This experience and many others over the years have convinced me that, while the tech- nical  means  whereby  true  global  information  interchange  can  be  achieved  are  well within our grasp, there are significant anthropological obstacles. For one thing, its very challenging  to  interchange  information  about  information  interchange.  As  human beings, we pride ourselves on our ability to communicate symbolically with each other, but comparatively few of us want to understand the details of the process. Communica- tion about communication requires great precision on the part of the speaker and an unusually high level of effort on the part of the listener. I suspect that this is related to the fact that many people become uncomfortable or lost when the subject of conversa- tion is at the top of a heap of abstractions that is many layers thick. Its an effort to climb to the top, and successful climbs usually follow one or more unsuccessful attempts. When you have mastered the heap of abstractions that must be mastered in order to understand how global information interchange can be realized, the reward is very great.  The  view  from  the  top  is  magnificent.  From  a  technical  point  of  view,  the whole problem becomes simple. Very soon thereafter, however, successful climbers realize that they cant communicate with nonclimbers about their discoveries. This peculiar inability and its association with working atop a tall heap of abstractions are evocative  of  the  biblical  myth  of  the  Tower  of  Babel.  Successful  abstraction-heap climbers soon find themselves wondering why their otherwise perfectly reasonable and  intelligent  conversational  partners  cant  understand  simple,  carefully  phrased sentences that say exactly what theyre meant to say. You have now been warned. This book is about the topic maps paradigm, which itself is a reflection of a specific set of attitudes about the nature of information, communi- cation, and reality. Reading this book may be quite rewarding, but there may also be disturbing consequences. Your thinking, your communications with others, and even your grasp of reality may be affected.³ Information Is Interesting Stuff Information  is  both  more  and  less  real  than  the  material  universe.  Its  more  real because it will survive any physical change; it will outlast any physical manifestation of itself. Its less real because its ineffable. For example, you can touch a shoe, but you cant touch the notion of shoe-ness (that is, what it means to be a shoe). The notion of shoe-ness is probably eternal, but every shoe is ephemeral. 32 CHAPTER 3 A PERSPECTIVE  ON THE QUEST  FOR GLOBAL KNOWLEDGE INTERCHANGE ³The writings of Plato, the ancient Greek philosopher who pioneered many of the basic philosophical ideas, have been having similar effects on their readers for thousands of years.