Occasion and Method
In the beginning I spoke in few words; let me now speak more fully. For errors that have been embraced with enthusiasm and spread about with authority require a special and thorough refutation, lest silence be taken for consent and the injury grow. I have been asked, or rather commanded, by those who love the truth, to set out fully and systematically the defense of the holy images; and I do so gladly, knowing that in this defense I am defending not my own opinion but the tradition of the whole Church, confirmed by the testimony of Scripture, of the holy Fathers, and of the Ecumenical Councils. Let no one think that in venerating the images I am worshipping wood and paint. I am venerating what is depicted in and through the wood and paint; and the honor passes through the image to the one depicted, as even the pagan Basil of the Schools acknowledged when he wrote that the image and the archetype are not the same, and that the honor given to the image is transferred to the original.
Before we can speak accurately about the veneration of the holy images, we must distinguish carefully among the different things that are called images, for many things are called by that name and they differ fundamentally in nature, in purpose, and in the kind of honor appropriate to them. The first and most essential image is the natural image: the Son, who is the natural and living Image of the Father, bearing in Himself the complete nature, the perfect will, and the infinite wisdom and power of the Father, differing from the Father only in that He is begotten, not unbegotten, while sharing with the Father the same divine nature. This is the image in the fullest and most proper sense: the Image who is not made but born, who proceeds from the same substance as the One He images. All other images are images in a derived and secondary sense.
The second kind of image is God's foreknowledge of all things: the eternal thoughts in the divine mind through which God knew from before the foundation of the world everything that would be, each thing in its particular nature and history. These thoughts are images of what would come to be, not made by an external artisan but subsisting from eternity in the divine mind. In this sense, everything that has ever existed was first an image in the thought of God before it was a reality in time. The third kind of image is the human being, who is made in the image of God: rational, free, and immortal, bearing in the constitution of his nature a likeness to his Maker. This is an image not made by human hands but by the divine creative act, and the honor due to this image -- which is why the murder of a man is forbidden, since it destroys the image of God -- is far greater than the honor due to any image made by human hands.
The fourth kind of image is the artificial image: the representation of a person or scene made by a human craftsman in paint or mosaic or stone or wood. It is with this kind of image that the present controversy is concerned. These images are not the same as their originals; the icon of Christ is not Christ; the icon of the Theotokos is not the Theotokos. But they are not unrelated to their originals either; they are depictions of real persons, and the honor given to a depiction is naturally referred to the one depicted. This is why we give honor to the icons of Christ and the saints: not because we worship the matter of which they are made, but because we venerate the persons whom they represent, and the veneration passes through the image to the person.
The fifth kind of image is the commemorative image: the written record, the historical narrative, the monument, the story. When the Scriptures record the acts of the patriarchs and the prophets; when the historian records the deeds of kings and generals; when the hagiographer records the life of a saint -- these are images of those persons in the medium of language. No one objects to the commemoration of holy persons in words. Why should the commemoration of holy persons in paint be different in principle? Both are records; both preserve the memory; both honor the one commemorated; both invite those who see or hear to imitate what they admire.
With these distinctions in hand, we can address the objection that images are forbidden by the Law of Moses. God said to Moses on Sinai: You shall not make for yourself a carved image, or any likeness of anything that is in heaven above or on the earth beneath or in the water under the earth. The iconoclasts say this prohibition is universal and permanent: no images of any kind, in any context, for any purpose. But we say: this is not how the prohibition was understood by Moses himself, who immediately after receiving it commanded the making of the golden Cherubim over the Ark of the Covenant, and the making of golden pomegranates for the priestly vestments, and the making of the brazen serpent on a pole as a means of healing for the people. The prohibition is against idolatry -- against the making of images to be worshipped as gods. It is not a prohibition against images as such.