The subject ofthis monograph is a recently developed (non-linear) potential theory which is particularly suitable for multidimensional complex analysis. To provide a framework for the approach adopted in this book, we shall first make a few comments concerning convex and subharmonic functions. One of many characterizations of convex functions is the following. Let I C R be an open interval, and let v be a real-valued function defined on I. Then v is convex if and only if the set of points lying on and above the graph of v is convex; that is, any two points of the set