As the sunset contains both day and night, and the waves, foam and water, two disparate elements of nature inseparably constitute a book. A book is a thing among things, an object among the objects that coexist in three dimensions, but it is also a symbol like an algebra equation or an abstract idea. We may compare it to a chess game: a checkered black and white board with pieces and an almost infinite number of possible moves. The analogy to musical instruments is also clear, such as the harp Bécquer glimpsed in the corner of a drawing room and whose silent world of sound he compared with a sleeping bird. Such images are mere approximations or shadows; a book is much more complex. Written symbols are mirrors of oral symbols, which in turn convey abstractions, dreams, or memories. Perhaps it will suffice to say that a book, like its writer, is made of body and soul. Hence the manifold delight it gives us, the joys of sight, touch, and intelligence.