The unfinished temple at Segesta

The Doric temple is one of the great archetypes of architectural history. Not only was it one of the ancient Greeks' most celebrated achievements, it was also the ultimate reference for other typologies: propylaea, stoas, and miscellaneous civic buildings. The 5th century temple form in particular has been a highly influential source for the later practice of classical architecture - few major European and North American cities lack a church, town hall, museum or bank directly inspired by the Parthenon or the Hephaisteion. So it seems little short of astonishing that the design of the ancient Doric temple remains a largely unresolved question, especially given the considerable scholarly effort dedicated to its investigation.

This lack of resolution reflects to some extent lapses of regularity and symmetry in Doric temple plans, lapses which Vitruvius called "the faults and incongruities" that flowed from the notorious problem associated with the configuration of the peristyle and its frieze at the corner. This problem was also compounded in the archaic period by the prevailing reliance on rules of thumb and a successive approach towards making individual decisions. But by the second quarter of the fifth century architects had acquired a greater control over the design process, becoming able to instill their projects with improved coherence and precision, as well as neater proportions. From then on column spacings (excepting the corner bays) tend to be both more regular and more clearly related to other major compositional elements. The most striking manifestation of this shift is the widespread adoption of a 2:3 ratio between the widths of triglyphs and metopes, a relationship that automatically generated column spacings equivalent to 5 triglyph widths. The main contribution of this article is show that the triglyph width was much more than just one consideration out of many; it constituted the very lynchpin of a fully-fledged modular design method.

While my proposals are chiefly based on an analysis of the facades of ten relatively well preserved hexastyle temples, complementary observations are also telling. By couching design in terms of the triglyph width, the very dimension that lay at the root of the corner problem, the modular approach brought tangible advantages for designers; it redeemed a degree of numerical harmony that would otherwise not be present; it helps explain both the consistency of temple facades and their 'evolution' over time. Significantly, such an interpretation also tallies with the evidence of Vitruvius, our sole ancient authority. Not only did Vitruvius describe Doric design in modular terms, but he also chose a module equal to the triglyph width. In the past scholars have tended either to trace Vitruvius' account only as far back as the Hellenistic period, or alternatively to doubt its legitimacy altogether. Yet it now emerges that Vitruvius perpetuated principles and practices that went well back into the 5th century.