“If you can think of life, for a moment, as a large house with a nursery, living and dining rooms, bedrooms, study, and so forth, all unfamiliar and bright, the chapters which follow are, in a way, like looking through the windows of this house. Certain occupants will be glimpsed only briefly. Visitors come and go. At some windows you may wish to stay longer, but alas. As with any house, all within cannot be seen.”