At the top of the page, an argument is being pursued. It is a political argument; right now, it is taking up the rightward drift in Western politics since 9/11. "Next week there will be federal elections in Canada," the voice is saying, "and the Conservatives are tipped to win." In the middle of the page, the author of this argument is writing a letter to his secretary. Not his secretary, exactly–the neighbor he has coaxed into typing his notes. She is young, married, half-Filipina and crushingly sexy, the kind of woman who gives men ideas they can't get rid of. He's paying her three times what the work is worth, but they've had an argument, and she has refused to go on. "You have become indispensable to me," the letter begins. At the bottom of the page, the young woman is reporting a conversation she has had with the man she lives with. He has been tapping into her employer's computer, but not because he wants to spy on his private thoughts. He's interested in other things. Like what, she's asked. "Like his finances," he says. Her employer is old, and rich. "Like what is going to happen with his assets after he dies."

We are about halfway through J.M. Coetzee's eleventh novel, Diary of a Bad Year, and we have gotten used by now to the ways it wants to be read. The page is divided in three, horizontally, suggesting an archeological dig, or a kind of play, or the layers of the self. At the top, a writer we know at first as "Señor C" is delivering a steady flow of brilliant ideas, on the nature of political life, on the "war on terror," on the slaughter of animals–his contribution to Strong Opinions, a collection of meditations by six eminent authors. Beneath that, the writer's thoughts on his typist, Anya. At more than 70, he's too old for lust, or so he believes; the throb she evokes he calls, sentimentally, "a metaphysical ache," "diffuse and melancholy," "something to do with age and regret and the tears of things." Beneath that, her thoughts on him, far less courtly. Anya is vain, profane, contemptuous, cruel. What he calls "a derrière so near to perfect as to be angelic" she calls, shaking it in his direction, "my behind, my delicious behind." (Alan, her crude, sweaty lover, calls it, simply, her "bum.")

The structure establishes a rhythm. We read a few lines of analysis, then two bits of narrative. On each page, three voices, three perspectives, three threads of monologue, picked up and let go in turn. The art is visual as well as verbal. Ironies ricochet from layer to layer: the frustrations of political choice at the top of the page become the frustrations of sexual choice in the middle; the "gamble" of nuclear deterrence becomes the "gamble" of Señor C's offer of employment. At first, each layer is self-contained within its page, but as desires become more exigent and narrative momentum builds, Coetzee starts to violate the integrity of the structure, running first paragraphs and then sentences across the page break, forcing us to read out of sequence, make our own unsatisfying choices. A temporal friction also develops. Señor C tells one side of the story; then, pages later, in Anya's narrative, we get the things he left out. Opinions we read many chapters ago only now register in Anya's consciousness, as she types them up, and in her mocking conversations with Alan.

The young couple have no end of fun at the old man's expense. So out of date, so pompous, so transparent in his feeble lust. Alan is a business hustler who fancies himself an intellectual; Anya is sure he'd wipe the floor with her employer in debate. But what else will he do to him? By the time we get to Señor C's letter of supplication and Alan's boast about his spyware, we're worried about what these callous young people might be capable of. We've read Coetzee before, and we know the depths of indignity to which vulnerable old people can be brought, especially aging liberals who think their decency keeps them safe.

There are surprising parallels here with Philip Roth's latest novel. Exit Ghost also gives us a love triangle of sapless old writer, beautiful temptress and snorting young bull. Both books announce an exhaustion with the making of fiction, at least on the part of their protagonists. Both allude, in connection with questions of finality, to Hamlet, Roth's novel in its title, Coetzee's in its last lines. Together, the two books point to larger parallels between their authors' work. Both writers have devoted much attention, especially of late, to the experience of age. The literature of old age is a slender one before the nineteenth century, even before the twentieth. King Lear, Oedipus at Colonus and a few other works stand against the vast literatures of youth and adulthood. But now that writers are living longer and staying stronger, we seem to be entering a golden age of the literature of age, and Roth and Coetzee are perhaps its greatest exponents.

The circumstance points to still deeper affinities. However different the two may be in style, spirit and background, they are both pre-eminently writers of the body–Roth of desire, Coetzee of suffering. The difference helps explain why Coetzee has been writing about old age since before he turned 40 while Roth has come to it only of late. For Roth, old age is the end of what life is all about; for Coetzee, it is the moment when life reveals what it has been about all along. Coetzee revises Descartes's cogito to something like "I suffer, therefore I am." "Whatever else," he has said, "the body is not 'that which is not,' and the proof that it is is the pain it feels." Why not, equally, the pleasure? But Coetzee doesn't think that way, however much, were he equally given to philosophical reflection, Roth might.

The underlying similarity between these two amanuenses of the body may help explain still another convergence. Both are autobiographical novelists in the highest sense, writers who interrogate the condition of writing, the labor of drawing material out of the self. This is obvious in the case of Roth, who has worked through this problem by creating authorial figures who teasingly approximate himself. Coetzee, who has remarked that "all writing is autobiography" but who has also called autobiography "autrebiography," has done it by creating authorial figures who pointedly differ from himself. Roth is interested in the self as subject of fiction: how one's life is turned into narrative. Coetzee is interested in the self as agent of fiction: how one turns life into narrative. Roth seeks to make contact with the self one writes about. Coetzee seeks to make contact with the self that writes. Roth's name for the relationship between the self that says "I" and the fictionalized self is "counterlives." Coetzee's name for the relationship between the self that says "I" and the fictionalizing self–a term he used in his Nobel lecture and, in the singular, as the title of one of his greatest works–is "foes."

But Diary of a Bad Year marks a shift to Rothian procedures. "Señor C" is only what Anya, who mistakenly thinks he's South American, calls her employer. He signs his letter "JC," and Alan tauntingly calls him "Juan." "John C.," then, halfway toward his creator's "John Maxwell Coetzee." The parallels multiply. JC, like JMC, is a divorced South African novelist, critic and retired professor of literature living in Australia. JC, like JMC, has written many volumes, including a novel called Waiting for the Barbarians and, in the 1990s, a book on censorship. Both men gave a speech in 2005 at the National Library of Australia denouncing the new security legislation, and both were taken to task by the Australian, a Murdoch broadsheet. But there are differences. JMC was born in 1940, JC in 1934. JMC has had two children and lives with his partner. JC is childless and alone. JMC is a Nobel laureate and the only writer to win two Bookers. JC has "a modest reputation."

JC, then, both is and is not J.M. Coetzee, even closer to his creator than Nathan Zuckerman is to Philip Roth. In particular, he seems to represent the ascetic, taciturn, publicity-averse Coetzee's self-conception or inner reality: a little older than he actually is, a lot more solitary, not nearly as big a deal. So, are those "strong opinions," which make up the largest share of the novel and give the chapters their titles ("On democracy," "On intelligent design," "On Tony Blair"), Coetzee's own? Again, yes and no. The whole question of what it means to have opinions, of the relationship one has to one's opinions, is something Coetzee has been wrestling with for a long time, most conspicuously in Elizabeth Costello. There's a reason that book, for all its engagement with issues like animal rights and the responsibilities of art, is a novel about a writer who delivers lectures, not the lectures of a writer. "I have beliefs," its protagonist says, "but I do not believe in them." Opinions, for Elizabeth Costello and in Elizabeth Costello, are not positions but hypotheses, poetic ideas, arrived at more through the empathetic processes of storytelling than the logical procedures of reason. "She hates sentences that hinge on because," the narrator says. "The jaws of the trap snap shut, but the mouse, every time, has escaped."

It is a very modern thing, this business of having opinions, a need compounded of Protestant individualism and electoral democracy. It is only modern personalities who struggle to develop opinions that are correct and well informed, who define themselves and measure others by the opinions they hold, who read journals of opinion like this one. (I have a friend whose immigrant grandmother wanted to introduce her to a young man. "He's like you," the old woman said. "He's got a lot of opinions.") This "rise of opinions" can be traced across the literature of the last several hundred years. It makes itself felt in Middlemarch, for example, and in the difference between Mrs. Wilcox and the Schlegel sisters in Howards End. If it has a single point of origin, it is Montaigne, whose essays are Coetzee's clearest models in Diary of a Bad Year.

Coetzee's continuing examination of opinion-holding begins there with the tripartite division of the page, which, in the drama it embodies, enacts a kind of metaphysics of the self. At the top, the voice of analytical reason, authoritative, imperturbable, self-contained and utterly oblivious to what lies beneath it. Then, in the middle, the voice of emotion and need, vulnerable and confused, standing apart–literally, graphically–from these strong opinions. The ironies the juxtaposition creates are all too obvious, as Anya is happy to point out: "My guess is he unbuttons himself when I am gone and wraps himself in my undies and closes his eyes and summons up visions of my divine behind and makes himself come. And then buttons up and gets back to John Howard and George Bush, what villains they are." Opinions, in this view, are just a distraction from what's really going on, the animal making itself feel tall by getting up on its hind legs. Another way to put this is to see JC and Anya as together constituting an allegory of the self. If the text's upper registers represent the head and heart, Anya's voice, its lowermost stratum, represents her favorite body part, the bottom. Or more broadly, as in Rabelais and elsewhere, the body as such, with all its bawdiness, flagrant urges and wicked laughter–the part of himself that JC has lost touch with, the part that feels alien and even hostile to the pretensions of the opinion-making intellect. "His secret aria," Anya calls herself, punning on "segretaria." "His scary fairy."

Yet it is not finally JC's opinions that are being anatomized; it is Coetzee's. That is the ultimate significance of Anya's presence in the margins of these essays, this autobiographical fiction. JC is Coetzee, or a part of him, and so is Anya. If she weren't, he couldn't have brought her forth. "Writing is dialogic," Coetzee has said, "a matter of awakening the countervoices in oneself and embarking on speech with them." And that is exactly what arises, over time, between JC and Anya: a dialogue. At first, they can't even understand each other. He speaks his opinions into a tape recorder and she mishears him, returning transcripts that have "papers and papery" for "Papists and Popery" and "somewhere in the urinals" for "somewhere in the Urals." He thinks she's an ignorant child with her mind in the toilet; she, resenting his condescension, thinks he should write about something fun, like cricket. But gradually they begin to listen to each other. He even allows her to correct an idiomatic error: in Australia, she explains, it is not "talk radio" but "talkback radio." But when we'd come across the term several chapters earlier, it was already in the correct form, which means that that passage, and who knows how many others, already reflect her shaping presence. The phrases in question are emblematic: he talks to her, and she talks back. The "strong opinions" are Coetzee's, but they are conceived, as it were, collaboratively, the brainchild of his disparate voices.

All this helps explain why the essays Coetzee does publish under his own name are so much less interesting than the ones that appear in his novels. His latest collection, Inner Workings, gathers five years of literary criticism, most of it written for The New York Review of Books. Its twenty-one pieces, on a range of figures from, for the most part, the German and English cultural spheres–Robert Musil, Günter Grass, Graham Greene, Saul Bellow, Nadine Gordimer–are highly intelligent and formidably erudite, but they lack not only the imaginative engagement we might expect from the literary essays of a great novelist (and that we find so abundantly, for example, in Virginia Woolf's) but also the probing brilliance of Coetzee's early nonfiction, which was also much more wide-ranging in form, subject and idiom. The pieces in Inner Workings feel, above all, dutiful: a thumbnail biography, some notes on translation, a few pages of analytic summary, often illuminating, occasionally close to pedestrian, always reticent about passing judgment.

Not just dutiful: ostentatiously dutiful. Coetzee seems deliberately to frustrate our desire for rhetorical power and formal beauty, two qualities that literary criticism is capable of possessing in abundance, letting his essays peter out with a minor point or a few cavils about translation or a bibliographic note. If he seems to be writing criticism against his better judgment or at least against his inclination, that may be because he is. In Doubling the Point, which combined the early nonfiction with a series of searchingly self-analytic interviews, he complained about "the rather tight discourse of criticism." "If I were a truly creative critic," he went on, "I would work toward liberating that discourse–making it less monological, for instance. But the candid truth is I don't have enough of an investment in criticism to try."

Many years later, in Elizabeth Costello and now in Diary of a Bad Year, he has begun to try. The monologue has become a dialogue. Elizabeth Costello engages a variety of interlocutors in her travels as a public speaker. JC engages Anya, and not just in the sense that she corrects a phrase or two. Their falling-out leads him to re-evaluate "not my opinions themselves so much as my opinion of my opinions." He learns to see them through her eyes, comes to regret their strongness, their hardness. In a postscript to his letter, he promises "a second, gentler set of opinions," more personal, some of which will take up suggestions she has let drop. And that is what we get in the novel's last third, or at least the top third of its last third, essays on aging and boredom and the writer's own father, more narrative in style and generous in spirit. "Soft Opinions," she calls them.

The adjective could apply to the novel as a whole, its ominous title notwithstanding. Diary of a Bad Year sets up the typical Coetzeean situation: a white person, privileged but vulnerable (through age or disability or isolation), comes to rely on a person of color, a dependent or inferior of some kind, for sustenance and safety. The scenario, like the prose, is mercilessly spare: two wills face to face, scraping together like metal against metal. In the normal course of things, the white protagonist is inexorably stripped of every comfort and dignity, the bare bones of the human situation exposed with an allegorical directness reminiscent of Beckett.

But here, Coetzee gives us a soft landing. Instead of humiliation and suffering, compassion and communion. He seems to be mellowing with age. His last novel, Slow Man, ended in a similarly gentle fashion. It must also be said that after an unbroken string of triumphs that began with his first work of fiction, including a half-dozen masterpieces that establish him, in my view, as the supreme English novelist of the last thirty years and the greatest living writer in the language, these last two works fall short of the spiritual and imaginative intensity–the Dostoyevskian sense of prophecy, to use E.M. Forster's term–that distinguish their predecessors. Like Exit Ghost, the new novel might both enact and announce its author's withdrawal from the seas of fiction-making, or at least from its tempests. When Anya asks JC why he doesn't just write a novel, he tells her that he no longer has the endurance. "To write a novel you have to be like Atlas," he says, holding up a world on your shoulders. The new novel is fragmented in form, and its narrative portions amount to the length of a novella. As Roth does in Exit Ghost, Coetzee introduces the process of aging not merely into the subject of his fiction but into its very form.

Even if the temperature of the new novel is lower than that of its predecessors, its commitments are the same. Coetzee is and always has been, in the deepest sense, a Christian writer. He has written scorchingly of the Calvinism of his Afrikaner upbringing, but what he has called, in another context, the "Calvinist categorical imperative of absolute urgency and absolute stringency" precisely describes his work. "I am not a Christian," he said in Doubling the Point, "or not yet." But what he means by the word is clearly something very different from what passes in the marketplace. The initials "JC" are not deployed casually in Diary of a Bad Year; they signify not Coetzee's belief in his own mission or election but his acceptance of the principle of imitatio Christi–the obligation to receive Christ as one's ethical norm. When Coetzee says he's not a Christian yet, he means he still falls short of that unappeasable ideal.

Nothing shows up the blather of the "God wars," on both sides, like this kind of moral seriousness. In the philosophical realm, if not, alas, in the political one, the question of the literal truth of religious ideas is utterly beside the point. For what it's worth (precisely nothing), Coetzee gives no evidence of possessing that kind of belief. What matters is that he regards Christian ideas as spiritual realities, moral realities: heaven, hell, sin, the soul, suffering, grace, redemption, love; Christ and Judas, angels and demons, the thief in the night and the least among us.

Matters are no different in Diary of a Bad Year, even if the ratio of salvation to suffering is radically improved. JC and Anya help each other toward a modicum of redemption. She learns to think of herself as something more than an ass with a brain attached, and so does he. Eros gives way to agape, spiritual love, and if the path is smoothed with a little sentimentality, Coetzee allows his characters their small self-deceptions. As in so much of his work, the ethical crux is duty of care–in particular, care for the dead, the one form of kindness that we can never repay, and that saves our bodies when they are all we have left. JC has a dream that comes to haunt him, "about dying and being guided to the gateway to oblivion by a young woman." For the greatest of these is love.