Perhaps the first departure from the purely didactic argument may be found in Gregory of Nyssa, who speaks of a picture of the Sacrifice of Isaac as a source of deep emotional experience. (Oratio de deitate filii et spiritus sancti [PG 46, vol. 527 C) A more decisive step forward was taken when contemplation of an image was claimed not merely to benefit a beholder’s religious education or stimulate his emotion, but to constitute some sort of channel enabling him to approach the Deity. This line of reasoning, in which the image becomes a means of visualizing the invisible or of conveying to it love or respect, had been elaborated in various forms by apologists of pagan image worship. It was, as we have seen, a standard concept for defining the role of the ruler portrait, and in that sphere it was adopted by Christian writers as early as the fourth century. In the first half of the fifth century it was applied to a religious image by Phiostorgius. We have spoken previously of his account of the statue of Christ at Paneas, in which he describes what he considers the proper demeanor in front of a religious image. The apologetic nature of his remarks is self-evident. He writes with an eye on critics inside or outside the Church when he deprecates all thought of worship or proskynesis, “since it is not permitted to prostrate oneself before bronze or other matter.” Nevertheless he sees in a joyful approach and gaze on the image a way of demonstrating one’s love for its archetype. In a somewhat colorless formula worked out at a time when practice was already going well beyond that Philostorgius considered proper boundaries.
The idea that the image may serve the faithful as a channel of communication with the Deity received a powerful impetus toward the end of the fifth century through the anagogical concepts introduced into Christian thought by Pseudo-Dionysius. These concepts formed part of that great Neoplatonic mystic’s interpretation of the physical and intelligible worlds as superimposed hierarchies. “The essence and others which are above us . . . are incorporeal and their hierarchy is of the intellect and transcends our world. Our human hierarchy, on the contrary, we see filled with the multiplicity of visible symbols, through which we are led up hierarchically and according to our capacity to the unified deification, to God and divine virtue. They, as is meet to them, comprehend as pure intellects. We, however, are led up, as far as possible, through visible images to contemplation of the divine.” (De ecclesiastica hierarchia, I, 2 [PG 3, vol. 373 AB) (Ernst Kitzinger, “The Cult of Images in the Age before Iconoclasm,” Dumbarton Oaks Papers 8 [1954]: 137-8)
. . . in the first half of the sixth century, we encounter the first hint in literature of proskynesis being practiced before images in churches. It appears to have been contained in an inquiry received by Bishop Hypatius of Ephesus from one of his suffragans, Julian of Atamytion. We know of this inquiry only from Hypatius’ reply, a highly important document in the history of Christian theory concerning images . . . judging by this letter, Julian, though worried about the propriety of sculpture in churches, in view of the Old Testament prohibition of graven image,s took no exception to painting and even tolerated their worship in the form of proskynesis. (Ernst Kitzinger, “The Cult of Images in the Age before Iconoclasm,” Dumbarton Oaks Papers 8 [1954]: 94)