The best analogy I know for Transubstantiation – the conversion, after consecration, of the substance of bread and wine into the body and blood of Christ – is the phenomenon of “Magic Eye” images. These are glossy, colourful, two-dimensional pictures of what appear to be a series of wavy lines or patterns. For the viewer to get the “magic” effect, they should gaze upon the picture for some time, allowing the eyes to relax. At first there is a moment of dizziness as the stereoscopic functions of the brain kick in, trying to make sense of the two-dimensional surface, then, sometimes helped by the viewer moving the picture towards, or away from, the eyes, suddenly a three dimensional image is apparent. It has no necessary relationship at all to the content of the wavy lines or patterns. Indeed the wavy patterns simply yield and become the contours of, for instance, three dolphins leaping out of the water.