly gifts. Even the lion imagery connects to Jupiter, traditionally depicted with a lion in medieval astrology.

Prince Caspian embodies Mars, the planet of war and chivalry. The book focuses on military campaigns, heroic single combat, and the restoration of rightful rule through martial prowess. The martial atmosphere is unmistakably Martian, from Peter’s duel with Miraz to the awakening of militant trees.

The Voyage of the Dawn Treader follows Sol (the Sun), with its emphasis on light, gold, quest, and spiritual illumination. Solar imagery dominates: the golden dragon transformation, the Island of the Star, and the journey toward Aslan’s Country in the uttermost East, where the sun rises. The book’s focus on inner transformation and enlightenment reflects the sun’s traditional association with wisdom and spiritual awakening.

This pattern continues through all seven books, with The Silver Chair corresponding to Luna (Moon) with its themes of dreams, forgetfulness, and underground darkness; The Horse and His Boy to Mercury with its emphasis on travel, communication, and cunning; The Magician’s Nephew to Venus with creation, love, and fertility; and The Last Battle to Saturn with endings, judgment, and apocalyptic themes.

Celestial Hierarchies and Angelic Orders

Medieval cosmology wasn’t just about planetary spheres; it included elaborate hierarchies of spiritual beings. Drawing on Pseudo-Dionysius’s Celestial Hierarchy, medieval thinkers organized angels into nine orders arranged in three triads: Seraphim, Cherubim, and Thrones closest to God; followed by Dominions, Virtues, and Powers; and finally Principalities, Archangels, and Angels nearest to human affairs.

Lewis subtly incorporates these hierarchical principles throughout Narnia. While he doesn’t explicitly name angelic orders, the spiritual beings in his world clearly operate according to hierarchical principles. Aslan himself occupies the highest position, but various other spiritual entities serve as intermediaries: the talking animals often function as divine messengers (like angels), while figures like Father Christmas and the Star in The Voyage of the Dawn Treader serve roles analogous to higher spiritual powers.

The very structure of how divine influence operates in Narnia reflects medieval understanding of cosmic hierarchy. Rather than God acting directly on the material world, divine power flows through intermediaries—just as medieval cosmology taught that celestial influences reached Earth through the nested spheres.

Multiple Realms and the Wood Between the Worlds

Medieval cosmology included not just the physical universe but multiple spiritual realms. Dante’s journey through Inferno, Purgatory, and the celestial spheres exemplifies this multi-layered understanding of reality. Lewis creates his own version in the “Wood Between the Worlds” in The Magician’s Nephew—a place that exists outside normal space and time, connecting multiple universes through pools of water.

This concept reflects medieval ideas about the Empyrean—the highest heaven beyond the physical cosmos where God dwells with the blessed. The Wood serves a similar function as a realm beyond the normal cosmological order, a place where the boundaries between worlds become permeable. When Digory and Polly discover that each pool leads to a different universe, Lewis is imagining something remarkably similar to medieval concepts of multiple spiritual realms connected to but distinct from the physical cosmos.

Enchantment vs. Mechanism: The Medieval Alternative

Lewis’s use of medieval cosmology wasn’t merely academic exercise—it served a deeper purpose. In The Discarded Image, he contrasts the medieval and modern worldviews, noting that medieval people lived in what we might call an “enchanted” universe where spiritual forces directly influenced material events. Modern cosmology, by contrast, presents a mechanistic universe governed by impersonal laws.

Throughout the Chronicles, Lewis consistently presents an enchanted cosmos where spiritual realities directly impact physical events. When Aslan breathes on characters, he literally gives them life and strength—echoing medieval understanding of the Holy Spirit as divine breath. When the Deep Magic operates in The Lion, the Witch and the Wardrobe, it functions not as an arbitrary rule but as a fundamental principle woven into the fabric of reality itself, much like medieval natural law.

This enchanted quality extends to how knowledge works in Narnia. Characters gain wisdom not just through empirical observation but through moral and spiritual development. Lucy’s ability to see Aslan when others cannot reflects medieval epistemology, where spiritual perception was considered at least as important as physical sight for understanding reality.

The Harmony of the Spheres in Narrative

Medieval cosmology included the beautiful concept of the “music of the spheres”—the idea that the movement of celestial bodies created harmonious music audible only to those with spiritual ears. Lewis incorporates this directly into The Magician’s Nephew, where Aslan creates Narnia through song. The Lion’s voice brings forth stars, landscapes, and living creatures in a cosmic symphony that mirrors medieval understanding of how divine harmony structures the universe.

This creative song also reflects medieval Neoplatonic ideas about how divine thought becomes material reality through intermediate stages. Aslan’s song doesn’t create ex nihilo but works through the ordered progression from celestial to terrestrial, from simple to complex, following the same patterns medieval thinkers saw in cosmic emanation from the divine source.

A Universe of Love, Not Force

Perhaps most importantly, Lewis’s Narnia embodies the medieval principle that cosmic motion is driven by love, not impersonal force. Medieval thinkers, following Aristotle and especially Dante, believed that love literally moved the spheres—that the universe operated through attraction toward the divine good rather than mechanical causation.

This principle suffuses the Chronicles. Characters’ actions matter not just for their immediate consequences but for their cosmic significance. Edmund’s betrayal and redemption, Eustace’s transformation from dragon back to boy, Emeth’s acceptance despite serving Tash—all these reflect a universe where moral and spiritual realities have cosmological weight. Love, courage, and faithful service align characters with cosmic order, while selfishness, cruelty, and despair place them in opposition to the fundamental structure of reality.

Conclusion: The Enduring Power of Medieval Vision

Lewis’s achievement in the Chronicles of Narnia goes far beyond creating an entertaining fantasy world. By grounding his imagination in medieval cosmology, he offers readers—especially young readers—an alternative to the disenchanted modern worldview. His Narnia operates according to principles that medieval people would have recognized: hierarchy, purpose, spiritual influence, and cosmic harmony.

This doesn’t mean Lewis was simply nostalgic for a lost past. Rather, he understood that the medieval cosmological imagination offered resources for thinking about meaning, purpose, and spiritual reality that modernity had abandoned but that human beings still needed. Through talking animals, magical worlds, and divine lions, he smuggled the medieval universe back into modern consciousness.

When we read the Chronicles with an understanding of their cosmological foundations, we discover not just children’s stories but a sophisticated attempt to rebuild what Lewis called “the discarded image”—a vision of reality where heaven and earth interpenetrate, where every being has its proper place in a meaningful hierarchy, and where love literally moves the stars. In a scientific age that often struggles with questions of meaning and purpose, Lewis’s medieval cosmos offers not escape from reality but a different way of understanding what reality might be.

The lamp-post that Lucy first encounters in the snowy Narnian woods is more than a gateway to adventure—it’s a beacon illuminating an entire universe structured according to the wisdom of the medieval imagination. And in that light, we might glimpse something we’ve almost forgotten: a cosmos where every creature, from talking mouse to High King, participates in the great dance of existence that connects earth to heaven through bonds of love.