ALEXANDER TZONIS

POWER AND REPRESENTATION

THE HERITAGE OF GIOTTO'S GEOMETRY, Samuel Y. Edgerton, Jr., Cornell University Press, 1991, 320 pp., illus., $49.50 (cloth); $27.50 (paper).

FRANCESCO DI GIORGIO ARCH1TETTO, Francesco Paolo Fiore and Manfredo Tafuri, editors, Electa (Milan), 1993, 426 pp., illus., $132.50.

LA GLOIRE DES INGENIEURS, Helene Verin, Albin Michel (Paris), 1993,452 pp., illus.

VILLARD DE HONNECOURT: LA PENSEE TECHNIQUE DUE Xme SIECLE, Roland Bechmann, Picard (Paris), 1991, 384 pp., illus., $86.00.

THE ARCHITECTURAL DRAWINGS OF ANTON10 DA SAN- GALLO THE YOUNGER AND HIS CIRCLE, Christoph L. Frommel and Nicholas Adams, editors, MIT Press, 1994, 522 pp., illus., $95.00.

MILITARY ARCHITECTURE, CARTOGRAPHY AND THE REPRESENTATION OF THE EARLY MODERN EUROPEAN CITY, Martha Pollak, University of Chicago Press, 1991, 120 pp., illus., $15.00.

PAPIERE BOLWERCKEN, Charles van den Heuvel, Canaletto (Alphen aan den Rijn),!991, 248 pp., illus.

What is it that has made Western humanistic culture so "superior" to the other cultures of the world? This question has been asked repeatedly since the 19th century, when the domination of the globe by Western nations became indisputable, through the 1960s, when this domination was finally cast into doubt, up until today, although in a somewhat modified form: what is it that has made Western, male-dominant, ruling-class culture so successful in controlling the world?

The two questions are similar but fundamentally different. The first presupposes a "progress" model of history (Whig, Marxian, Deweyian) and implies the justification of the Western humanistic culture's triumph. The second (post-Marxist, Heidegerrian, "Frankfurtian") departs from a belief, summarized by Paolo Rossi in I filosofi e le macchine (Milan: Feltrinelli, 1962), that Western culture's attachment to the "material world" gave it a "diabolical character," associating it with "enslavement, oppression, exploitation."

Despite this disagreement, both approaches view the "success" of Western culture as a result of some basic agent, although there are different notions as to what that agent is. The possibilities may be divided into four major clusters: the "hardware"-based explanation, which assigns the causes of success to specific gadgets, such as the stirrup, or labor-saving machines; the so-called "constrained resources" explanation, referring, for instance, to the scarcity of labor; the "ideology" explanation, which suggests the emergence of certain strains of thought, such as the Protestant ethic; and, finally, the "software" approach, which focuses on the new cognition, mental instruments, and conceptual systems associated with humanism. "

For decades, major academic battles have been fought over which of these theories was correct. During the last twenty years, however, a more inclusive approach has been favored, indicating a more complex and flexible model of historical explanation. If any preference currently exists, it is for the cognitive, "software" approach, which analyzes the role of mental instruments and conceptual systems, and, in particular, systems of representing knowledge.

There are many reasons for this shift in thinking. Without a doubt, the relatively under-examined state of this area of study makes it attractive from the academic point of view. But there is also enormous interest in developing computer-based knowledge systems where understanding means of representation is fundamental. In a manner of thinking that is typical of Western culture, researchers are turning to knowledge self-reflectively, in hopes of acquiring means for effective production.

Systems of representation, which enable us to describe the world (including the worlds of the past and, possibly, of the future), is the stuff of theory or, to use the medieval and Renaissance term, of science. Through these descriptions, we acquire knowledge of how worlds work, were made to work or might be made to work, and subsequently, of how worlds ought to be made if we would like them to work in a manner we desire.

This latter point has been most characteristic of Western culture. Thus, Western culture appears to have seen representation systems as tied to making and to controlling. Moreover, in developing systems of representation, Western culture appears to have opted repeatedly for those that contribute to making and controlling. This explains the fascination of humanists with perspective and of Western thinkers in general with "realistic," applied systems of representation, including the contemporary preoccupation with pattern-recognition machine vision, CAD, and virtual reality. All these systems capture knowledge in a way in which it can be translated into action directed toward desired targets.

Samuel Edgerton's book, The Heritage of Giotto's Geometry: Art and Science on the Eve of the Scientific Revolution, is a rare example of a study of spatial representations with this particular kind of comparitivist agenda. It examines the nature of the perspectival revolution in the West with the emergence of human- ism, and juxtaposes it with the system of representation used at the same time in the Far East. The emergence and evolution of perspective was not the clear, goal-oriented search that it has been perceived to be.^l With few exceptions, it was more accurately a fuzzy, chaotic movement, which produced several solutions to local problems, many of which were soon forgot- ten but some of which persisted, to be later "recruited" to solve new problems. This is the picture that Edgerton vividly paints. Apparently, no similar movement occurred anywhere else.

Edgerton shows that this system of representation branches into at least two completely different kinds of major applications: illusionism and realistic documentation. China at the time of humanism did not have such a system of representation, according to Edgerton, and that is why its history followed a different path.² The author no doubt exaggerates, slightly polemically, the importance of conceptual factors at the expense of social and economic ones. His work engages in a dialogue with the recent relativist, multiculturalist, and politically correct arguments that claim "during the Renaissance, upper- class patrons championed linear perspective because it affirmed their exclusive political power." Single viewpoint perspective, after all, encourages the "male gaze," hence voyeurism and the denigration of women, police-state surveillance, and the imperialist "marginalization of other." These contentions, which he sees as naively reductive and easily dismissed, do not take into consideration the catalytic role that other social and economic factors could have played in the invention of perspective or in the direction of its applications, such as fortifications and sciagraphia, and in the way it combined with other fields of knowledge, such as algebra.

Edgerton asserts that perspective was not appealing merely because it was an "ideology," because it expressed the repressive "gaze" of the humanists. But neither was its appeal the result of being "natural," following from the "actual and physiological process of human vision." Other systems of representation were equally natural. A stick chart from the Marshall Islands, for example, like perspective, reflected cognitive constraints of topological intelligence. It yielded explanations, predictions, and, ultimately, designs of its own. Yet it did not have the same universal success as perspective. Edgerton acknowledges the more social, contextual factors that contributed to the rise of perspective, particularly in his discussion of Western Europeans' acceptance of the Ptolemaic grid, taking into account the factors of the "opportune moment," the "mental set," the rationalization of capitalism, and the Florentine interest in Ptolemaic cartography.³

The achievement of Edgerton's book is its admirable reconstruction of the critical moments of the process through which perspective was put together as a construct, a conceptual artifact in the midst of the needs and aspirations of an evolving society. The emergence of perspective is one of the most fascinating events in human history, and Edgerton succeeds in explaining it in a compelling manner.

Perspective satisfied four major clusters of needs and aspirations: illusionism, the conception of utilitarian artifacts, their efficient production, and a well- formed symbolic image of the world. The protagonists of its invention exploited earlier theories that were explicitly stated in areas of knowledge such as Euclidean geometry and optics and Ptolemaic cartography, or implicitly embedded in artifacts and objects of antiquity or later works such as Cimabue’s 13th-century frescoes in the basilica of San Francisco in Assisi.

For this reason, the development of perspective has been frequently referred to as a rediscovery rather than an invention. In fact, characteristic of the humanists was the intensity and openness with which they accumulated, incorporated, and cannibalized heterogeneous precedents and ways of thinking - which they in turn applied to a wide range of creative fields. Any major invention of an intellectual system, such as mechanics, Newtonian physics, and the theory of evolution, if investigated with the same kind of analytical rigor Edgerton employs in this study of perspective, would result in a similar characterization.

The most exciting instance of this process of transference, recombination, and reuse of knowledge has been the creative readaptation of the gridded charts of Ptolemy's mappamundi, out of which emerged the visual pyramid, and by extension, the pavimento, or checkerboard pavement. Edgerton shows that neither Filippo Brunelleschi nor Leon Bat- tista Alberti could have drawn their "unprecedented maps of ancient Roman buildings" without the precedent of the Ptolemaic cartographic method.

The uniqueness of Alberti's contribution, on the other hand, and of this particular moment of humanistic activity is the production of his books - in particular, De pictura. This is where the creation of a consistent system of representation and an algorithm of its possible applications occurs. The book's highly abstract, generalized, explicit language would permit a vast number of instantiations on specific domains and in particular uses, from painting to projective geometry to CAD and CAM.

The protagonists of the invention of the new system were involved in satisfying all four clusters of the needs and aspirations of their time. Brunelleschi, Alberti, Francesco di Giorgio, and Leonardo da Vinci all worked on illusionistic, iconic descriptions, such as painting, as well as in map-making, the design of utilitarian artifacts and their production, and the conception of symbolic objects.

Extending the graphic experiments of ]acopo Mariano Taccola, Franceso di Giorgio advanced cut-away views of artifacts in his 1443 treatise De machina. Architects today would call them perspective sections. He also developed transparent views. Both techniques, as Edgerton remarks, "permit us to understand how internal structures look, without the need to build three-dimensional models," facilitating the production of several alternative design solutions.

Nicole d'Oresme, in his 14th-century text Tractatus de latitudine formarum, had already seen the potential of "more clear and easy examination" of problems through the use of "drawn planar figures," which were grasped "rapidly and perfectly through the imagination of the figures. ..help[ing) greatly the knowledge of the thing itself," as Helene Verin observes in her book, La gloire des ingenieurs. Francesco di Giorgio makes the same point in his Quinto trattato, which includes thirty-eight concrete proposals for fortifications described in enough detail to make possible their testing, certainly at least through the "mind's eye." To build as many scaled mock-ups would have been prohibitively costly and time-consuming.

Francesco di Giorgio architetto, the impressive two-volume catalog for the 1993 exhibition in Siena, features not only his architectural works but his great technical achievements as well, including experiments with the still-emerging perspective in both illusionistic painting and designing artifacts. The experiments seem disparate at first, but on closer inspection they are in fact extremely mutually reinforcing. The corpus of the catalog, which was edited by Manfredo Tafuri and Francesco Paolo Fiore, consists of illustrations from Francesco di Giorgio's Trattati, in which he continues the medieval tradition of superimposing images of heterogeneous objects to demonstrate symbolic analogies between the human body and the building. Accordingly, he does not take into account the three-dimensionality of the corresponding objects, despite the fact that perspective would have served that purpose. There is only one drawing, of a head, that points to the possibility of using more modem techniques to express an archaic idea. More exploratory and more modem are the perspective/section drawings of buildings, which place the viewer's eye higher than Alberti's recommendations, thus defeating Alberti's illusionistic aims though permitting a better testing of the relation between plan and interior elevations.

The most exciting application of the new system of representation by Franceso di Giorgio is in his drawings of machines. Unfortunately, this otherwise inclusive catalog contains very little of this system of representation in terms of both illustrations and analysis. It does include, however, a major essay by Nicholas Adams on the military architecture of Francesco di Giorgio, illustrated with excellent photographs of fortresses and several examples of drawings from De machina. Here, we see many of his prolific attempts to reach the optimal triangular bastion solution, none of which succeeded. This is because his system of representation, which could so efficiently and effectively map the spatial form of the fortifications, was not suited to capturing the key function contained in the form-namely, the offensive- defensive, or "lines of fire," representing the function of shooting.

Francesco di Giorgio architetto presents a sketch of a villa with angular bastions and orecchioni (trunnions) depicting "lines of fire." The drawing, which has been attributed to Francesco di Giorgio, is classified in the catalog as anonymous and, in my view, rightly so. The significance of this depiction is more than philological. It involves the role of representation systems in the invention of one of the most revolutionary building types of the Renaissance and one of the key instruments of Western power: the bastion.

If this drawing was by Francesco di Giorgio, it would have been the only exception out of dozens in which the function of shooting is explicitly described. Could he have been responsible for such an invention, and could he have presented it only once, in an isolated drawing from the corpus of his treatises? It is doubtful. Furthermore, what makes it most improbable epistemologically is that nowhere in his work is there a trace of any preliminary studies that could have led to the discovery of the "lines of fire" representation.

Who, then, was responsible for this new representation system that proved to be so significant to Western power? The representation of process through a line drawing was and still is a difficult task because drawings are by nature static. They lend themselves better - that is, more directly - to mapping space. It is a fact that Francesco di Giorgio drew so-called exploded views of artifacts. This new kind of representation of parts of objects was instructive about how objects could be taken apart and put together. Yet process is only suggested here, not depicted.

To my knowledge, the earliest explicit representation of assembling and disassembling an object is an anatomical drawing by Leonardo da Vinci, which, with the aid of dotted lines, shows "the exploded view of the three upper cervical vertebrae." The dotted lines represent the process of fitting of parts. The idea is that the line on the paper is like the trace left behind on the ground by a moving object. Leonardo was obsessed with the representation of processes, which Kenneth D. Keele's clearly explicates in his monumental Leonardo da Vinci's Elements of the Science of Man (New York: Academic Press, 1983). The book documents various problems involving process and function, showing Leonardo's struggle to describe various states of objects over time. Most often he used multiple pictures or overlaps of images, as in his depictions of the variations in the distribution of weight of a human body during movement, of a bird in gliding flight, or, in a famous example, of a horse bucking and rearing.

Leonardo was preoccupied with the representation of shadows, an art known as sciagraphia, wherein perspective was applied in order to trace lighted versus non-lighted regions on a plane given an object and a source of light. It was this expertise that led him to invent a system of representation appropriate for the design of fortifications.⁴ At first, sciagraphia had little to do with the representation of process. But given the fact that the theory of light was based on a ballistic paradigm, one can imagine how a line tracing light could be seen as representing process. It also makes it easier to understand how it was ultimately Leonardo, an expert on sciagraphia, who finally succeeded in constructing a system for representing lines of fire by analogy to the system for representing lines of light and of vision. Thus, the new system for designing fortifications combined two systems of representation-perspective, or simply planar projections, with a system for representing lines of fire. It made possible the development of an algorithm of optimal design of fortifications, the triangular bastion system, and precipitated unprecedented military know-how in the West.

The notion that optimal fortification design methods were invented during the Renaissance is challenged by Roland Bechmann in his book Villard de Honnecourt: La pensée technique au XUe siècle et sa communication. With extensive commentary, this interesting book republishes the well-known 13th-century manuscript by Villard of thirty-three double-sided parchment folios. Using advanced ultraviolet techniques, Bechmann has revealed some interesting figures which had been hidden in the drawings until now. He focuses on Villard's descriptions of utilitarian artifacts, among them a curious pentagon (from Folio 21) annotated by Villard as a five-sided tower. Backed by the ghost image of the manuscript, Bechmann returns to Eugene Viollet-le-Duc's theory that this drawing describes not simply a tower but a tower flanked by triangular bastions. He goes on to argue that certain obscure lines on the drawing are nothing but lines of fire, and concludes that the "principles systematized and applied by Vauban existed before him" - in other words, they already existed in the time of Villard. This is a forced conclusion in a book filled with otherwise very interesting discussions and illustrations. Unfortunately, inventions, including new systems of representation, do not emerge in sudden bursts of intuition ex nihilo.

In La gloire des ingenieurs, an insightful study on technology, Verin discusses in great detail the complexities of the evolution of engineering and the decisive role of drawing in its formation, and, ultimately, in bringing about the power and world-wide control of the West. Once the system of representation was invented, fortification problem-solving required neither a major explosion of intelligence nor routine work. Verin's rich study, which pays much attention to problems of representation and epistemology, opens with an institutional analysis of the emergence of the engineer. The discussion reminds that engineering, like architecture and painting, is not comprised of abstract ideas which find their manifestation in specific practices; it is the other way around. Particular social practices, born in certain contexts, together with knowledge, are formed at particular moments in time and are given specific labels to distinguish them from other practices and ways of thinking.

Verin's book is a macroscopic account of the evolution of technical intelligence from the 16th to the 18th century, which appeared as a rather coherent development of engineering methods and techniques. Despite progress made during this period, however, designers were forced to grapple with numerous, complex local problems that were not solved by major innovations and inventions. For example, a new method of fortification could be applied to a site once the basic concept of the fortress was established, but it could not inform decisions about whether to make a fortress octagonal or decagonal, for example. Moreover, the method could not stipulate whether the polygon should have sides of equal length, or what the lengths should be. Landscape irregularities, existing buildings, and older fortifications were constraints that demanded great inventiveness from the designer, who had to struggle through several revisions of the basic concept.

This is precisely the kind of problem that is illuminated by the superb publication The Drawings of Antonio da Sangallo the Younger and His Circle, which contains examples of fortification designs taken from the Sangallo archive in the Uffizi in Florence. Edited by Christoph L. Frommel, codirector of the Biblioteca Herziana in Rome, and Nicholas Adams, professor in the department of architectural history at Vassar College, the book includes an introduction by Frommel, and essays on the fortification drawings by Adams and Simon Pepper, on the fortified cities Castro and Nepi by Hildegard Giess, and on the drawings of machines, instruments, and tools by Gustina Scaglia.

This publication of the Sangallo archive allows readers to observe a designer's struggle to conceive, with the aid of the drawing, function-driven objects, as once was only possible with the works of painters and, more recently, architects whose works have been archived. Subtitled Fortifications, Machines, and Festival Architecture, this is the first volume of a projected multivolume set which will include almost all the drawings in the Uffizi by Antonio the Younger and his workshop. This book is particularly interesting as a history of technology rather than of city planning. Moreover, the detailed commentaries on each drawing promise to be helpful for any interpretative work to follow. The book also contains provocative material on architectural methodology, such as one study of the proportions of an atrium. The drawing shows Antonio the Younger's numerical proportioning, citing Vitruvius and disregarding Cesare Cesariano' s translation. It is worth noting that this rather sophisticated investigation of proportioning is presented alongside a drawing for a combination grist-mill and pulverizer engine, an object that mixes utilitarian and aesthetic concerns, sketched by Antonio the Younger during his trip to Romagna in 1526 to inspect fortifications.

The initial diffusion of the representation system for designing optimal fortifications and military engines in general was made possible by manuscripts. Francesco di Giorgio's manuscript circulated widely, as did Leonardo's notes to a lesser degree. The first printed treatise using the new system of representation for military architecture, Pietro Cataneo's I quattro primi libri di architettura, is one of the seventy-three that comprise Martha Pollak's Military Architecture, Cartography, and the Representation of the Early Modern European City. This handsomely illustrated book contains a checklist of treatises on fortification in the Newberry Library in Chicago. The examples, published in Europe and England between 1554 and 1725, are each accompanied by a brief descriptive blurb. In contrast to Pollak's more global view of books on military architecture, Charles van der Heuvel's Papier Bolwerken (Paper bulwarks) concentrates on Italian town planning and fortification in the low countries between 1540 and 1609, with special attention paid to the role of drawing. Especially noteworthy is chapter six, which deals with the introduction and reception of Italian fortification and city planning in Dutch architectural theory. The author focuses particularly on the role of Simon Stevin, a true humanist with expertise and accomplishments in various disciplines, including mathematics, engineering, economics, linguistics, fortifications, and city planning.

For all the publishing activity that occurred in the 16th century, the publication of books disseminating knowledge developed by Francesco di Giorgio and Leonardo was curiously delayed for over half a century. Edgerton offers a sociological and political explanation: the publication of another book with more archaic ideas, Roberto Valturio's De re militari. Edgerton argues convincingly that Valturio's thinking, notoriously out of step with the developments of his time, was basically aimed at legitimizing the authority of despotic lords such as Sigismondo Malatesta, lord of Rimini. This legitimation was carried out by what is called "antiquization," or giving to the ruling lord the aura of a despotic but legitimate ruler of the past. This practice, mainly a 16th-century one, was directed by classical scholars who knew antiquity well and could dress up current settings and rulers in bygone imperial clothes - an act for public consumption as well as for the rulers themselves, who fancied themselves, as Edgerton says, ''as retired legati legionum romanarum."

Valturio, in contrast to Brunelleschi, Francesco di Giorgio, and Leonardo, was not an artificer. He was a distinguished classical scholar of his time. According to Edgerton, Valturio instructed his illustrator to purposely archaize the images in the book. These anachronistic images were extremely popular and discouraged for almost half a century the publication of books containing images executed through the new representation techniques.

In discussing the invention of the new system of representation, Edgerton shows how its emergence depended on conditions of pre-existing knowledge, such as Euclidean geometry and cartography. In the case of Valturio, he demonstrates that, even when a new invention has been carried out conceptually, its reception is not guaranteed. The Valturio incident embodies a paradox: while the new system of representation may have been driven by the desire for ever more power and control, the social and political complexities that accompany such power and control can cause exactly the opposite effect. In other words, the turnings of history, even for those who believe in the existence of "progress" and "reality," are in the end completely unpredictable.

NOTES

1. For more, see A. Tzonis and L. Lefaivre, "The Two New Sciences of Representations," DBR 27 (Spring 1992): II-IS.

2. For insight into the means of representation of architec- tural space in China, see Zhai pu zhi yoa (Essentials of house manual), a 420-page manual published in 1741, esp. volume three; also Yu Li, "Comparing and Controlling Number- Based Design Reasoning Systems," Ph.D. diss., Design Knowledge Systems Group, TUDelft, Netherlands, 1994. The main preoccupation of the 16th-century Chinese text is to control through a symbolic measurement system the dis- tances between the standard components of a building. The famous feng-shui manuals are also relevant. Once more, the representation system chooses, abstracts, and controls aspects of site related to a complex system of prohibitions and permissions. The system is also made to accommodate complex combinatorial aspects, out of which a variety of land forms may be categorized and identified. See Xiao Dong Li, "Meaning of the Site," Ph.D. diss., Design Knowledge Systems Group, TUEindoven, Netherlands, 1993.

3. S. Edgerton, journal of the Society of Architectural Histori- ans 33 (December 1974).

4. Leonardo da Vinci is attributed with the invention of the bastion in A. Tzonis, "The Bastion as a Mentality," in C. de Seta, ed., La citta e Ie mura (Rome: Laterza, 1989).