John Bayley is the most famous literary critic in the world. He achieved that oxymoronic status, however, not through his classic books on Tolstoy and Shakespeare, his regular contributions to the New York Review of Books and other periodicals, or his career as a professor at Oxford. Rather, he became an unlikely celebrity thanks to his memoirs of his late wife, the novelist Iris Murdoch, and her decline into Alzheimer’s disease. This moving story was the material for several bestsellers and a film, in which Jim Broadbent won an Oscar for his portrayal of the critic.

In “The Power of Delight,” (W.W. Norton, 512 pages, $29.95), Bayley returns from memoir to the subject that has been the his life’s work: literature, above all the fiction and poetry of England, America, and Russia. A thick compendium of essays and reviews, thoughtfully chosen by New Yorker editor Leo Carey from four decades of Bayley’s work, “The Power of Delight” reminds us of Bayley’s unique gifts as a critic. Those gifts are aptly suggested by the title, taken from an essay on the Polish-Jewish writer Bruno Schulz. Schulz praised the art of fiction for offering a “dream of renewal of life through the power of delight”; and if, as Bayley writes, “That is an accurate description of the way his books work on us,” so too it fits Bayley’s own achievement as a critic.

Both parts of the formula — the life that fiction contains, as well as the delight it bestows — are crucial to Bayley’s aesthetics. The kind of pleasure Bayley seeks in fiction, and communicates so infectiously to the reader, is in one sense old-fashioned, as he proudly admits. In a piece on Edward Said, combatively titled “Professional Strategies,” Bayley attacks the academic profession to which he reluctantly belongs, offering a stinging summary of its mindset: “Because the don is a don, he ought to behave like one and not pretend that he is enjoying and thinking about literature for its own sake.”

That, however, is just what Bayley does in these essays: enjoys literature, thinks about it, and enjoys thinking about it.There is no theoretical armor of the kind that Bayley rebukes in his deliciously curt review of Barthes’s “S/Z”: “linguistic and critical discrimination calls for the use of Occam’s razor, not for the deployment of a new para-language.” Neither is there a Leavisian sternness, determined to separate wheat from chaff. Bayley has preferences, of course — he returns again and again to Pushkin and Larkin, using them as touchstones for very different kinds of writing — but not dogmas.

Instead, Bayley approaches each of his remarkably wide-ranging subjects in a spirit of erudite curiosity. Especially in the essays from New York Review, where he is often reviewing a new biography of a canonical author, Bayley interweaves facts about the life with insights into the work.This is not to say that he enforces a strictly biographical interpretation of any of his dozens of subjects; rather, one has the sense that both the life and the work appeal independently to Bayley’s interest. As he writes in the essay “Gossip in Fiction,” “the mainspring of fiction may be the equivocations and uncertainties of the gossip world.” Some of the most striking moments in Bayley’s essays are equally drawn from that world: Laurence Sterne scandalizing Doctor Johnson with a dirty picture; a banker friend sending Thomas Hardy a newspaper clipping about a man named Thomas Hardy, who was on trial for assaulting a relative with a bust of Gladstone.

This is where Bayley’s belief in fiction’s “power of delight” connects with his demand for fiction’s “renewal of life.” If there is a constant theme in these essays, it is Bayley’s pleasure in facts and realities, and his distaste for morals and interpretations. In the earliest piece in the volume, a 1962 essay on “The Point of Novels,” Bayley urges us to mistrust any writer who declares “Life is not like that, it is like this,” warning: “the novelist who begins with ‘life’ begins with a theory.” Abstractions about what life is and how to lead it are the surest way to earn Bayley’s displeasure. Rather than Life, Bayley writes, “most novel readers are interested in … happenings, moneymaking, love-making, committee-sitting, being young, growing old. What actually happened to Arnold Bennett’s old wives,” he insists, “will probably survive Virginia Woolf’s ‘luminous envelope’ or Robbe-Grillet’s obsessed lens.”

This seems a very English kind of empiricism, and accounts for Bayley’s affection for novelists like Anthony Powell and Barbara Pym. By the same token, it suggests the limits of his tastes and sympathies. Even in writers he likes, such as Lawrence and Conrad, he balks at the first sign of authorial assertiveness; when it comes to George Eliot and Wordsworth, he has no patience at all for what he considers bossy moralizing. “We look in vain in [Wordsworth’s] work,” Bayley writes, “for the true ease, the rambling and inconsequential but always growing and vivifying speech of Coleridge.”

But there is a pathos in deliberate artistic self-transformation, which can be one of the chief appeals of literature, especially poetry. Bayley’s resistance to that appeal leaves his portraits of poets like Keats, Whitman, and Robert Lowell looking distinctly idiosyncratic, even as it nourishes his appreciation of J.C. Powys, Turgenev, and other novelists. This is less a defect, however, than one of the preferences that define Bayley’s critical personality — a personality that the reader of these essays will find powerful and delightful indeed.