Florence Cathedral

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Florence Cathedral — Santa Maria del Fiore, the Duomo — is the cathedral church of Florence, begun in 1296 and consecrated in 1436, its nave roofed by the vast brick dome that Filippo Brunelleschi raised without external scaffolding. The dome remains the largest brick dome ever built, and for the better part of a century after its completion it was simply the largest enclosed space in the Christian world. The building belongs to architectural and civic history before it belongs to any esoteric one, and that order matters.

The fabric

The first stone was laid on 8 September 1296, on the site of the older church of Santa Reparata, whose foundations still lie beneath the present nave. The commission went to Arnolfo di Cambio, the leading Florentine builder of his generation; after his death the work passed through the hands of Giotto, who turned chiefly to the freestanding bell tower beside it, then Andrea Pisano, and finally Francesco Talenti, who in the mid-fourteenth century enlarged the plan to the dimensions that survive — and in doing so set the crossing at an octagon so wide that no one then living knew how it would ever be vaulted. The masons built the nave, the tribunes, and the great octagonal drum, and stopped at the rim of a hole roughly forty-five meters across, open to the Tuscan sky. For decades the cathedral stood unfinished, its emptiness a standing reproach and an engineering problem nobody had solved.

The solution came from a goldsmith. In 1418 the Opera del Duomo, the works board that governed the building, opened a competition for the dome; in 1420 the commission was awarded to Filippo Brunelleschi, who had trained in metal and had spent years studying the ruins of Rome — the Pantheon above all. His scheme dispensed with the centering, the timber falsework, that every dome of that span had always required, and which Tuscany could not in any case have supplied in such quantity. He built two shells, an inner and an outer, locked together and braced by hidden ribs and stone-and-iron chains girdling the mass like the hoops of a barrel; he laid the brick in a herringbone pattern, a spinapesce bond in which each course helped carry the next, so that the dome rose course by course and held itself up as it climbed. It was finished to the base of the lantern in 1436. The interior diameter is about 45.5 meters and the structure reaches some 116 meters at the tip — a mass of more than four million bricks, raised over an open void, by a man who left no full account of how he had done it. Brunelleschi designed the marble lantern that caps the oculus and crowns the whole; he died in 1446, before it was complete, and lies buried in the crypt of the church he had closed. The dome remains, six centuries on, the largest masonry dome ever constructed.

On 25 March 1436, the feast of the Annunciation, Pope Eugenius IV consecrated the finished cathedral. For the occasion the Franco-Flemish composer Guillaume Du Fay wrote the motet Nuper rosarum flores, sung as the pope entered — one of the most studied pieces of fifteenth-century music, long thought to encode the proportions of the dome itself, until Craig Wright showed that its numbers answer instead to the Temple of Solomon described in scripture, and not to anything in Brunelleschi’s stone. The polychrome marble facade that fronts the nave today is far younger than the rest: the medieval front was dismantled in the sixteenth century and never rebuilt, and the present neo-Gothic screen in white, green, and rose Tuscan marble was designed by Emilio De Fabris and finished only in 1887. The cathedral is the seat of the Archdiocese of Florence and a working church still, at coordinates 43.773, 11.257, at the exact center of the old city.

It does not stand alone. The cathedral forms one element of a sacred complex that includes Giotto’s marble campanile and, facing the west front across the piazza, the octagonal Baptistery of San Giovanni — the oldest of the three, the building where the city baptized its children, including Dante, and the one whose gilded bronze doors Lorenzo Ghiberti spent decades casting, the doors Michelangelo is said to have called fit to be the gates of Paradise. It was Ghiberti whom Brunelleschi defeated for the dome commission, a rivalry that ran back to the Baptistery competition of 1401, so that the two men’s lifelong contest is written into the stones of the piazza itself. Within, the dome’s empty interior was for two centuries a vast unpainted shell; the cathedral floor was paved in polychrome marble in the sixteenth century, and the great liturgical clock on the inner west wall, painted by Paolo Uccello in 1443, still runs counterclockwise on the old Italic reckoning, telling the twenty-four hours from sunset that the city kept before modern time.

The city beneath the dome

What draws the cathedral into the orbit of Western esotericism is less the fabric than the city around it. Fifteenth-century Florence, under Medici patronage, was where the Greek philosophical inheritance returned to Latin Europe at scale. Cosimo de’ Medici, the banker who governed the republic without holding office, set the young Marsilio Ficino to translate the Corpus Hermeticum — the Greek texts attributed to Hermes Trismegistus — ahead of Plato himself, on the conviction that they preserved an ancient wisdom older than and consonant with Christian revelation. Ficino finished that translation in 1463 and went on to render the whole of Plato, and then the Enneads of Plotinus, into Latin, founding what later European readers would call Renaissance Neoplatonism and giving the ancient-theology genealogy, the prisca theologia, its definitive modern form. The informal circle long called the Platonic Academy gathered around him, and the speculative theology of Giovanni Pico della Mirandola took shape in this city, in the parishes and households spread beneath the new dome. Pico, drawn to Florence by Ficino’s circle and binding Hebrew Kabbalah into the synthesis, composed there the nine hundred theses and the oration on human dignity that would make him the most notorious young philosopher in Christendom. None of this happened inside the church — the cathedral hosted no academy and taught no philosophy — but all of it happened within sight of the dome, in a city whose self-image the dome had come to fix. To stand in the piazza was to stand at the symbolic center of the republic that paid for the translations.

The connection is not merely atmospheric. Ficino was a priest of Florence, and he ended his days a canon of this very cathedral; in 1521 the city set a bust of him, carved by Andrea Ferrucci, on the south side of the nave, an honor from the church that had scrutinized but never condemned his magic. The man who handed Europe the Asclepius and the Hermetic books with their talk of god-making is memorialized in marble inside a consecrated Catholic building — the two registers, the pagan revelation and the Christian sanctuary, held in one wall. He read no contradiction in it. Translating the wisdom of the gentiles was, to his mind, a Christian act, the recovery of a first dispensation; the cathedral that contained his tomb-portrait contained the logic that made his life’s work thinkable.

Blood at the altar

The cathedral is woven into Florentine memory in more violent ways. On Sunday, 26 April 1478, during High Mass, a conspiracy of the Pazzi — a rival banking house, in league with Pope Sixtus IV, his nephew Girolamo Riario, and the archbishop of Pisa — struck at the two Medici brothers as they stood among the congregation. The assassins waited for the elevation of the Host, the holiest moment of the liturgy, as their signal. Giuliano de’ Medici was set upon and stabbed to death on the cathedral floor, near the high altar. His elder brother Lorenzo, slashed across the neck, fought free and was hurried by his friends into the sacristy, whose heavy bronze doors were thrown shut behind him while the cathedral erupted around them. The conspiracy failed within hours; the reprisals were savage, with the archbishop and the Pazzi ringleaders hanged from the windows of the government palace, and more than eighty implicated men eventually killed. The blood spilled at the altar fixed Santa Maria del Fiore at the center of the city’s political life, the place where the régime that patronized Ficino and Pico had very nearly ended at the moment of the Consecration.

The same nave that held the Platonist memorial held, within two decades, its loudest antagonist. In the 1490s the Dominican friar Girolamo Savonarola preached his apocalyptic Advent and Lenten cycles from this cathedral to crowds that filled it past capacity, denouncing the worldliness of the Medici city and the paganism of its learning even as Pico, who had become his admirer, lay dying in 1494 and Ficino’s circle scattered with the fall of the Medici that year. The cathedral was the acoustic chamber of the whole drama: the building beneath which the ancient theology had been recovered was also the pulpit from which a friar called the city to burn its vanities. Both currents, the Platonic ascent and the prophetic reckoning, ran through one nave within a single generation. Savonarola was hanged and burned in the Piazza della Signoria in 1498; Ficino outlived him by a year.

The dome painted

Inside the cupola, more than three thousand six hundred square meters of plaster carry one of the largest figural paintings in the world: a Last Judgement commissioned by Grand Duke Cosimo I de’ Medici, begun by Giorgio Vasari in 1572. Vasari — painter, architect, and the first great historian of Renaissance art — completed only the uppermost registers in true fresco before he died in 1574; the work was carried to its end, in secco, by Federico Zuccari, who finished in 1579. The program ascends from the regions of Hell at the base through ranks of the saved, the choirs of saints and the personifications of the virtues and the gifts of the Spirit, to the twenty-four elders of the Apocalypse ringed about the throne of God, with the divine light falling from the real oculus at the summit so that the painted heaven opens onto an actual shaft of daylight. Scholars have read the scheme as informed by the Christianized Neoplatonism then current in Florence — a graded cosmos in which all being streams from a single luminous source and is drawn back toward it, the Neoplatonic ascent turned into iconography. How far any deliberate Hermetic design governs it remains genuinely debated, and claims of hidden esoteric ciphers coded into the building tend to outrun the evidence — as the unraveling of the Du Fay proportion legend warns. The current scholarly weight holds that the philosophy in the Florentine air was Platonic and Neoplatonic first, and only loosely Hermetic; the painting belongs to that climate without being a cryptogram of it.

Scholarship and sources

The standard modern technical study of the dome’s construction is Howard Saalman’s Filippo Brunelleschi: The Cupola of Santa Maria del Fiore (A. Zwemmer, 1980), which reconstructs the building campaign from the Opera del Duomo’s own surviving documents; Ross King’s Brunelleschi’s Dome (Walker, 2000) is the most widely read narrative account of the engineering and the 1418 competition. The proportional reading of the consecration motet, and its correction, are set out in Craig Wright’s “Dufay’s Nuper rosarum flores, King Solomon’s Temple, and the Veneration of the Virgin” (Journal of the American Musicological Society 47, 1994), which showed that the motet’s 6:4:2:3 structure mirrors the biblical Temple of Solomon — the 60, 40, 20, and 30 cubits of 1 Kings — rather than any dimension of the cathedral. For the civic catastrophe of 1478, Lauro Martines’s April Blood: Florence and the Plot against the Medici (Oxford University Press, 2003) is the leading English-language reconstruction.

The Florentine intellectual world the cathedral presided over is documented in the scholarship gathered under Marsilio Ficino: James Hankins’s “The Myth of the Platonic Academy of Florence” (Renaissance Quarterly, 1991) deflated the institutional legend of the Academy from the documents, and Brian Copenhaver’s critical Hermetica (Cambridge University Press, 1992) established that the philosophical foundations of Florentine Hermetism were Neoplatonic far more than Hermetic — the verdict that governs any sober reading of the dome’s fresco. The earliest Hermetic treatise the city’s translators recovered is held in the library as I. Poemandres.

Among the great church-buildings of Latin Christendom, the Florentine dome stands apart by its means: where Milan Cathedral multiplied Gothic verticality in pinnacled marble and Chartres and Notre-Dame de Paris carried their weight on flying buttresses and ribbed vaults, Brunelleschi closed his enormous span without any of it, and Christopher Wren’s later dome at St Paul’s in London would still be reaching, two and a half centuries on, toward the problem he had solved first.

Practitioners and devotees, then as now, came to Santa Maria del Fiore as a place of Catholic worship, not as a monument of occult philosophy. The link between the cathedral and the esoteric tradition is one of setting rather than doctrine: this was the church at the heart of the city where Hermes was read as a sage and Plato as a near-prophet, and where the idea later called the perennial philosophy took its early modern form. The dome that ordered the skyline ordered, in a sense, the world that thought beneath it.

→ In the library: The Corpus Hermeticum (Mead) — I. Poemandres

→ Related: Renaissance Neoplatonism · Neoplatonism · Hermes Trismegistus · St Paul S Cathedral · Notre Dame De Chartres · Marsilio Ficino · Cosimo De Medici · Giovanni Pico Della Mirandola · Corpus Hermeticum · Prisca Theologia · Plato · Asclepius · Milan Cathedral · Notre Dame De Paris