"Know thyself," is inscribed in stone at the entrance to the Temple of Apollo at Delphi. For Socrates, "The unexamined life is not worth living." Plato likens us to one spending life chained in a dark cave. It seems that some people, living two or three thousand years ago, had discovered something. They had opened the door to something they regarded as having the highest value some insight that makes life worth living. What is it they came to know? That is the sole subject of this book. What they knew, and, more importantly, how we can come to know what is so enriching. Some insight to start the examined life, some insight that makes life worth living...that allows us to peer out of the dark cave. This is not some secret knowledge passed down through the ages. It appears in the writing of many people who value the examined life. This topic is not touched on in high school or university. I have never seen it broadcast on television, nor explored in any movie. I feel strongly that an entire book is needed to help absorb this key topic...the key to the door of perception.