Sistine Chapel ceiling identity of the figures in the lunettes and spandrels, continue to defy interpretation. Modern scholars have sought, as yet unsuccessfully, to determine a written source of the theological program of the ceiling and have questioned whether or not it was entirely devised by the artist himself, who was both an avid reader of the Bible and a genius. Also of interest to some modern scholars is the question of how Michelangelo's own spiritual and psychological state is reflected in the iconography and the expression of the ceiling. One such speculation is that Michelangelo was tormented by conflict between homosexual desires
Sistine Chapel congregations. These included the Christmas Day and Easter masses, at which the Pope himself was the celebrant. The other 27 masses could be held in a smaller, less public space, for which the "Cappella Maggiore" was used before it was rebuilt on the same site as the Sistine Chapel. The "Cappella Maggiore" derived its name, the Greater Chapel, from the fact that there was another chapel also in use by the Pope and his retinue for daily worship. At the time of Pope Sixtus IV, this was the Chapel of Pope Nicholas V, which had been decorated by Fra Angelico.