Wittkower's historical study which is examined critically in the following, is a good example. Its conclusion is that the Renaissance’s attitude to architecture was intrinsically rationalistic, and dominantly geometrical and mathematical. This exaggerated ‘pars pro toto’ generalization produced an utterly distorted image that contributed essentially to the development of modern architectural rationalism.
Wittkower's illegitimate generalization is here being contrasted with a quite different method based on the evolution of architecture and space and on formal comparison. This yields a new insight: the architecture of the Middle Ages and the Renaissance represent an entire world view that can still be understood today. It perceives objects in categorial opposition, with the intention of creating harmonious units. If this world view expresses its insights through the harmonious relations of bright AND dark, of above AND below, of the spiritual AND the material, then the art historian’s incompetence would be sufficiently established. To put it more crudely: aesthetics only talks about black OR white, above OR below, the material OR the spiritual. The "theory of relativity" in art, its essence, is necessarily ignored by him.
Evidently, our method will differ from that of the art historian. It operates within a wide anthropological perspective. Insights thus gained lead to the perception of new sources or to a reinterpretation of known sources. Crucial are the architectural sources themselves, not their written history. This approach uncovers amazing continuities of tectonic, or iconic, orders. This method, 'structural ergology', was outlined in detail in the preceding text of this book.
The problem with this representation lies in the evaluation which it implies. Strict historical method, to which Wittkower attaches so much importance, owes its - seeming - precision to a complete neglect of the concrete prerequisites, namely the architecture of the historical background. The idealized historical spirit entirely supplants the expressive language of architectural tradition. Inasmuch as Wittkower appeals to classical historical tradition, he simultaneously dismisses the essential element, namely architectural continuity. What he then considers to be the theme of architectural creativity, turns out to be a monstrous product of the historical spirit. Thus Wittkower finds no difficulty in presenting us with an image of Renaissance architecture as a fully rationalized and mathematically determined art. <4>
Matters are quite different when one tries to understand Renaissance architecture and its relationship to its predecessors in terms of the architectural tradition itself and its historical environment: The elements discussed by Wittkower are already palpable in medieval architecture. Though interpreted differently, 'harmonious proportioning' plays a central part in medieval times and the most important element in Renaissance circular–plan building, the dome, is already highly developed in the Byzantine cultural area. In this sense, critical of Wittkower, we present and discuss in the following architectural representations in medieval book illustrations.
Generally, the book illuminations’ basic function is considered to be ornamental: they are seen as decoration, at a time when books were still written by hand. But the static composition (centralized figures), the close relation to tectonic elements, and particularly the rich plant and basketry motifs are more than decorative attributes. They evidently functioned as illustrations to the meaning of the abstract texts. Consequently, they can be "read". <5>
In this sense, medieval book illuminations are a very valuable source for the history of medieval architectural thought, particularly with respect to sacred edifices. Tectonic elements are not subject to constructive conditions; they will never have to be built. The support of loads only plays an insignificant part. Moreover, the designs are made by architectonic laymen. They are meant to express an idea, rather than a purpose. These more or less imaginary structures reveal to us the concepts behind medieval architecture far better than any existing building could do.
All pictures are characterized by a more or less explicit tectonic arrangement. Two or more columns with capitals showing plants, basketry, or geometric ornaments define a rectangular lower field. Above the horizontal line defined by the top of the capitals one or more arches spring up, defining part or the whole of one or several semicircles. In general, the arch (or the arches) are ornamentally or otherwise differentiated from the pillars, thus emphasizing the bipartition of the whole picture.
But such obvious meanings should not mislead us into simply explaining illuminations as mere illustrations of biblical history. From a formal point of view it is impossible to explain why these representations persistently rely on tectonics, why they are so closely connected with buildings, nor why particular ornaments are used. Obviously there is a deeper meaning, which is expressed in bipartition or in the unification of two different media (limited/unlimited, below/above) providing the picture with existential meaning: the Evangelists gain significance because they are depicted in a polar relation of the sacred and the profane, the imaginary and the real, of heaven and earth.
Relying on this primary meaning of the term ‘proportion’ as "something defined with a complementary protruding part’ (pro-portion) this can be applied to medieval book illuminations in a very concrete and nonmathematical way.
Evidently the original meaning of the term is still present in medieval illuminations. Above the horizontal line or level defined by the upper end of the capitals, the arch projects in a dynamic curve, as an element quite different from the lower rectangular field. The tympanum has no support whatever in its middle section. There is no contact with the ground between the capitals. The arch spans an empty space. Thus, to a pre-engineering constructor it projects, quite irrationally, over the lower part. This is pro-portio in the Latin sense. 'Portion' is the part defined by the columns, 'pro-' the section or imaginary space defined by the arch. The sections or spaces defined by the two elements are not homogenous in the sense of our modern understanding of space, the lower part being related to the physically empirical, the upper to the spiritual imaginary world. In the upper section there are figures from religious tradition and fable, winged animals and humans, the providing hand of God the Father and other historically postulated metaphysical expressions. In contrast though, the Evangelists in the lower part, idealized in their function as sacred figures, are palpable, with their names and historical existence known. Other examples show natural and artificial objects and, particularly, depictions of architecture. Concluding, we find two types of space - or human relations to the world - portrayed in the representations of tectonic structures: an empirically realistic and an idealistically imaginary world, obviously intended to depict an interrelated unity of the two parts.
With relation to Wittkower, the crucial point here is that the term proportion now gains a philosophical dimension. It represents much more than just mathematical relations, it is closely intermingled with spatial, material, constructive qualities, related to the social and the temporal. And it brings two basic aspects of human cognition into a harmonious relation: the empirically real and the ideal, imaginary world.
To put it another way: our representations are likewise - with the analogies they suggest - models of the world, prototypes for whatever exists in this world. This is no speculation. Medieval pictorial and sculptural art supplies countless indications proving this assumption to be valid.<6> The dome and the vault with their substructure, portals, and windows of Roman, Romanesque, <7> and medieval architecture all represent in some way or other, 'the world'. They are implantations into the chaos of a nonacculturated environment of contradictive forces.
The human world as an implantation into the chaos of contradictive forces; the human world as a harmonious response, as art. But this would mean that each of these bipolar units (columns and arch) carried its own message. Architectural expression as a model of human existential conditions. Harmony between two opposite types of human perception of the world, between idea and reality, imagination and experience, heaven and earth. And as such it is both a part and a model of microcosmic and macrocosmic harmony, not in a symbolic but in an ontological way. We discover how medieval architecture structures the human environment through a continuous composition of portals, windows, larger sacred buildings with arches, domes, and spires, from which it eventually proceeds to the large cosmos of heaven and earth. All these elements are related to the basic model of an ontologically proportioned architectural harmony. <8>
In the following, we shall deal with a more impressive example of such an ontologically proportioned architectural model, the Hagia Sophia, the main church of the eastern Roman empire.