When attention began to turn towards the second or New Vienna School, scholars grouped researchers together in an inclusive approach. Thus, Fritz Novotny’s work on Cezanne was included in Christopher Wood’s Vienna School Reader, even though Novotny had been a product of Strzygowski’s Institute and not (the descendent of) Riegl’s. Subsequently, his membership in the second Vienna School has been questioned. The same issue faces another student of Stzrygowsky: Otto Demus. Nevertheless, in the following I will emphasise Demus’s academic socialisation after completing his university training, whereupon he actually did teach at the University of Vienna with Pächt. By the 1960s, the ‘two Ottos’ of course would become famous for having offered one of the most formidable medieval art programmes in the world.

As I will argue, Demus’s work fits quite well with the second Viennese school to the degree that his work is focused on an understanding of the work of art or monument as a functional whole. Parts and their relationship are understood, or in the case of a lost work, intuited by way of reconstruction. In addition, technical knowledge is used in order to judge initial states of objects so that the universal working of perception will be accurate based on these same givens.

I propose to explain Demus’s methodology through his most famous contribution: an exegesis of the structure and function of Byzantine mosaics. I will show that his approach, which has been linked to Riegl in a casual way, can be aligned in a more rigorous way. After reviewing Demus’s career, I will pass on to his important interpretation of Byzantine mosaic decoration in terms of negative perspective and the icon in space. These considerations challenge traditional notions of the self-sufficient image and mark the passage of the image as space. If Wilde had placed the image into its relational context, Demus instead marked the movement of figure and ground into new spatial configurations.