McLuhan's strategy (which he compares to Joyce) is vivisective, a presentation of the living community of men in action. It is, therefore, itself a practice-poetic activity not theorizing in the usual sense we would understand today. This provides it with a strength that no theorizing can achieve, for while he is not producing a theory and never claimed to be, he is thinking and elucidating the way communication works in much the way a psychoanalyst engages in a process of elucidation with and about the one being analyzed. His Letters clearly reflect that practice and should provide a basis for a renewed interest in his work informed by a much deeper understanding.
N.B. see :
McLuhan-and-JoyceBeyond-Media