At the end of 1935, coming up to the last months of his undergraduate career at Cambridge and in search of a teaching job, McLuhan wrote to E.K. Brown, the new chairman of the English Department back at the University of Manitoba. Describing his own experience there from 1929 to 1934, McLuhan wrote that although he majored in English, he had come to direct his major “energies to philosophy, and did [his] best work for Professor [Rupert Clendon] Lodge.” (Dec 12, 1935, Letters 79)¹

Lodge took a “comparative” approach to philosophy in which the first task in addressing any problem or issue was to consider how it would appear in three fundamentally different types of experience, “three well-defined channels”.²

Lodge described this method in a programmatic essay published in Manitoba Essays³, a volume he edited in 1937 “in commemoration of the sixtieth anniversary of the University of Manitoba by members of the teaching staffs of the university and its affiliated colleges”. Lodge’s essay, concluding the volume, was called ‘The Comparative Method in Philosophy’:

How many philosophical alternatives are there? Theoretically it looks as though the number of -isms [realism, idealism, etc] might be infinite. (…) The history of such speculation, however, (…) indicates that philosophical theorizings (…) flow in one of three well-defined channels. (…) Realism interprets experience as a kind of being, idealism as a kind of knowing. It is easy to see that, as indicated, both realism and idealism are one-sided. Experience has been split up into two aspects, and then the whole has been interpreted exclusively in terms of one of its aspects. It is all nature, or all mind. The extreme forms of these views have always invited criticism. To interpret the whole in terms of one of its parts, whichever part we take as fundamental, can hardly be sound. Obviously the only sound method is to interpret the whole in terms of the whole. Consequently a third type of philosophy has tended to develop: a philosophy which tries to be true to experience, and to avoid all abstract and one-sided theorizings. This attempt at interpretation has taken many forms. One of the best known is called “pragmatism”.
(…)
Here, then, we have three typical directions in which philosophers move when they attempt to master experience: the realist, the idealist, and the pragmatist direction. In the nature of the case, these directions are divergent. To take one pathway, of itself precludes taking either of the others. If any one pathway is right, then the others are certainly wrong.⁴ So much is clear. But is any pathway right, and, if so, which? How are we to tell?
(…)
Where the differences express, in the end, not merely divergent temperaments but divergent lives, ways of living whose whole background and outlook are diverse, there is no cheap and easy method of deciding between such schools. Each declares with equal sincerity and regard for truth that its own view is and must be accepted as the best. Judged in the light of experience as a whole, each works well.
(…)
Is there any way in which this method [of following one’s “own view”] could be improved? I think there is one way and one way only: namely, by completely reversing the usual procedure. (…) In studying any problem as philosophers, I suggest that we should approach it (1) from the realist, (2) from the idealist, and (3) from the pragmatist standpoint, so as to view it from all three angles. Not that these views can, by some dialectical hocus-pocus, be combined into a single picture. They cannot. As theoretical alternatives each definitely excludes the other two.
(…)
We conclude that, for theoretical philosophers, a many-sided comparative study is of greater importance than adherence to a single view; and that (…) any single view may well be regarded with suspicion.
(…)
If philosophy is essentially speculative, an affair of alternative possibilities, I must study those alternative possibilities, and must not, in my enthusiasm for realism (or idealism or pragmatism) close my eyes to alternative possibilities. In so far as any one alternative (eg, realism) refuses to be regarded as one alternative amongst others, and claims to be in exclusive possession of the whole truth, I must be sceptical of its claims. In fact, in so far as it ceases to be sceptical about its own claims, and becomes convinced realism (or convinced idealism or convinced pragmatism), it loses its open-mindedness and is really ceasing to be truly speculative and philosophical. ln a word, it is precisely such one-sided philosophizing which is anti-philosophical, and not comparative philosophy, with its scepticism directed against one-sidedness. As the speculative construction of interpretations which essentially admit of alternatives, philosophy is necessarily sceptical of one-sided claims; and its proper method of study is necessarily comparative.

 McLuhan came to criticize this method severely when he was in Cambridge:

Lodge is a decided Platonist and I learned [to think] that way as long as I was trying to interpret Christianity in terms of comparative religion. Having perceived the sterility of that process, I now realize that Aristotle is the soundest basis for Xian doctrine.  (McLuhan to Elsie, Herbert & Maurice  McLuhan, February 1935, Letters 53)

It is all important to consider what McLuhan was criticizing in Lodge here — and also what he was not.⁵ What McLuhan considered “sterile” in “trying to interpret Christianity in terms of comparative religion” was the stipulation that “for theoretical philosophers, a many-sided comparative study is of greater importance than adherence to a single view” such that “any single view may well be regarded with suspicion” and “and it is quite possible that all (…) are (…) fallacious”. But to regard Christianity suspiciously as merely one cultural option among many, one that could well be “fallacious”, was, of course, exactly not to be Christian and to distance oneself, at a stroke, from a two-thousand year history⁶ and from (in McLuhan’s case) the faith and social forms of one’s own family for generations stretching back beyond memory.

Put in the terms of Harold Innis, such an option was situated at the extreme ‘space’ end of the time-space spectrum.  Only so could it be oblivious to the violence done to its own roots and to the dangers it might be generating for the future. To be oblivious in these ways was for Innis exactly not to think. Hence the association he proffered between particular time-space assumptions and the “conditions of freedom of thought”.⁷

Further the “suspicion” exercised by such “comparative study” was itself “a single view” and so fell before the critique made by Lodge himself of all such singularities: “experience has been split up into two aspects [here “the comparative method” and everything else], and then the whole has been interpreted exclusively in terms of one of its aspects.” But by what right did “the comparative method” assume this prerogative?  Lodge’s silence on this issue and on its associated assumption that abstract(ed) thought was higher and more valuable than the particulars considered by it lay behind McLuhan’s charge that he was “a decided Platonist”. Indeed, Lodge himself insisted that “philosophy is essentially speculative, an affair of alternative possibilities”.

Moreover, the “comparative method” was utterly abstract in a series of other ways as well.  It had no way of accounting for the relation between its analysis and the objects it claimed to understand.  Nor did it consider its context in a particular time and space. Nor did it have an explanation for the fact that it and its practitioners were utterly finite and yet seemed capable of true perception — how was this communication possible?

As a result of considerations like these (but also, of course, from many others, especially from his deepening knowledge of modern English authors from Hopkins to Eliot, Pound and Joyce), McLuhan took on the task of trying to formulate a discipline that would evade the problems of Lodge’s “comparative method” — but that would preserve certain features of that method, especially the recourse to “well-defined” types in the analysis of human history and society. This quest would find its first fruit in McLuhan’s PhD thesis almost a decade later (1943) in which the three arts of the trivium would be used both as a subject in the history of Europe for two thousand years (roughly 400 BC to 1600 AD) and as a background “dispute” in the works of Thomas Nashe. The next year McLuhan gave a lecture in St Louis bringing the terms of his thesis into the present: ‘An Ancient Quarrel in Modern America’ (published in 1946 and later included in The Interior Landscape). And his whole career thereafter would be dedicated to such questions as: How to define the fundamental structures (plural) at work in individual and social history?  Just how do these structures work, in terms of their genesis, their interactions with one another and their “penetration” of mind and society?  And how might a collective study of these matters be initiated?

All of these questions went back to Lodge’s “comparative method”.