In the field of architecture the attractiveness of the new Byzantine style in the eyes of a Justinian and an Anthemius was probably due to the very fact that this Byzantine style presented the greatest contrast to the Hellenic style that was well conceivable. The Hellenic architecture was a structure of straight lines and flat surfaces meeting at right-angles; the Byzantine architecture was a structure of curves and cupolas. The Hellenic temple looked outwards towards an assembly in the open air; the Byzantine church looked inwards towards a congregation in the interior. The Haghia Sophia was the monumental protest of a generation which could no longer find inspiration in the Parthenon or in any of those things for which the Parthenon stood. In building an Haghia Sophia instead of a Parthenon, Anthemius was doing, in essence, what a Synesius or a Sidonius Apollinaris was doing when he became a bishop instead of remaining just a cultivated country gentleman, or an Augustine when he became a bishop instead of remaining just a professor of rhetoric, or an Ambrose or a Gregory the Great when he became a bishop instead of remaining just an Imperial official. In each of these cases a creative personality was breaking his way out of his hereditary social framework, in which his creative powers had been baulked, and was setting himself into a new framework in which these powers were offered an outlet.
Reluctant churchmen in late antiquity (old post).
A Study of History, Vol IV, OUP, 1939