Reading McLuhan has yet to begin on account of a series of mis-takes which disable it from the start. These mis-takes include:

• It is supposed that McLuhan considers the history of media (first speech, then writing, then printing, then photography, then radio, then television, etc) when he in fact considers the history of our knowledge of media. This is the same difference as between a history of the chemical elements (in the first milliseconds of the big bang, say) and a history of our knowledge of the elements eventuating in chemistry. Neither McLuhan’s new sciences nor chemistry can start until their elements are finally isolated as synchronic structural forms: “visual and acoustic space are always present in any human situation” (GV 55, emphasis added).
• It is supposed that McLuhan considers natural or literal ‘things’ instead of formal structures. So (for example) ‘space’ in McLuhan is taken to refer to physical space or, at least, to the different experience of physical space in different ages or places. Or ‘the brain’ and its two ‘hemispheres’ are taken to refer to what he called our pulsating mass of grey matter. These ideas ignore McLuhan’s stricture that “failure in perception occurs precisely in giving attention to the program “content” of our media while ignoring the form” (UM, 209). McLuhan was interested only in such forms and used a term like ‘space’ exclusively to characterize them — and not to refer to some supposedly natural or literal objective thing.  As he wrote to Joe Keogh: “I am not a ‘culture critic’ because I am not in any way interested in classifying cultural forms. I am a metaphysician, interested in the life of the forms and their surprising modalities.” (July 6, 1970, Letters 413)
• It is supposed that singular words or things can ‘make sense’ aside from the formal ratio from which they have whatever significance they have: “Erasmus and More said that a unified ratio among the senses was a mark of rationality” (GV 94). Therefore the need in examining different rationalities to realize that “visual and acoustic space are always present in any human situation” (GV 55) and that “no matter how extreme the dominance of either hemisphere in a particular culture, there is always some degree of interplay between the hemispheres” (GV 62). What is at stake is not “visual space” or “acoustic space” or even “space” at all (and not “left brain” or “right brain” or even “brain” at all), but the structural forms or ratios which are in play in any and all human experience.
• It is supposed that a gradual approach may be made to ‘media ecology’ aside from the articulation of its essential focal structure, its elements and the field it would investigate in terms of these. As if chemistry (say) might be initiated aside from insight into its elements and their field of expression. Instead, media analysis necessarily begins suddenly and necessarily begins with work which is already focused in these ways — however much the required structure, its elementary expressions and their field will forever be subject to further research and revision.

In all these ways, the keys to the study of human experience are formality and synchronicity. But how can our finite intelligence, which never knows more than some part of a formal whole possibly come (diachronically) to initiate such intelligibility? McLuhan’s answer to this question, as broached previously, is that intelligibility is not some invention of humans, but is given to humans for retrieval/replay/recognition/retracing/retracking.¹