Piero's Light

by Larry Witham

  Although perspectiva, or “real perspective,” had been around for a long time, Brunelleschi had invented what would be called “artificial perspective,” a drawing technique that would revolutionize Western painting. When Alberti dedicated On Painting to Brunelleschi and called him a genius as well, he may have been referring to the latter’s invention of a new technique for drawing; however, Alberti did not say so. On Painting presents Alberti’s rules and methods as if he were the inventor himself. Years later, Brunelleschi’s biographer, Antonio di Tuccio Manetti, felt it necessary to proclaim his friend’s priority—“through industry and intelligence he either rediscovered or invented it”—probably because the circulation of On Painting seemed to give Alberti pride of place.22

  As a humanist scribe, Alberti had avoided making On Painting a technical treatise. He wanted to make his work readable. For most of it, he waxes eloquent, adding references to antique writers, myths, and literary sources. Behind it was an Albertian view of the cosmos that was both Pythagorean and Platonist, viewing perception and nature as having roots in the divine laws of number, proportion, and harmony. Having done a little painting himself, Alberti infused On Painting with enough methodology to make it the first-ever instruction book on perspective.

  On Painting begins with a Euclid-style description of what makes forms—points, lines, and surfaces. Then Alberti takes Euclid’s idea of vision being like a triangle, with its apex at the eye, and expands the visual concept to a pyramid. Adhering to Euclid, he explains that objects become smaller in the distance because the angles of the visual rays in the eye become smaller. He then presents a pyramid of vision made up of one central ray and countless peripheral rays (prescient, since modern science would make the biological distinction between a tiny spot of central vision and a larger peripheral vision). For Alberti’s purposes, the central ray locates the “centric point”—a point on the horizon directly across from the viewer. The centric point was the key feature in what became known as the “Alberti diagram” for drawing perspective. All perspective lines met in the point, and, by the same token, the viewer’s distance from that point established additional “distance points” to draw with optical accuracy the lines that went crosswise.

  Alberti’s emphasis on rhetorical eloquence meant that On Painting did not exactly spell out a step-by-step method for drawing perspective, leading to confusion even today on what precisely he was saying. Less known, he also wrote a smaller work, a two-thousand-word tract titled Elements of Painting, which provided the kind of clarifying diagrams that were lacking in On Painting.23 Nevertheless, On Painting presented a simple enough starting point for most people to understand: the starting point was Alberti’s vision of the earth’s surface as receding like the lines and squares on a checkerboard. To visualize this, he speaks in terms of floor tiles, something relevant to painters, showing how they decrease in size and angle as the floor spreads into the distance. With this, he corrected a few erroneous practices by painters, who had simply claimed that each tile shrank by a third as the floor receded.

  Alberti’s most practical suggestion, though, was for the painter to think of his flat painting surface as if it was a window being looked through. The visual rays for seeing an object have an “intersection” point with the window, and this allows the painter to draw “the external lines of the painting” based on a “recording of the outlines” of objects that are seen.24 It is a method later to be called Alberti’s “legitimate construction,” though it may have been used first by Brunelleschi to draw the Florence Baptistery. It was a practical optical method that would be built upon by Piero, Leonardo da Vinci, and the German artist Albrecht Dürer.

  Based on this points-on-a-window concept, Alberti further recommended that painters create a handheld grid (made of threads) to hold up and visually transfer objects to their exact places on the checkerboard scheme in the painting. Already, painters were using stencils or other methods to transfer a shape or drawing onto a wall or panel. With a grid method, though, Alberti was offering a tool that was both practical and theoretical (since it presumed a geometrical theory about visual rays intersecting a plane). Without using such a visual grid, he claimed, it was impossible to correctly draw the figures, objects, and buildings precisely as they are seen in the visual field. A generation later, Leonardo da Vinci would state the concept using a different see-through medium: “Perspective is nothing else than the seeing of a place behind a sheet of glass … on the surface of which all things may be marked that are behind the glass.”25

  Alberti dedicated the rest of his brief treatise to citing the ancients, talking about the good use of color, and encouraging painters to tell great stories with action and emotion (historia)—and, in their own lives, to be exemplary persons. Alas, he decided to skip the debates on biology, “the functions of the eye in relation to vision,” as he said. “This is not the place to argue whether sight rests at the juncture of the inner nerve of the eye, or whether images are represented on the surface of the eye.”26 The biology of vision would be a frontier of discovery delayed for another few centuries. For now, Alberti made the idea of looking through a window a classic Renaissance definition of a painting.

  Over in San­sepol­cro, meanwhile, Piero’s painting of the Baptism of Christ was shaping up very much like a great window, and even like walking through a door into the scenery itself. He was also producing a historia painting with all the marks of the new Renaissance naturalism. In color, form, and perspective, the painting told the tale of the coming of the Messiah. As that project got under way, another story of historic proportions was reaching a dramatic crescendo, driven by a desperate effort of Christendom to unite its disparate parts against the expanding empire of the Ottoman Turks.

  For a half century, the Byzantine Empire, home of the Greek Church, had already been in rapid decline. It had been losing territory to the Muslim Turks from the edges and was simultaneously suffering internal decline from a lack of revivals in the Church and a dysfunctional royal dynasty. The Byzantine emperor, John Palaeologus VIII, would do anything to save his capital, Constantinople, from Turkish conquest. But before the Latin Church could talk seriously with the Greeks about a military defense of the East, or political unity of Christendom, it had to put its own papal house in order.

  Around the time that Brunelleschi had done his Baptistery experiments with perspective, the cardinals of the Catholic Church had resolved the Great Schism, with its three rival popes, by agreeing to a single pope in Rome. This decision, made in 1417 at the Council of Constance, came with a major caveat: the pope had to hold regular councils with the cardinals (from many countries) to share power. An autocratic papacy was naturally reluctant to concede, but shrewdly went along. The multi-year council sessions continued, taking on new names each time, now in Constance, now in Basel, now in Ferrara.

  At the outset of his own reign, Pope Eugenius IV realized that the Council of Basel, as it was going, would undermine his power. So he negotiated with Cosimo de’ Medici to move the Council to Florence.27 Around the time that Alberti unveiled his On Painting, the city of Florence voted to fund preparations for the great council. Some Latin clergy, in fact, started sending personal luggage there. Then Eugenius switched: with the Milanese condottieri controlling the roads between Basel and Florence, he decided that Ferrara was a safer choice. It was an elegant city, fortified with walls and surrounded by a fruitful countryside. Most important of all, Ferrara was near Venice. It made for an easier journey for the Greeks to come to Italy to continue talks about the unification of Christendom under the papacy.

  This assertion of papal authority was bold and risky, and Eugenius needed all the allies he could summon. For such a project with the Greeks, it was not surprising that three of his most stalwart supporters were Hellenists, scholars of the Greek heritage. Two of them were Latin churchmen. Abrogio Traversari of Florence was widely known, of course. The second was a young, up-and-coming German theologian, Nic
holas of Cusa (Cusanus in Latin), who, as a scholar of the Greek language and Platonist thought, had been appointed as a chief negotiator with the Greeks. Eugenius’s third ally was on the Greek side, the scholarly priest Basilius Bessarion of Nicea. In preparation for the Council of Ferrara, Cusanus and Bessarion would travel much, and, when the council commenced, Traversari and Bessarion were drafting its decrees in the Latin and Greek languages.

  To make the council a success, Pope Eugenius was also willing to empty the papal coffers. The expenses were massive, beginning with a fleet of ships to collect the Greeks (and a small army the pope paid for to protect Constantinople while the Byzantine leadership was in Italy). Embarking from Constantinople, the fleet carried seven hundred Greek delegates on their long, delayed journey: first to Venice, then by river or horseback to Ferrara. Cusanus was the Latin diplomat on deck during the storms and tedium of the ocean journey, there to shepherd the Greek flotilla to its destiny. When the council finally convened, the chief authorities were Pope Eugenius IV for the West and, for the East, Byzantine Emperor John VIII and the Greek Church’s Patriarch Joseph. Hundreds of others were constantly at work, including an exhausted Traversari. “It is I who do all this business of the Greeks, translating from Greek into Latin and from Latin into Greek all that is said or written,” he said.28

  The policy sessions began in spring 1438, but a rise of the plague that summer—in Ferrara, Bologna, and Florence—put the entire council in doubt. Slowed by precautions, the council also ran out of money. A now-hesitant pope (who first eyed Venice as a plague-free place to move the council with the Greeks) looked to Florence for help. The Medici and the town council were already reaching out. They offered to pay for a continuation of the council in Florence. Once Eugenius persuaded the reluctant Greeks, promising a four-month cap on the proceedings, the separate entourages of the pope, emperor, and patriarch began to reach the gates of Florence in January 1439.

  The pope and emperor were received with great pomp—the emperor arrived on Carnival day. It was a visual feast, by all accounts. Florentines already dressed brightly. The ornate white garb of the Latin clergy was quite elaborate as well. To the Italians, the secular Byzantine officials and higher Greek clergy were an equally marvelous sight. Clerics wore copes of blue with white and purple stripes. Statesmen donned ankle-length robes with great sashes. Their drooping hats were of gray felt and red silk. Perhaps more than these, the Florentines gawked at the general clerical garb of somber black, topped by Greek stovepipe hats with black veils. In the clean-shaven times of Quattro­cento Italy, the Greek beards also were wondrous to see—a feature still universally painted on Christ but, in real-life Italy, a taste of something exotic.

  On the Greek arrival, Florence was not only in full bloom with its new artistic commissions, but with the humanist enthusiasm for Greek literature. The city chancellor was the literary wit Leonardo Aretino. He addressed the Greeks twice in their native tongue. In the months that followed, the booming voice of Bessarion made an array of official statements. The Greek emperor with his pointed beard wore, by turns, a tall hat with a great jewel or a hat with a long beak-like point. There was plenty more spectacle and drama. At the height of the council, the aged Greek patriarch died (as would Traversari unexpectedly, though it was not until shortly after the council, a time of retreat at a Camaldolese monastery). In Florence, festivities always went ahead. At the end of June, on the Feast of St. John the Baptist, patron saint of the city, a few thousand council delegates jostled through two days of raucous street festivity: processions, displays of wealth, music, banners, effigies, and street theater.

  Florence celebrated another great holiday on July 6. Businesses closed and the population flocked to the cathedral piazza, where the pope and emperor, under Brunelleschi’s dome, decreed a union that ended 437 years of division—in word, at least. The emperor stayed another month. Then he was escorted under a canopy in a regal procession to the city gates, beginning the long journey, by way of Venice, back to Constantinople.

  Six days before the emperor’s ship left Venice (departing on September 13), the Hospital of Santa Maria Nuova paid the painter Domenico Veneziano for his work on frescos in the choir of Sant’ Egidio Church in the hospital complex. And as the records show, Piero was “with him.”29 Piero had seen plenty of festivals back in San­sepol­cro. Bright banners and costumes were nothing new. Even so, Florence must have been visually stunning. His visit would have an impact on his future paintings, where he would feature oriental-style costumes and, as interpreters would suggest, symbolize the tribulations of the Latin and Greek churches.

  A year before the Council of Florence, Domenico Veneziano had been in Perugia, having traveled there from his Florence base for a painting commission. From Perugia he was trying to reach a traveling member of the Medici household, Piero de’ Medici, in hopes of securing a painting commission back in Florence. Domenico assured his Medici patron that he could produce “marvelous things.”30 When Domenico returned to Florence, he would instead be employed by the hospital, which wanted a large fresco. Domenico probably began that project, a series on the life of the Virgin Mary, at the start of 1439, meaning that the fresco was going up as the Greek and Latin delegations swarmed into the city. For some art historians, though not all, the notation about Piero della Fran­cesca being “with” Domenico in Florence, and by implication working alongside him on the hospital frescos, provided an image of Piero as being established in Florence as a teenage apprentice, a view that is now in serious doubt (as this book suggests).31

  Being “with” Domenico is probably more pertinent to Piero’s evolving style than to where he did his apprenticeship. Domenico was apparently a very animated figure. Born in Venice, he had been trained as a painter in Rome and Florence, the city in which he finally settled. His bold use of color and light had been nurtured by working under the late-Gothic colorist Gentile da Fabriano. Along the way, Domenico had also learned of the new classical look, with architectural perspective and realism in human figures. His style would eventually become a benchmark in vivid, solid painting, as evidenced in his (one day to be famous) St. Lucy Altarpiece in Florence. The picture is a tableau of sunlit color. The figures of the Virgin, child, and saints occupy a Renaissance loggia, its tiled floors, arches, and columns all in perspective. The painting represented a Domenico style that, according to art historians, seems to be a precursor of the mature style that Piero would develop.

  By an early dating of Piero’s birth, Piero may have been just two years younger than Domenico.32 While not having the prestige of Domenico’s Roman training and Florentine connections, Piero may have worked with him as a peer, and certainly not as an apprentice. Therefore, in the Florence of 1439, Piero could well have been standing in as an able painter helping with Domenico’s large commission. The chronicler Vasari would alternatively report that the two had actually painted together on the east coast of Italy and in Loreto, where they had fled the plague. This period after Florence may have been the time in which Piero absorbed some of Domenico’s style.

  Whatever the actual relationship and chronology, there is documentary evidence that Piero had been in Florence in 1439. Like anyone who visited, he was struck by the city’s artistic developments, which may have included seeing Alberti’s On Painting. Alberti had written a version in the Tuscan vernacular, but it was probably only in very limited circulation. It would have been hard for Piero to obtain and read a copy, but the message of On Painting was no doubt circulating among the Florentine humanists whom Piero would meet. Not only had Alberti extolled the “virtues of painting,” he had asked society to elevate the status of painters who achieved excellence in the use of perspective, color, form, and historia,33 a sentiment that Piero and Domenico would have only found pleasing to their ears.

  During Piero’s unspecified time in Florence, the theological dimensions of the Council were surely not lost on him either. He could be excused if some of the theological su
btleties escaped his attention: the council debated the bread used in the Eucharist, the Holy Spirit’s procession (from Father or Son), the Latin doctrine of the existence of Purgatory, and the authority of the papacy as heir to St. Peter, the first bishop of Rome. Regardless, in the context of the council, Piero could not have missed the enthusiasm for all things Greek, including the strong doses of Platonism that pervaded humanist and artistic circles.

  Greek thought had arrived in Italy in waves. Depending on the era, it came as mere ripples or with tidal force. The lost works of Aristotle arrived first. When a friend of Thomas Aquinas began translating Aristotle from the Greek and Arab sources, Aquinas produced his Summa Theologiae (1268–73). It was an entirely new system of Christian thought based on Aristotle’s categories. For Aquinas and theologians before him, four categories of Aristotle were particularly helpful: the idea of an ultimate cause; the distinctions between substance and accident; the relationship of potentiality and actuality; and Aristotle’s view that each kind of existence has a “form” that determines its purpose and direction. Such ideas began to underpin Church doctrine. For instance, the Church explained the supernatural power of Eucharistic bread by saying Christ is its substance while the wheat flour is its accident (appearance). Similarly, God as Creator is not only the first cause (falling under Aristotle’s category of “final” cause), but also absolute actuality. By contrast, Creation merely exists in various degrees of potentiality (finally actualized by their inherent forms or by divine intervention).

  By the time Dante died in 1321, Aristotle and Thomism had become the somewhat official philosophy of the Catholic Church. Soon after Dante was gone, the young Petrarch—who was about seventeen when Dante died—came to loathe the Aristotelian hegemony in the universities and schools, with its dry, logic-chopping approach. Unable to read Greek, he was nevertheless inspired by Plato’s “divine torrent of eloquence” in Latin translations. He also found Plato implicit in the teachings of Augustine, who had said “There are none who come nearer to us [Christians] than the Platonists.”34