The novelist Julian Barnes’s new book, Nothing to Be Frightened Of, is a memoir about dying, death, and the fear of death. Since nobody remembers his own death, it would appear to be the one event safely beyond the scope of a memoir. But this book does not fit neatly into that or any other genre. In style and structure, it has something in common with Nabokov’s Speak, Memory; in other ways it is more like Pascal’s Pensées or St. Augustine’s Confessions—except that it’s often funny. Equal parts memory and speculation, Barnes’s book is really the record of his own preoccupation with death, which began early in his life and has not diminished with age (he is sixty-two). He calls the moment when we first become aware of our mortality le réveil mortel. He can’t decide how to translate the phrase, but he has no trouble describing the feeling—

like being in an unfamiliar hotel room, where the alarm clock has been left on the previous occupant’s setting, and at some ungodly hour you are suddenly pitched from sleep into darkness, panic, and a vicious awareness that this is a rented world.

Nowadays an obsession with death is usually described as an illness, to be treated with drugs or talk therapy or both, so that the sufferer can get on with life and not worry too much about questions that may be unanswerable. Barnes is holding out for answers. He isn’t entirely satisfied with the ones he’s discovered so far, but they are not all equally false, he decides, and some are less discouraging than others.

The book begins conventionally enough with stories of the author’s childhood and youth in mid-twentieth-century England, though right away the reader will notice that these stories all seem to mark a few themes: death (of course), senescence, the tricks and traps of memory, and religion. We meet Barnes’s maternal grandparents, Bert and Nellie Louisa Scoltock: he a retired school teacher and veteran of the First World War, she a former Methodist who in early adulthood lost her faith and became a quiet but zealous Communist. He gardened, did carpentry, and read the Daily Express; she pickled, knitted, and read the Daily Worker. Both kept diaries and would sometimes amuse each other by reading aloud from the entries they had each written on the same day many years before, entries of “considerable banality but frequent disagreement.” Mr. Scoltock: “‘Friday. Worked in garden. Planted potatoes.’” Mrs. Scoltock: “Nonsense. ‘Rained all day. Too wet to work in garden.’” The tricks of memory, chapter one.

Barnes’s parents were both French teachers and Francophiles, but temperamentally they could not have been more different. The good son wants to respect their memory, but the writer cannot help taking sides. He describes his mother as an opinionated, garrulous, and self-involved woman, his father as decent and self-effacing. Together they form a kind of type, familiar to readers of Jane Austen novels and viewers of the British sitcom Keeping Up Appearances. Age and sickness reduce them both to another type—the stroke victim, powerless and humiliated, the dying parent dependent on his or her children. Barnes’s account of their deaths is sensitive but bracingly unsentimental. He describes sorting through their effects with the house-clearer (“This is nice—not valuable, but nice”) and then taking the rejects to a recycling center and unceremoniously dumping them out of plastic sacks. He keeps the sacks, deciding they are “far too useful to throw away.”

Then there is the author’s older brother, the famous philosopher—famous for a philosopher—Jonathan Barnes. The book relates an ongoing conversation between Julian and Jonathan about the Big Questions, most of it conducted by e-mail. When they were growing up, Jonathan was supposed to be the clever brother and Julian the “all-rounder.” Now both in their sixties, Jonathan comes off as the more rigorously, blithely skeptical of the two. The first sentence in the book is “I don’t believe in God, but I miss Him.” When Julian asks his brother what he thinks of such a statement, he replies, “Soppy.” Indeed, Jonathan finds much of his brother’s existential anguish soppy, and tries to clear his way through it with logic. There is an undercurrent of rivalry between the two, and a deeper current of mutual incomprehension.

Barnes misses God mainly because of the meaninglessness left in his absence. He is not absolutely sure that God does not exist, but he finds God hard to imagine as anything other than imaginary. (This book could also have been titled Against Wishful Thinking: Including My Own.) He is agnostic not only about God’s existence, but also about the nature of the God who might exist. He is not at all confident that God would conform to our moral expectations. To those who despise the kind of faith that only comes alive in desperation, Barnes replies: “[God] might view things differently. He might, modestly, not want to be a daily, occluding presence in our lives. He might enjoy being a breakdown specialist, an insurance company, a longstop.” Elsewhere, though, he inveighs with the same vigor against the presumption of Pascal’s wager:

It is, perhaps, not so much an argument as a piece of self-interested position-taking worthy of the French diplomatic corps; though the primary wager, on God’s existence, does depend on a second and simultaneous wager, on God’s nature. What if God is not as imagined? What, for instance, if He disapproves of gamblers, especially those whose purported belief in Him is dependent on some acorn-beneath-the-cup mentality? And who decides who wins? Not us: God might prefer the honest doubter to the sycophantic chancer.

It is possible, then, to imagine more than one kind of God, though whether every kind can be philosophically defended is a question Barnes leaves to his brother. As a man who makes his living imagining things, Barnes is ambivalent about the power of the imagination. He is keenly aware of how much we all depend on it, but he is also distrustful of its easy compensations. The imagination embellishes memory. It gives our lives an artificial coherence and symmetry, turning random, discontinuous events into parts of a single story. In the age of faith, the Last Judgment was supposed to ratify this story. God sorted the heroes from the villains and provided a satisfying postscript that tied up all the loose ends. If God could understand and judge us in this way, it was because our lives had been meaningful, intelligible. Every life made sense—the whole universe made sense. This, as much as the promise of eternal reward, was Christianity’s true comfort.

But that comfort is no longer available to us. Or so Barnes imagines. He knows a few intelligent believers, whom he describes with a mixture of envy and pity, but they are just holdovers. Overall, the culture has lost its great enabling myth and is now left to improvise. Of course, many people in this post-Christian world go on living by Christian rules—the Christian conscience survives the Christian faith as a kind of phantom—but the faith itself is no longer a live option. Barnes knows the terrible things that have been done in the name of Christianity, and he catalogues a few of these with Voltairean relish. But it is not Christianity’s crimes that have discredited it in his view; it is the immodesty of its hope. It is simply too good to be true. One answer to this view is Walker Percy’s: A universe without God is too bad to be true.

This life is much too much trouble, far too strange, to arrive at the end of it and then be asked what you make of it and have to answer, “Scientific humanism.” That won’t do. A poor show. Life is a mystery, love is a delight. Therefore, I take it as axiomatic that one should settle for nothing less than the infinite mystery and the infinite delight; i.e., God. In fact, I demand it. I refuse to settle for anything less. (“Questions They Never Asked Me”)

Barnes might find this charming, but he would also find it childish, a perverse refusal to grow up and accept the world on its own terms. Who is Percy, or anyone, to demand that God exist—or to pretend that mystery, delight, and love require a supernatural source? On his sixtieth birthday, Barnes has lunch with T., a Catholic and one of his few religious friends. T. is about to get married (to R., who isn’t Catholic). Because it is his birthday, Barnes allows himself to ask a question that might offend. Why, apart from his upbringing, does his friend believe in God? T. thinks for a moment and then replies, “I believe because I want to believe.” To which Barnes answers, “If you said to me, ‘I love R. because I want to love R.,’ I wouldn’t be too impressed, and nor would she.”

One sees his point. But I’m not sure Barnes sees T.’s. Christians believe that the desire to believe is itself a grace, the gift that makes faith possible. T. does not say he decided to believe; he says he wants to. Barnes does not seem to consider the possibility that this desire may be discovered rather than invented. Of course, it is possible to desire things we cannot have, or shouldn’t. The fact that T. wants to believe proves neither the worthiness nor the unworthiness of belief. But finally faith is not a wager or a conclusion; it is an act. And an act of faith always begins with longing. As St. Augustine puts it in his memoir about death and rebirth, “You have made us for yourself, O Lord, and our heart is restless until it rests in you.” Barnes knows this restlessness well, but for him it implies nothing: our hearts are restless until they stop. Full stop.