Structure

The book is divided into five parts, each part headed with a title that suggests the overall focus of the chapters each part contains. Within each part there is a collection of chapters, each of which has both a title of its own that suggests the specific focus of that chapter, and a subtitle. That subtitle serves as both a summary of that chapter’s content and as one of the twenty-one lessons of the book’s title.

For example, Part I is titled “The Technological Challenge,” and focuses on different aspects of technology that the author foresees as shaping and challenging human existence in the twenty-first century. The first chapter of Part I is titled “Disillusionment,” and considers some of the different, difficult transitional truths faced by the human race in the early decades of the twenty-first century, truths that the author contends are in fact...