The four basic chapters of this story, based on the four generations of media, must be supplemented by three interspersed chapters about the assimilation of each generation of media and the accommodation of society to it. The generations are no more addative than the properties of water are the sum of the properties of oxygen and of hydrogen. The assimilation of each shift is like a vigorous shake of a kaliedoscope creating an entirely new pattern.

      The Toronto School of Media Studies is best at telling the complex story of those shifts. This school seeks to understand what's happening rather than to pronounce on whether it should be happening. The history of media, presented in terms of four generations in Chapters 2, 4, 6, 8, will thus be augmented by theoretical interludes in Chapters 3, 5, 7 containing interpretations from the point of view of the Toronto School.

      We are currently experiencing a paradigmatic shift in the structure of media with the introduction of the fourth generation. Some perspective on this shift can be gained by examining the first and second shifts with the introduction of the second and third generations of media. Those three shifts are discussed, respectively in Chapter 3 (Shift 1 - Assimilation of Second Generation), Chapter 5 (Shift 2 - Assimilation of Third Generation), and Chapter 7 (Shift 3 - Assimilation of Fourth Generation). We are too close to this current shift to see it clearly. The ubiquitous is paradoxically elusive. The fish will be the last to discover water. Perhaps by stepping back and looking at the big picture, we can see this third shift more clearly by analogy with the first and second shifts. This long view will help us not only to better understand the present but to better project into the future.