S.I. Hayakawa’s short (3 page) essay, ‘The Revision of Vision’, appeared as one of two introductions to Gyorgy Kepes’ 1944 The Language of Vision.  At the time, Kepes and Hayakawa were colleagues at the Illinois Institute of Technology in Chicago. There is little doubt that McLuhan knew of Hayakawa’s essay since:

• the other, even shorter, introduction — titled ‘Art Means Reality’¹ — was written by Sigfried Giedion who became McLuhan’s mentor and friend after they met in St Louis in 1943.² McLuhan read everything he could find by Giedion and may well have come to Kepes’ book via him.
• in any case, Kepes’ own text in the book is cited extensively in McLuhan’s 1953 essay ‘Culture Without Literacy’ from Explorations 1 and then again, repeatedly, in The Gutenberg Galaxy (126-127) 

McLuhan must have studied Kepes’ book at some point, or points, between its publication in 1944 and his citation of it in 1953. When he did so he must have read Hayakawa’s introductory essay and not only on account of its bare presence there.  For McLuhan knew Hayakawa from Winnipeg when they lived on the same street³ and he must have heard of him again repeatedly when he taught in the English Department at the University of Wisconsin in 1936-1937. Hayakawa had obtained his PhD in English there the previous year. As  a fellow Winnipigeon, UM English grad and published Eliot scholar, Hayakawa would have been the first thing that came to mind when people heard of McLuhan’s very similar background.

After a year away from Madison, Hayakawa returned in 1937 to marry and to teach for the university in its satellite locations: it is not impossible that he and McLuhan met there just as McLuhan was leaving UW. Later, it was probably through Hayakawa’s 1941 Language in Action that McLuhan was introduced to the general semantics of Alfred Korzybski, which he cited approvingly in a number of early texts, including his Nashe thesis.⁴

‘The Revision of Vision’ sets out, in startling clarity, a number of points to whose investigation McLuhan would dedicate himself in the 1950s:

The Gutenberg galaxy vs electric allatonceness:

We attempt to visualize the eventfulness of a universe that is an electro-dynamic plenum in the representational clichés evolved at a time when statically-conceived, isolable “objects” were regarded as occupying positions in an empty and absolute “space”. (9)

The drama of cognition⁵:

He [Kepes] gives us the “grammar” and the “syntax” of vision: what interplays of what forces in the human nervous system and in the world outside it produce what visual tensions and resolutions of tensions; what combinations of visual elements result in what new organizations of feeling… (9)

The medium and the message:

Mr. Kepes’s endeavor may perhaps best be characterized by the following analogy. To a Chinese scholar, the pleasure to be derived from an inscription is only partly due to the sentiments it may express. He may take delight in the calligraphy even when the inscription is meaningless to him as text. Suppose now a singularly obtuse Chinese scholar existed who was solely preoccupied with the literary or moral content of inscriptions, and totally blind to their calligraphy. How would one ever get him to see the calligraphic qualities of an inscription if he persisted, every time the inscription was brought up for examination, in discussing its literary content…? (9-10)

The practical need for insight into “the meaning of meaning is relation”⁶:

To cease looking at things atomistically in visual experience and to see relatedness means, among other things, to lose in our social experience, as Mr. Kepes argues, the deluded self-importance of absolute “individualism” in favor of social relatedness and interdependence. When we structuralize the primary impacts of experience differently, we shall structuralize the world differently.⁷ (10)

The quest for a topology of experience:

The reorganization of our visual habits so that we perceive not isolated “things” in “space,” but structure, order, and the relatedness of events in space-time, is perhaps the most profound kind of revolution possible — a revolution that is long overdue not only in art, but in all our experience. (10)

Importantly, the quest for a topology of the human domain ties back to the recognition of multiple galaxies of experience, at least one of which might be able to conceive “an electro-dynamic plenum” of relative spaces:

We attempt to visualize the eventfulness of a universe that is an electro-dynamic plenum in the representational clichés evolved at a time when statically-conceived, isolable “objects” were regarded as occupying positions in an empty and absolute “space”. (9)