O Traço Divino - a geometria como instrumento de sacralização do espaço na igreja de Santa Maria Maior

Abstract

The aim of this work is to clarify the metaphysical implications of the use of geometry in sacred architecture, both in general and in the particular case of the church of Santa Maria Maior, Lisbon Cathedral. It begins with a research on the connections between geometry, architecture and the sacred, in order to show in what ways sacred architecture and sacred geometry come together in a scheme which regulates the physical, architectural form according to metaphysical principles. It is followed by a brief account of the cathedral's history that will inform its geometrical analysis. Knowing its physical evolution and the historical context of the main construction phases will help evaluating the validity of the analysis' results. The geometrical analysis shows two very convincing geometric schemes: one for the Romanesque church and another for the gothic ambulatory. The Romanesque scheme is based on the ad quadratum development of a square with a side of 7,7m centred on the crossing. The gothic work is defined by a scheme of inscribed heptagrams traced around the main chapel's 7-sided apse. The metaphysical value of the first scheme is the underlying reflection on the foundation of the World, which is symbolically repeated in the foundation of the church. The value of the second scheme is not so clear to read, but it may be related to the incredible symbolic power of the number Seven.