Visual Arts: It is surely not entirely fanciful to suggest that the discovery of the mathematical laws of perspective can be regarded as a moment of disaster in the history of Western art, writes John Banville.
When Tomasso de Giovanni di Simone Guidi, known as Masaccio - "Clumsy Thomas" or, as Browning translated it, "Hulking Tom" - unveiled his optical- illusionist painting The Holy Trinity, the Virgin, St John and Donors on the wall of the church of Santa Maria Novella in Florence in 1427, there began a revolution, ominously dubbed by Ernst Gombrich "The Conquest of Reality", which would sweep away the International Style with all its delicacy, tenderness, humour and simplicity. Thenceforward, the straight line would be all.
Before Masaccio, an indisputably great genius who died at the age of 28 - and, indeed, before Brunelleschi, the architect from whom the painter learned the necessary maths - artists had regarded the paint surface as what it is, a flat plane, on which the sense of reality was to be achieved not by a geometrical trick but through a range of wholly painterly effects, such as foreshortening, colour gradation, a mesmerising proliferation of detail, and a conception of the world as a closed, subtly curved system of interlocking and interdependent strata, from God in his Heaven all the way down through angels and saints, men and women, to animals, plants, and demons.
The "rediscovery" in the Renaissance of the works of Plato is no coincidence. The Socratic insistence on the primacy of reason and the scientific method of philosophy, along with the Platonic discrediting of quotidian reality as against a realm of ideal forms, were powerful engines in the Renaissance drive to "make it new". It was Cosimo de' Medici himself who commissioned the great neo-Platonist, Marsilio Ficino, to make translations into Latin of Plato and Plotinus. Armed with the new rationalism, suddenly man was on the move. And "man" is the word: perspectival painting is triumphantly a male form, reflecting a male belief in progress, science, and the perfectibility of man; women, one cannot help thinking, would have known better.
Timothy Hyman's book, another volume in the fine Thames and Hudson World of Art series, posits what he terms "an alternative Renaissance" represented by Sienese art in the two centuries from 1278, when Duccio di Buonisegna undertook his first commission for the city, to 1477 and the transfer by Francesco di Giorgio from Siena to the ducal court at Urbino. Hyman pitches the art of the Sienese painters of the trecento and quattrocento, whose special qualities he defines as "warmth, refinement, fantasy, charm", against Florentine art, with its preponderance of "heroic male figures", forerunners of Michelangelo's and Leonardo's musclebound giants. To the charge that Sienese art is simple to the point of naivety or even comedy, Hyman has a ready response: "Fifteenth-century Sienese painting teaches us that figures resembling dolls or puppets may be closer to our imaginative life than those prodigies of musculature so admired in contemporary Florence."
This is an important point, and represents the essence of Hyman's argument championing Siena against its larger and far more powerful sister-city to the north. Painters in Siena in the 1300s and 1400s, still displaying the influence of Byzantine iconography and, so some scholars contend, of Chinese landscape scrolls - as Hyman points out, European trade with Cathay flourished after Marco Polo's return from the East in 1298 - were essentially artists of the vernacular and the religious, cleaving to, as Hyman writes, "a culture of 'lowliness', of lyrical penitence", through which they sought to show the works of God to man. They also insisted on depicting people solidly inside their urban and natural settings.
Sienese painting had pioneered the integration of figures within city and landscape; Florentine Renaissance painting would take its cue from sculpture, reaching its apogee in a master whose art is only figure - in Michelangelo, for whom the natural world would almost cease to exist.
As Hyman points out, Siena, "created out of a small repertory of building types" in "burnt sienna" brickwork, possessed, and indeed still possesses, a remarkable architectural homogeneity.
This Sienese Gothic vernacular comes to represent the identity of the city, a kind of mother-tongue, for the masters of the 1320s, allowing them to shape from the streets an art of depiction and observations, a new urban realism. But in the 1420s the same architectural idiom is deployed by Sassetta and his generation with a very different inflection: to signpost the lost glory of the republic, and their hope to restore it.
Siena had from earliest days a clear vision of the Ben comun, as in Ambrogio Lorenzetti's astonishing 46-foot-long mural, the Well-Governed City (1337-40), still to be seen in Siena's Palazzo Pubblico. Unlike so many of the Italian city-states, however, Siena put its civic philosophy into practice, instituting a remarkable and complex system of government that lasted for nearly 70 years, from 1287 to 1355. Under this system, nine citizens were chosen by lot to rule for two months, each one holding the chairmanship for one week, and all living together within the Palazzo Pubblico. After the end of their two-month stint, they would not be eligible for re-election for nearly two years. As Hyman writes, "\he system ensured that, over a five-year period, several hundred different individuals would have the leading role in the state".
Inevitably, of course, this form of government favoured the professional and merchant classes; just as inevitably, the nobility, and not only the Sienese nobility, detested it. When the Black Death struck the city in the late 1340s, killing off more than half the population, the nobles, supported by the Emperor Charles IV, seized their chance and overthrew the regime. The box from which the names of the Nine were chosen was flung out of the Palazzo Pubblico, tied to an ass and dragged through the streets, to the approving howls of the mob. The city was never to recover, and in the decades after the plague had died down was subject to repeated invasion by hordes of armed looters, with the covert encouragement of Florence. Hyman: "In the last months of the 14th century, the helpless republic - by then under the rule of upper-class Priori - gave Siena into the possession of the great Milanese warlord, Giangaleazzo Visconti. One of his immediate edicts was to forbid the use of the word popolo."
Yet Sienese art somehow survived, and indeed triumphed again, in the hands of such masters as Sassetta (c. 1392-1450), Giovanni di Paolo (c. 1395-1482), and the anonymous Master of the Osservanza. By the 1480s, however, the glory had faded. Commenting on a plaster relief by Francesco di Giorgio, Hyman delivers a final, sad judgment: "Francesco has abandoned his birthright, the common tongue of the Sienese republic, as a lost cause; he has learnt to compose in the court Latin of the Florentine humanists".
Hyman is an artist as well as a scholar, and it shows, in the keenness of his eye and the warmth of his sympathy for the artists of Siena and their work. His book is a small, or perhaps more than small, masterpiece of art history and appreciation. For those unfamiliar with Sienese painting, and who think of the art of the Italian Renaissance mainly in terms of what Hyman, with a pronounced curl of the lip, calls the " 'progressive' narrative" of Vasari - author of Lives of the Painters (1550) and one of Hyman's blacker bêtes noires - will be captivated by the treasures that the author uncovers for us and, in some cases, recuperates. For anyone planning a trip to Siena this will be an ideal guidebook to the city's art - although many of the works discussed are dispersed to galleries throughout the world - but the armchair-bound reader too will be afforded at least a glimpse of Siena's magnificent "alternative Renaissance".
John Banville's most recent book, Prague Pictures: Portraits of a City, was published earlier this year by Bloomsbury
Sienese Painting: The Art of a City Republic (1278-1477) By Timothy Hyman. Thames and Hudson, 224pp. £8.95