Lying quiet in the shadow of the Hellenistic flourish a few centuries before Christ, when Rome appropriated the architecture of the Greek and Etruscan colonies, it was selective in its borrowings and adapted geometry to a new use: the active experience of space through the novelty of the arch.Then there was the dome, and all of the sudden Imperial Rome was heralding its grandeur through large scale, massive, state funded architecture.
Architecturally, the Renaissance was a looking back upon and a scrutinizing of Classical antiquity, with the realization that they had gotten something right.
When they looked back at Rome (or in some cases, what they thought was Rome) they saw Nero’s Golden Palace, the Pantheon, S. Constanza, the Florentine Baptistery, and most importantly they saw Vitruvius. What the Renaissance thinkers noticed was a gradual and deliberate preoccupation with central-domed structures.
Leon Battista Alberti, a Renaissance scholar and a Humanist, defined the ideal church in his treatise as noble and beautiful, one which stirs sublimity, quickens piety, and produces singleness pleasing to God. Alberti said that beauty consists in “a rational integration of the proportions of all the parts where nothing can be added or taken away with out destroying the harmony of the whole.” No form more completely met this demand than the circle.
Vitruvius set the standard for the Humanist ideal with his well-proportioned man, which Leonardo da Vinci later sketched in 1485. This became the impulse of the intellectual move towards the new architecture. With the translation of his architectural treatise in 1511 from Latin to the common language, the new banner of this renaissance was unfurled. Vitruvius preached that the proportions of a temple should magnify the proportions of man. He attempted to prove the supremacy of the human form by showing how, when extended with outstretched members, it fits perfectly within the purest geometries: the circle and square.
The goal of the Renaissance centrally-planned church was to reveal man’s true dimensions to the world, that man was worth something in himself. It was an intellectual awakening in which man stopped looking up and started looking around. The Medieval preoccupation with God fractured under the new philosophical strain and the resulting schism in society remains large today.