" The exciting thing about mathematics and science and music and literature is what they can tell us about the workings of the human mind. For these disciplines are literally models (extensions) of at least certain parts of the mind. Just as the knife cuts but does not chew, while the lens does only a portion of what the eye can do, extensions are reductionist in their capability. No matter how hard it tries, the human race can never fully replace what was left out of extensions in the first place. Also, it is just as important to know what is left out of a given extension system as it is to know what the system will do. Yet the extension-omissions side is frequently overlooked. "

― Edward T. Hall