“This is My Body”; Leon Battista Alberti’s  Re-Discovery of Linear Perspective Theory in the Italian Renaissance

Thomas J. Tobin • English Department • Duquesne University • Pittsburgh, PA 15282

In his De Pictura (1435), Leon Battista Alberti wrote that “the ancients are a source of inspiration for me,” and it is implicit in much of that treatise that Alberti relies heavily on the writings of Ptolemy, Eulcid, and Vitruvius to define his system of mathematical three-dimensional space on a two-dimensional canvas (Alberti 47 ff. and 66 ff.). Since the thinkers and artists of classical Greece and Rome wrote about the key aspects of what we now call “perspective theory,” the question arises as to why this knowledge was lost or forgotten for better than fifteen centuries, between the First Century BCE and 1435. What conditions, what barriers existed which denied the use of a canvas or wall as a “window through which to view a subject” (Edgerton 24), in favor of a more stylistic, iconographic representational mode? Further, how did it come about that perspective theory flourished in Renaissance Florence in the Quattrocentro?
The first question is not as easy to answer as it may seem.  The Catholic Church, with its theo-centric world view, is the first logical choice as the “barrier” against the use of mathematical perspective. One part of this barrier was that the Church placed more emphasis on faith than on mathematical science. Pictures, in a society dominated by such thinking, would be iconic, static, and intended for worship. The relationships among figures in pictures would be hieratic: more important figures would be larger than lesser ones; Christ would be in the center of the picture, with those of lesser importance ranging out toward the edges of the composition. Such a subjective, iconic method of representing the world is indeed found in the art of Byzantine culture, and in early mediæval European styles. 
My second question deals with the cause for overcoming the barriers imposed, as I originally supposed, by the Catholic Church. The answer surprised me, because it seems that it was the Church itself which became the impetus for overturning its own aversion to perspective theory. Perspective theory had not died out all together, as I had supposed, but was being kept alive, albeit just barely, by members of the Franciscan order, like the eminent scholar of the 1200s, Roger Bacon. Another source was the Mid-East’s Arab culture, which never “lost interest” in the study of mathematical perspective at all. The barrier against the use of perspective theory in depicting subjects was not so much a question of the Church’s ideology concerning art, but rather about the way in which Church scholars interpreted the way in which the entire universe was put together.
In order to treat the issue of “losing” linear perspective theory, it helps to define this body of theory according to the writings of the ancients. The Greeks did not think in terms of “perspective theory” per se, but rather concentrated their study on a particular branch of science known as optika (optics). This body of knowledge concerned itself with studying the mechanical operations behind the process of seeing. At the time, there were two opposing theories concerning the nature of sight. The “atomists” held that all objects gave off eidola (eidola), or picture-like effluxes which penetrated the air and then somehow got into the surface of the viewer’s eye with an exact image (Kristeller 111). The Pythagoreans and Stoics objected to this idea, saying that the efflux from something as large as, say, a camel or a mountain could certainly never fit into the small space of the human eye. Instead, they proposed a contrary theory, which stated that a visual force was emitted by the eyes in a sort of cone. These rays of force activate the ether between the object seen and the viewer, and this activation is somehow sensed by the soul, thus making an image for the viewer (Kristeller 112). 
In the fourth century B.C., Euclid wrote his Optica (Optika), which is almost entirely an exercise in geometry. He did not concern himself with the practical aspects of painting or composition, but instead settled many questions about the workings of vision. He postulated that “the force of vision always proceeds from the eyes as visual rays, which can be diagrammed as straight lines” (Edgerton 68). Ptolemy and Galen, later Greek thinkers, stressed that those rays closest to the center of the visual cone carried back to the eye clearer and more precise information of things seen than did those rays which struck the eye more obliquely. Thus the “centric ray,” as Alberti would call it fifteen-hundred years later, following the axis of the visual cone and making right angles with the surface of what is seen, would be the most distinct ray of all (Edgerton 69). This is demonstrated in Figure 1 below.

Figure 1: The visual cone of Ptolemy (Edgerton 68).
The Greeks and Romans were not merely interested in optics only as a theoretical pursuit. The practical aspect of optics for them, however, dealt not so much with picture-making, but with the stage and in architectural matters. Considerable attention seems to have been paid by the Greeks to scenographia (scenographia), the science of painting theater backdrops in what was apparently a form of linear perspective. 
The Roman scholar and architect Vitruvius had worked out a system of painting stage backdrops in which a vanishing point was utilized. His De Architectura, written in the first century B.C., explains his method:
Scenography also is the shading of the front and the retreating sides, and the correspondence of all of the lines to the center of a circle. . .  For to begin with: Agatharchus at Athens, when Aeschylus was presenting a tragedy, was in control of the stage, and wrote a commentary about it. Following his suggestions, Democritus and Anaxagoras wrote upon the same topic, in order to show how, if a fixed center is taken for the outward glance of the eyes and the projection of the radii, we must follow these lines in accordance with a natural law, such that from an uncertain object, uncertain images may give the appearance of buildings in the scenery of the stage, and how what is figured upon vertical and plane surfaces can seem to recede in one part and project in another. (1.2.2 ff.)
Vitruvius is not, in the above quote, writing a technical manual; his discussion of scenography is more theoretical than practical. In layman’s terms, what Vitruvius is talking about is a system by which realistic scenes may be painted which “fool the eye” into extending the space of the stage back further than it actually is. Set designers use these same “dead reckoning” methods of judging perspective in painting stage backdrops today. 
All of the theory which the Greeks and Romans wrote came to naught during the following fifteen centuries. One possible reason for this may lie in the Catholic Church’s position about the way in which the universe is constructed. Scripture posits the creation of the entire universe according to the desires of God, and it is this type of subjective, individualistic thinking which accounts for the lack of a “perspective theory,” either in the writings or the paintings of both the Early Byzantine period and the Middle Ages in Europe. Samuel Edgerton posits a theory somewhat like this in The Renaissance Rediscovery of Linear Perspective, wherein he says that “the ages before the Renaissance were concerned with a subjective interpretation of the Divine plan” (Edgerton 18). Unlike the Renaissance painter depicting his scene in perspective, the mediæval artist viewed his world quite subjectively. He saw each element in his composition as separate and independent, and thus paid little attention to the spatial relationships among objects. The Byzantine artist, too, was absorbed within the visual world which he was representing, rather than standing outside it, observing from a “removed” viewpoint like the Renaissance artist. A passage from Edgerton reinforces my argument:
Let us use the example of railroad tracks to express this distinction in another manner. The post-Renaissance artist will see the rails as forever converging. But what about the railroad engineer? He is “infused” with the tracks, as it were, and hence sees the rails as parallel. The “reality” of the tracks for the engineer. . . depend on quite a different viewpoint from that of the linear perspective painter. (21)
Notice, however, that Edgerton uses the word “different” viewpoint in that last sentence, not “inferior” or “less developed.” The epistemic shift from a subjective to an objective viewpoint in making pictures was not one of progression, but a change from one method to another, equally valid one. 
Where does the Church fit into all of this? The Catholic Church taught that the universe, encomapssing all of God’s creations, was infinite, yet at the same time geo-centric. Thomas Bradwardine, the archbishop of Canterbury in the early 1300s, wrote that “Deus est sphaera infinita cuius centrum est ubique et circumferentia nusquam”  (Kristeller 100). This attitude of the Church about the conception of the universe meant that pictures were intended for worship.  Icons and symbolic representations of Christ and the canon of saints were de rigeur for the artist, from almost the beginnings of Christianity up until the late 1200s.  Mankind was an inferior subject for portrayal, and much less so were beasts, books and buildings. 
The Church also relied heavily on artistic representations of the citizens of heaven because of the general illiteracy of the earthly population. The mediæval populace generally fell into two classes: the uneducated, of whom there were many, and scholarly monks and nobles, of whom there were comparatively few. Since the Church was primarily supported by the tithes and manpower of the uneducated masses, it made sense that the way the Church looked at the universe included a global inferiority complex for all of mankind. Depicting the world, not as the eye sees it, but “as the spirit sees,” to paraphrase Roger Bacon, became one way to exact service and devotion from the masses. A reward of heaven for those who atoned for their sins made for a willing labor force and steady money supply for the Holy See.
Although the mediæval Church helped to keep itself funded and supported through the use of iconic art, it also kept alive the study of mathematics, optics, and perspective theory. While the average Ducento person might have used a book to prop up a table or start a fire, the monks of pre-Renaissance Europe kept and studied copies of ancient writings, such writings often coming by way of the Arabs, who prized mathematical order and “this-worldly” pictorial exactitude. 
Averröes and Avicenna, among many Arab authors, had translated many of the classical Greek works on optika, mathematika, and philosophia (optika, mathematika, and philosophia) into Arabic. From these Arabic texts came translations into Latin (and also German, French, British, and Italian vernaculars) by churchmen during the later Middle Ages. While monk artists made iconic pictures which were intended for worship and didactic teaching, their brothers in the scriptorium were busy learning about Ptolemy’s visual cone and the effects of light on objects. 
The thing which united the Church’s two ways of depicting the world was cartography. By the Quattrocento, voyages of discovery were underway to Newfoundland and along the African coast. Map-making skills now demanded the use of a geometrical system to help depict the intricacies of the land being surveyed. 
Ptolemy had defined, in his Geographica, an affinity between cartography and painting which has a very familiar ring to it: 
The end of chorography [drawing in topographical details on maps] is to deal separately with a part of the whole, as if one were to paint only the eye or the ear by itself. The task of geography is to survey the whole in its just proportion, as one would the entire head. For in an entire painting we must first put in the larger features and afterwards those detailed features which portraits and pictures may require, giving them proportion in relation to one another so that their correct distance apart can be seen by examining them, to note whether they form the whole or part of the picture. (1.1, italics mine)
Ptolemy’s atlas, which included such ideas, reached Florence around 1400 (Edgerton 111). Vitruvius’ writings also included sections on chorography, most likely lifted from Ptolemy. Around 1401, the Florentine sculptor/architect Fillipo Brunelleschi read Vitruvius’ ideas about mathematical perspective (Edgerton 112 ff.). It is no coincidence that the dissemination of such ideas to scholars of the time should set them to thinking about using the methods of perspective in their own art. Masaccio, a younger contemporary of Brunelleschi, used mathematical one-point perspective to design his paintings The Tribute Money (1425) and The Trinity (1427). 
If the new voyages of exploration brought back ancient texts, the factor which allowed fifteenth-century Florentines to study classical Greek and Roman scholars was that for the first time, we see a third division of society coming into being: the middle class. In Trecento and Quattrocento pre-Italy, the newly prosperous and educated middle class took over many of the scholarly functions formerly performed by monks, but with a decidedly anthro-centric viewpoint. Even though most of the great minds of the Renaissance tried to dovetail their theories about the nature of the world with those of Christianity, the net result was almost always a greater role in the universe for man. Vasari, the chronicler of Italian Renaissance figures, says of Leon Battista Alberti:
Very great is the advantage bestowed by learning, without exception, on all those craftsmen who take delight in it, but particularly on sculptors, painters, and architects, for it opens up the way to invenzione in all the works that are made. . . . This man, born in Florence of the most noble family of the Alberti, devoted himself not only to studying geography and the proportions of antiquities, but also to writing, to which he was much inclined, much more than to working. He has given attention to architecture, to perspective, an to painting, leaving behind him books written on these most marvelous subjects. (110) 
Although Alberti never once in his De Pictura overtly describes any painting techniques, the book is famous for its detailed analysis and explication of the exacting geometry of the “new” perspective theory. In reality, there’s nothing new about De Pictura, but it is the first volume where all of its component elements are brought together into a single coherent system. 
The question still remains, though; why does Alberti get the credit? Why not Brunelleschi, or perhaps Masaccio? There is much evidence that painters and architects working in Florence before 1435 had already used mathematical perspective theory. 
Let us return to Masaccio’s Trinity. Executed in 1427, this work shows a knowledge of perspective space very much akin to that described by Vitruvius above. The vanishing point of the composition is placed at five feet nine inches from the floor, the height of an “average” viewer. The architecture depicted in Trinity seems therefore to continue the space of the church of Santa Maria Novella in Florence; Masaccio even uses the same colors and design elements in his fresco that are extant in the church itself.
This use of a two-dimensional space as the plane of a “window” through which an artist depicts three-dimensional scenes is an interpretation of Ptolemy and Vitruvius with which those thinkers might not have agreed; it is a “next step” from theory to practice. Ptolemy had gotten to the stage of theorizing about perspective pictures, and Vitruvius saw enough use for perspective on the stage, but we can find little evidence that either Ptolemy or Vitruvius applied perspective theory to other sorts of pursuits (Kristeller 166). Masaccio’s Trinity represents the manner in which the artists of Renaissance Florence used the methods of perspective to give greater glory to God and the natural world. 
After about 1430, God was still seen as the supreme being, but He had a new twist: He was now a rational and mathematical God. The inherent order of the universe was expressed in humanistic terms, through the divine harmonies of mathematics and geometry. Since God created light first of all things, says Brunelleschi, then light must be the factor by which everything in creation may be seen properly (Wittkower 276). 
Roger Bacon had written about “seeing with man’s eye and with the eyes of God” in 1277 (Kristeller 66), and his sort of philosophy is carried out in the module-based buildings of Brunelleschi  and the paintings of Masaccio.  Why, then, does Alberti receive the laurels for “re-discovering” linear perspective? He wrote down the process by which other artists were already working. Since the written record is the most durable, credit falls to the person who synthesizes and records the work of others. 
Just as Darwin became known for the theory of natural selection in his Origin of Species, even though two other scientists had come up with the same ideas the previous year, Alberti is famous as the author of De Pictura, the “painter’s bible.” Although there is copious evidence to support the argument that perspective techniques were already being used in Quattrocento Italian art, only Alberti had the education, time, and forethought to record these techniques. 
To sum up, it can be seen that something like perspective theory was first thought of by the ancient Greeks and Romans, who did not have much use for it, save to decorate their stages. This knowledge fell into disuse over some fifteen-plus centuries, in large part due to the ideology of the Catholic Church. The ideas concerning perspective were not lost all together, due partially to the scholarship of the Arabs, and in greater part to the scholarship of monks in the very Catholic Church which did not officially see a use for such ideas. In this case, the concepts which Ptolemy discussed did not change, but were deemed irrelevant, until they were once again needed to support a new explanation of the order of the universe.  
The Renaissance in Italy saw the creation of a middle class, whose more secular, anthro-centric ideas made a greater space for geometry and mathematics as humanistic studies, and also made way for the re-introduction of perspective technique in art. The rise of the science of cartography also helped to place stress on the scientias of the universe. The shift toward perspective pictures thus reflected the changing mindset of the Church about the manner in which the world is constructed. 
Finally, even though a careful scholar can see many instances of the use of perspective technique prior to the writing of Alberti’s De Pictura in 1435, Alberti gets credit as the re-discoverer of the theory of perspective because he’s the one who wrote it all down. 

Works Cited
Alberti, Leon Battista. On Painting: The Latin Text of De Pictura. Trans. J. R. Spencer. Connecticut: Greenwood, 1976.
---. Ten Books on Architecture. Ed. J. Rykwert. Trans. J. Leoni. New York: Trans-Atlantic, 1966.
Burckhardt, Jakob C. The Civilization of the Renaissance in Italy. Trans. S. G. Middlemore. New York: Harper, 1958.
Edgerton, Samuel Y. The Renaissance Rediscovery of Linear Perspective. New York: Harper, 1976.
Elkins, James. “Did Leonardo Develop a Theory of Curvilinear Perspective?” Journal of the Warburg and Courtauld Institutes 51 (1988). 190-6.
Gadol, Joan. Leon Battista Alberti, Universal Man of the Renaissance. Chicago: U of Chicago P, 1969.
Kristeller, Paul O. Renaissance Thought and Its Sources. New York: Columbia UP, 1975.
Ptolemy. Geographica. Trans. O. Neugebauer. New York: Penguin, 1959.
Vasari, Giorgio. Lives of the Most Eminent Painters, Sculptors, and Architects. Abridged. Ed. R.N. Linscott. New York: Linscott, 1959.
Vitruvius. De Architectura. Ed. and trans. Frank Granger. London: Kelmscott, 1934.
Wittkower, Rudolf. “Brunelleschi and ‘Proportion in Perspective.’” Journal of the Warburg and Courtauld Institutes 16 (1953). 275-91.
White, John. “Developments in Renaissance Perspective--I.” Journal of the Warburg and Courtauld Institutes 12 (1949). 58-79.