what he saw as a co-existence of the spiritual and material worlds. The iconography was embedded in the work unobtrusively; typically the references comprised small but key background details. The embedded symbols were meant to meld into the scenes and were "a deliberate strategy to create an experience of spiritual revelation". Van Eyck's religious paintings in particular "always present the spectator with a transfigured view of visible reality". To him the day-to-day is harmoniously steeped in symbolism, such that, according to Harbison, "descriptive data were rearranged ... so that they illustrated not earthly existence but what he considered supernatural truth." This blend of the earthly and heavenly evidences van Eyck's belief that the "essential truth of Christian doctrine" can be found in "the marriage of secular and sacred worlds, of reality and symbol". He depicts overly large Madonnas, whose unrealistic size shows the separation between the heavenly from earthly, but placed them in everyday settings such as churches, domestic chambers or seated with court officials. Yet the earthly churches are heavily decorated with heavenly symbols. A heavenly throne is clearly represented in some domestic chambers (for example in the Lucca Madonna). More difficult to discern are the settings for paintings such as Madonna of Chancellor Rolin, where the location is a fusion of the earthly and celestial. Van Eyck's iconography is often so densely and intricately layered that a work has to be viewed multiple times before even the most obvious meaning of an element is apparent. The symbols were often subtly woven into the paintings so that they only became apparent after close and repeated viewing, while much of the iconography reflects the idea that, according to John Ward, there is a "promised passage from sin and death to salvation and rebirth". Other artists employed symbolism in a more prosaic manner, despite van Eyck's great influence on both his contemporaries and later artists. Campin showed a clear separation between spiritual and earthly realms; unlike van Eyck, he did not employ a programme of concealed symbolism. Campin's symbols do not alter the sense of the real; in his paintings a domestic scene is no more complicated than a one showing religious iconography, but one the viewer would recognise and understand. Van der Weyden's symbolism was far more nuanced than Campin's but not as dense as van Eyck's. According to Harbison, van der Weyden incorporated his symbols so carefully, and in