the extensions of man—the technological simulation of 
consciousness, when the creative process of knowing will be 
collectively and corporately extended to the whole of human 
society, much as we have already extended our senses and our 
nerves by the various media. Whether the extension of 
consciousness, so long sought by advertisers for specific 
products, will be “a good thing” is a question that admits of a 
wide solution. There is little possibility of answering such 
questions about the extensions of man without considering all 
of them together. Any extension, whether of skin, hand, or 
foot, affects the whole psychic and social complex.

     Some of the principal extensions, together with some of 
their psychic and social consequences, are studied in this book. 
Just how little consideration has been given to such matters in 
the past can be gathered from the consternation of one of the