My reading chair faces my bookshelves, and I see them every time I look up from the page. When I say that I see them, I speak metaphorically, of course, for how often do we really see what we look at day in and day out? In the case of my bookshelves, in fact, I tend to see the books and not the shelves. If I think consciously about it and refocus my eyes -- the way I must do when viewing optical illusions, to see the stairs go up instead of down or the cube recede in perspective to the right rather than to the left -- I can see the shelves, but usually only their edges and maybe the bottoms of the upper shelves, and seldom the shelves complete and the shelves alone. Even when the bookshelves are bare, I tend to see not the shelves themselves but the absence of books, for the shelves are defined by their purpose.

If the truth be told, neither do I see the books without the shelves. The bottoms of the books rest squarely on the shelves, and the rows of books are aligned against gravity. The tops of these same books present a ragged line, of course, but even this is defined by the shelf on which they rest, and is emphasized by the straight edge of the shelf above. Books and bookshelves are a technological system, each component of which influences how we view the other. Since we interact with books and bookshelves, we too become part of the system. This alters our view of it and its components and influences our very interaction with it. Such is the nature of technology and its artifacts.

An attempt to gain perspective on the bookshelf is not a simple matter. The bookshelves in my study go from floor to ceiling and nearly cover one of its walls, but because my study is not grand, I cannot easily distance mys...