An excerpt
From Alexander Tzonis & Liane Lefaivre,
Classical Architecture: The Poetics of Order (previous excerpts:
1,
2), chap. 2 "Genera: the elements":
Let us look at the canonical three genera [or "orders"] of classical architecture as a series for a moment. At one end, the Doric is divided into a few brief, plain members. At the other end, the Composite has so many members that they almost seem to gesticulate and intertwine. Obviously we have an increasing complexity here, an augmentation of subsections. What the Doric does with one single contour unit – for example, the one torus base – the Composite can take up to six or seven units to do through embedding and amplification. This applies to other members besides the base. The single Doric abacus, for example, is subdivided into three sections in the Ionic and into five in the Corinthian. The architrave, a single unit in the Doric, is sectioned into five units in the Ionic and into seven in the Corinthian. At each genus step more details are added into the same section; more shape events are compressed within the same stretch of space.
This brings us full circle to the point made at the beginning of this chapter. We can now elaborate further: The genera form a level of formal constraints that organize an architectural composition and complement the taxis. Although taxis governs the relation of part to whole, the genera dictate the direction, seriation, and hierarchy of the parts. Through the configuration of their profile, the genera make us understand and control space in a particular way. They have the built-in capacity to do so because they are internally organized as a string of shape contour patterns that can represent progressions and because they can be structured in terms of discrete steps and hierarchies.
It should be clear by now that the moldings – the cymatia, the bead, the fillet, the scotia, and the cavetto – or so-called ornaments of the classical genera, are not in the least "ornamental" and "decorative" in the sense of a frivolous adjunct of an almost superfluous elaboration. They are an essential structure of the classical system, vital to its poetics of order. Although the moldings affect small-scale aspects of the composition, their impact is major. They can blur distinctions and clarify them. They make terminations invisible, and they can sharply demarcate them. The ornament in classical architecture should not be confused with the ornament in classical music, synonymous with agréments or plaisanteries and mere improvisation. Neither should it be mistaken for the embellishing frills that designers increasingly applied during the nineteenth century for purposes of conspicuous consumption. The ornaments, in the sense referred to here, can make or break the coherence of a classical composition.
illustration: architectural theory from the renaissance to the present, p 443, taschen 2003
