The practice of making and honouring holy images, icons, in Christianity, is preserved from ancient times until the present in the Orthodox Church. During the last decades icons have become more and more popular in other Christian confessions as well. They are popular as objects of Christian art, the theology of icons has, however, not been fully absorbed by other traditions. I suppose the term theology of the icon may sound rather strange to some readers. Now, how do one think theologically about icons, and how are images philosophically justified? These are questions I would like to treat in this article.