Richard Jenkyns believes that, although a "canon" of literary works is necessary in providing us with a stock of appropriate "shared references," such a canon does not have to be exlusively "high cultural."
It is surely vain to suppose that poorly educated and disaffected young Asians can be brought to a stronger sense of belonging in Britain by a diet of Hamlet, Middlemarch and the Psalms. The truth is that shared references and resonances mostly need to evolve naturally, that most of them derive from popular culture, and that many of them are like family jokes. Television has had enormous power as a unifier; this power is now declining with the proliferation of channels and new media, but in their time Morecambe and Wise did more than Milton and Wordsworth to make us feel one people.
The obvious flaw in this argument comes from that "in their time." The accomplishments of Morecambe and Wise notwithstanding, the ultimate point of a canon is that it includes "shared references" that are timeless, not merely of unifying value in a particular historical era. Unless future generations will likely value Morecambe and Wise as much as those "in their time" did (although, who knows, maybe they will), there seems little point in enshrining them in a "canon," which will only come to seem as much an imposition on the tastes of those later generations as Milton and Wordsworth.
(I'd love to see Monty Python's Flying Circus become canonical, but something tells me that 50 years from now not everyone will find the show quite as bracingly funny as I did when first exposed to it in the mid-1970s. To in effect insist that it is that funny by enshrining it in a canon would not accomplish much.)
Jenkyns correctly locates the origin of our notions of a canon in the deliberations of the Church over which Biblical texts deserved its official sanction, but he doesn't really much discuss the two primary purposes for which the concept of the canon has been adapted to secular culture: to help enhance "national greatness" and to create academic curricula. (Sometimes the two projects overlap.) A canon of great writers focuses attention on the cultural accomplishments a country can claim, the contributions it has made to "culture" and "literature" on a broader, global scale. (Thus, say, Great Britain can claim that "its" poetry is perhaps the greatest any nation has produced.) It also allows the academic study of literature to claim for itself a "subject" of study. "Literature" as a disembodied category of "great writing" is unsustainable as the foundation of a curriculum of study; a semi-official list of sufficiently great writers and texts to justify their inclusion in a prescribed set of courses is needed to give literary studies the status of a "discipline," the core elements of which students will be expected to master.
Because I've never been able to accept the asssumptions behind either of these impulses to canon-building, I've never invested much energy in defending the canon against its supposed enemies, those identified by Harold Bloom as the "School of Resentment." Although I agree with Bloom that much of the hostility directed at canonical writers is misplaced and counterproductive, I can't see that preserving the canon in its pre-Theory/Cultural Studies form is either possible or desirable. I have enough regard for most of the texts usually invoked as canonical that I think they will continue to attract readers without the need to place them in a pre-established heirarchy that only invites efforts to divest them of their privileged status, from whatever angle of skepticism or resentment.
Most of the efforts to "interrogate" the canon over the past two decades have not really questioned the need for heirarchy in organizing literary study. Indeed, the focus of much canon-busting has been on making room for other texts, sometimes on replacing existing canonical works with those deemed worthy for other than traditionally defined "literary" qualities. (In some cases, non-canonical works, such as Their Eyes Were Watching God, were shown to have such qualities despite their previous neglect.) The canon was altered or reconceived, not abandoned. Canonization, it would seem, continues to be "socially useful," as Jenkyns explicitly puts it, while the idea of literature as something that mostly provides "shared references and resonances"--or at least should be made to do so--is further reinforced.
If all "great books" can do is allow us to resonate with one another, then I don't think finally abandoning the canon altogether would do much harm. It might do literature a great deal of good, if we can then more profitably think of reading it as a particular kind of experience the ultimate reward of which lies in the experience itself and can't be reduced to its political utility or its role in the academic curriculum. Jenkyns himself, in discussing the popularity of Jane Austen, convincingly maintains that literary works survive through a kind of bottom-up process whereby authors and books appeal over time through their "actual merits." This kind of informal canonization should be enough to keep the greatest books in circulation, while whatever "shared references" they also encourage are references that persist because they're really worth sharing.