The invention of linear perspective, credited to Filippo Brunelleschi and the artists of the Florentine Renaissance, has long been presented as one of the great accomplishments of western art. According to the conventional wisdom, this discovery marks the beginning of a mature art of painting, an art of painting that shows things as they really are, as opposed to the primitive traditions that had lasted through the Middle Ages.
We are so used to linear perspective that we unthinkingly identify it with realism; to modern eyes, a "realistic" painting is one painted in linear perspective. Some may argue that the resemblance of such a painting to a photograph is proof of its realism. But this begs the question; had we not already been accustomed to consider perspectival painting the standard of realism, we might never have accepted photography as realistic either. I can imagine an ancient Egyptian sage inventing the camera, and upon discovering that it did not always show the human figure in profile concluding that it did not work very well.
A perspectival painting is, in many ways, not realistic at all. Some of these ways are obvious. The subjects do not move. Neither can the person looking at the painting move, or the failure of objects within the painting to move in relation to each other will reveal its artifice. The frame, usually rectangular, is unlike the actual periphery of our vision. And a perspectival painting is the view of a Cyclops; images do not double into two transparent parts when the two eyes focus on something nearer or farther away. Nor do they blur or sharpen dramatically; in reality, an object inches from the eyes and an object ten feet away cannot be seen in detail at the same time. A perspectival painting accurately presents what a man will see if he looks through a frame, with one eye closed, not moving, at something that does not move and that is far enough away for his eyes to focus on it in its entirety. Not surprisingly, the trick box that Filippo Brunelleschi invented to demonstrate his discovery of the technique created all of these conditions!
But there are more important ways in which a perspectival painting is unrealistic; it presents things as they are seen to be, rather than as they are known to be. It does not accommodate the vision of the mind's eye. Children draw in the same manner as cultures that have not adopted perspective in their art; they draw what is important. If they know of something present on the other side of a wall, or beyond the scope of their vision, they will draw it anyway if it is necessary to what they seek to communicate on paper. And its relative importance to that message will determine its size and placement in the drawing. This is the natural manner of composition in human artistry, whereas perspective is something that must be learned.
In the mediaeval mind, hierarchy, rhythm and number are the fundamental laws of the universe. Art was painted and drawn and woven in the same manner that literature was written and the natural world was observed; symbolism was the animating principle. The literal is only one of four senses of reality; the allegorical, tropological and anagogical senses are equally real, and equally necessary to depict.
In a mediaeval painting of the Last Judgment, Christ is flanked by the Blessed Virgin and the Baptist; apostles and martyrs surround them, pleading the cause of mankind. Angels carry the instruments of the Passion; personifications or symbols of Justice and Mercy may be present. The dead rise from their tombs; St. Michael weighs them in a scale; demons drag some of them to the gaping mouth of Hell; angels lead some of them to the gate of Heaven.
The selection and arrangement of these elements must be theologically correct; Christ must be in the center, the blessed on His right, the damned on His left, the saints in proper order according to their dignity. Fitting such a composition into the "realistic" space of linear perspective, where all bodies are the same size and all lines converge to points on the horizon, is nearly impossible. Not even the genius of Jan van Eyck could manage it without cheating.
Mediaeval art communicated not only through symbolism, but also through narrative. It told stories from the Holy Scriptures, from the lives of the saints, from secular history and from everyday life. The narrative art of this time in tapestry, glass and large-scale painting must be distinguished in an important way from manuscript illumination, and from modern illustration. An illustration is a picture that supports a text; a man reads what he should see, and looks at the picture already able to identify the characters and the place and the situation. But a mediaeval mural has no supporting text; or if it does, the artist cannot rely on it to explain the content of the picture because most people seeing it are unlettered.
This really is significant; such a work of art does not support a story; it is the story. It needs to tell the entire thing by itself. Enough of the time and of the place, of the characters and their motives and their doings must be shown for a man to understand the narrative just by looking at the picture. This demands that a great many details be visible; every figure acts or reacts, every important prop is shown. Such a work of art will not resemble a photograph, but it is no less truthful; were a mediaeval man handed a photograph, capturing a single viewpoint at a single moment, he would probably scratch his head and wonder what was supposed to be happening in the story.
A great amount of information must to be included in a mediaeval picture to communicate the intended symbolism or narrative. Perspective is actually an hindrance to this. In perspectival space, most activity occurs within a squat region between ground level and six feet above ground level. The result is that the figures are all standing in front of each other. Mediaeval artists often lifted the plane of the earth, so that figures in the background are seen above figures in the foreground, not completely blocked by them.
This art fills all of its given space, wasting none of it on empty sky. The art critical term for this is horror vacui, the fear of the void. It is a nearly universal artistic conviction; only in the far east and in modern times have artists valued blank space. Only Buddhists and Nihilists are interested in nothingness.
The challenge of empty sky especially affects ecclesiastical art. Verticality is one of the defining traits of an architecture consecrated to divine worship; it is most exaggerated in a Gothic church. The altars, the columns, the stained glass windows and the wall spaces between them are tall and narrow; they do not welcome linear perspective, because it would assign most of their space to empty sky.
Later artists who did use linear perspective were faced with this same challenge; their churches were not as pointed as the 13th century cathedral, but they were still taller than wide. They did not answer the challenge very well; the Renaissance artists filled the sky with towering classical ruins and the Baroque artists filled it with clouds and cherubs. Such unimaginative filler has been clogging sacred art for centuries.
For more than five hundred years, the art of the Middle Ages has been slandered as primitive and unrealistic. Art historians have disdained mediaeval artists for not developing linear perspective. But there is a good reason why they did not develop linear perspective; they had no need for it. The two most important purposes of their art - symbolism and narrative - were more easily fulfilled without it. It simply was not a very smart way to paint or draw or weave.
