McLuhan speaks to us from across a fundamental divide. He speaks to us from an inclusive position where everything in the human domain is always both phenomenal and ontological at once. (See ‘RVM or through the looking glass?‘)
This same phenomenal/ontological inclusivity holds in the physical realm where every material is both something that can be handled as it is found or made and something that can be represented, precisely, by a chemical formula.
This phenomenal/ontological inclusivity in the physical realm resulted from the isolation of the structure of the chemical element in the nineteenth century. The chemical formulas which became possible in this way map the ontological status of materials which always also have a corresponding phenomenal reality: they are known to appear in just this or just that way. Or, conversely, any and every material is known without exception to have an exact chemical formula.
Any misfit between the two phenomenal/ontological sides of this fundamental relation is indicative of a need for research which may reveal new information about either or both. Any misfit is, therefore, revelatory.
The relation is held constant, while its sides are investigated on the basis that it always holds.
Now McLuhan would have us approach any and all artifacts in the human domain in the same way and on a parallel basis.
The “meaning of meaning” is relationship. (TT3)