Orient-Occident proposes to trace the history of Western art (and of neighboring cultures historically tied to it) in relation to its philosophical/ theological background, beginning with the Egyptian Book of the Dead through Platonism, Christianity, to Islam and the Renaissance.
Of particular interest is a chapter on the Neoplatonic influences that entered into the conception of Agia Sophia. The structure of the building, famously described by Procopius, incorporates various geometric forms (square, half-circle, triangle) united under the full circle, the most perfect of all forms. The unity of the forms is a concept developped by Neoplatonist philosophy and especially by Proclus in his Comments on Euclid. Interestingly, the two architects of Agia Sophia, Anthemius of Tralles and Isidorus of Miletus, were precisely also able mathematicians, and therefore were almost certainly familiar with Proclus’ work. It would be normal then that they incorporated these concepts in their architectural works.