Theory of e+e- collisions at very high energy

In these lectures, the authors reviews the array of new phenomena which might be discovered in electron-positron reactions conducted at energies well above the Z0. Before beginning a discussion of what new phenomena might be found, or how they might be uncovered, the authors addresses the question of why such a program of research is important. He argues the question of what we should be looking for, and what discoveries will be the most illuminating, as we search for the next layer of fundamental physics. With this background, then contributions that the study of electron-positron collisions at high energy can make in this search can be discussed in some detail. 61 refs., 48 figs., 8 tabs