The format of the book is a little unusual because I decided to use the structure of a commonplace book, in which commonplace items that one comes across in one's life are jotted down for future reference in a journal. The idea is to let the quotations set up discussions about various aspects of learning. My intent was to end up with a loosely coupled but reasonably coherent set of ideas within each chapter. This goal was pursued by seeing to it that a substantial number of quotations within a chapter are at least somewhat related. One advantage of this format is that the reader can open the...