I rank this as one of the tem best books I own.
"The text owes much to Marshall McLuhan who, in fact, co-authored portions of an earlier version." This quote comes from the opening page - before the Foreword. It is well documented that McLuhan had trouble with writing and co-authors. Carpenter was an early collaborator from the Dew Line on and I think was able to interpret McLuhan the best.
Or was it the other way around? I hate to say this, but this may be the easiest read of McLuhan's ideas. It becomes hard to distinguish Carpenter's ideas from McLuhan's. It truly was a school of thought at University of Toronto. This book should get as much attention as any McLuhan text. (Note: it is hard to top the double dose of the "Medium is the Massage" in book and audio.)
Margaret Mead is quoted on the back cover saying "Astute staccato comment on present and needed changes in sensory modes, against a background of fantasied primitive life, annotated with extraordinary photographs." Ditto about the photos.
The "Visual Pun" is worth every cent you'll pay for this book that cost $3.95 in 1970. If you've got any McLuhan books, consider adding this to your collection - while you can.