| America | Tech | Opinion | Culture | Charts |Today I’m delighted to welcome Andrew McLuhan to the a16z newsletter as a guest author. Andrew is Marshall McLuhan’s grandson, and has a fascinating story to share that’s equal parts family history and media theory. For more on New Media theory, you can catch up on yesterday’s piece here, and be sure to follow Andrew on X. -ADAre there any general principles of technology, attributes and effects common to all products of human innovation, to all of these artificial extensions of ourselves? These were among questions Marshall McLuhan and his son Eric McLuhan set out to find and answer in the early 1970s.The ‘tetrad’ or ‘laws of media:’enhances: awareness of inclusive, structural processobsolesces: dominance of logical methodreverses into: technology (hardware) becomes softwareretrieves: metaphor, logos‘Laws of Media: The New Science’ (Marshall and Eric McLuhan, 1988)McLuhan Sr. had been approached by publisher McGraw-Hill to do a 10th anniversary edition of his best-selling 1964 work ‘Understanding Media: The Extensions of Man.’ I think they wanted a new introduction, maybe an extra chapter or two to examine technologies which had come on the scene in the years since Understanding Media. And at first, I think this is what Marshall and Eric set their sights on, as notes in their copies of Understanding Media suggest. They referred to this project as UMR, or ‘Understanding Media Revised,’ and even at that point it was more than the publishers had asked for. It became much more.McLuhan ignored or defied the apparent rule that no book can be more than 10% new, as he pointed out in the 1964 introduction to Understanding Media:“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 editors of this book. He noted in dismay that “seventy-fi