As human beings, we strive to understand the world around us. The path to understanding, however, is rarely walked alone; we walk the path with others. We understand more together, by joining forces, than we would understand alone. Moreover, when we understand something and come to see things clearly, it is probably because someone else has taught us, enlightened us, shared his or her perspective with us, or shaped our environment so that our attempts to make sense of the world were likely to succeed. This book is a journey of in-depth exploration into the social dimensions of understanding. This first chapter gives an overview of the structure of the book.