Muriel Spark (1918-2006) remains best known in the United States for “The Prime of Miss Jean Brodie” (1961), a darkly comic novel depicting the influence of a charismatic but ruthless teacher upon a quartet of young girls. Many Spark fans, however, would choose “Memento Mori” (1959) as her finest book — a philosophical comedy about old age, personal relations and religious belief. In it, a group of elderly friends starts to receive telephone calls in which an anonymous voice whispers: “Remember, you must die.”

In conjunction with the essay collection, “The Informed Air,” New Directions has reissued “Memento Mori” and seven other Spark classics, including such favorites as “The Comforters” (1957), “The Ballad of Peckham Rye” (1960) and “A Far Cry from Kensington” (1988). Anyone in want of civilized entertainment — to use an old-fashioned phrase — need look no further for this summer’s vacation reading. Really, how can you go wrong with a novelist who was a particular favorite of both Evelyn Waugh and Gore Vidal?

At her best, Spark possesses a sly, skewering style, as well as a profound interest in life’s mysteries, and an imagination that segues readily from the realistic to the supernatural. For example, her famous ghost story, “The Portobello Road,” is both macabre and funny, its unsettling mixture of tones building to a shocking, magnificently deadpan sentence that will take any reader’s breath away. But Spark always enjoys surprises: In one of her essays she recalls her childhood fascination with the Bible and her impression of God: “I thought him a charming and witty character with a ready answer, and with a lot of conflicting sides to his nature. I liked God.”

Born to a Jewish father and Gentile mother, Spark grew up in Edinburgh, Scotland, where “the puritanical strain . . . is inescapable, but this is not necessarily a bad thing. In the south of England the puritanical virtues tend to be regarded as quaint eccentricities: industriousness, for instance, or a horror of debt. A polite reticence about sex is often mistaken for repression. On the other hand, spiritual joy does not come in an easy consistent flow to the puritanically-nurtured soul. Myself, I have had to put up a psychological fight for my spiritual joy.” Spark herself eventually married, gave birth to a son, divorced, took lovers, flirted wildly with men and, according to her biographer Martin Stannard, once even felt a bat’s squeak of sexual interest from the critic Lionel Trilling.

The pieces in “The Informed Air” remind us that Spark became a novelist only in her 30s. Before turning to fiction, she wrote poetry, important biographical studies of Mary Shelley, the Bronte sisters and John Masefield, and did a good deal of reviewing. But in 1951 she impulsively entered a short-story contest that offered a prize of 250 pounds. After scribbling “The Seraph and the Zam­besi” in just one afternoon, Spark then borrowed some needed typing paper from a small art dealer’s shop, promising that if she won, she would come back and buy a picture. She did win.

“I bought from my art-dealer friend, for thirteen pounds, a charcoal drawing of a boy listening to a radio, by Stanley Spencer. I bought a dress for six pounds, the first new dress I had had in four years. I gave my mother fifty pounds to pay for my son’s bar mitzvah (we were a mixed-origin family, and my son wanted to be a Jew), and another fifty pounds went to another needy author, who, strangely enough, began to detest me from that day.”

Spark tells us that reading John Henry Newman finally led her into the Catholic Church, “an important step for me, because from that time I began to see life as a whole rather than as a series of disconnected happenings.” She points out that Cardinal Newman’s “reasoning is so pure that it is revolutionary in form. He does not go forward from point to point; he leads the mind inward, probing the secret places of the subject in hand.” Elsewhere, she convincingly argues that Marcel Proust’s “In Search of Lost Time” — her favorite novel — exhibits “something of a tremendous value to the Christian imagination, a sacramental view of life which is nothing more than a balanced regard for matter and spirit.”

The central essays of “The Informed Air” describe Spark’s life in Rome and visits in Italy to Tuscany, Venice and Ravenna, recall her favorite childhood books (“The Oxford Book of Ballads” and Sir Walter Scott’s “Minstrelsy of the Scottish Borders”), and briefly discuss authors as radically different as reverent T.S. Eliot and randy Robert Burns. She also analyzes “Frankenstein” and Mary Shelley’s other proto-science-fiction­ novel, “The Last Man,” before explaining why Heathcliff is her favorite villain and Georges Simenon one of her favorite authors.

Most of these pieces are quite short, but all of them contain telling observations about literary creativity: “I think a stylish life is unsuitable to the writer, and very often in the house where there’s a mild disorder one finds the writer with the best powers of organizing his work. Order where order is due.” She reminds us that the “three Bronte sisters shared a bedroom hardly larger than a linen cupboard; their workroom was the common living room.” About fiction in general, she notes that “happiness or unhappiness in endings is irrelevant. The main thing about a story is that it should end well, and perhaps it is not too much to say that a story’s ending casts its voice, colour, tone and shade over the whole work.”

Whatever her subject, Spark likes to startle. She speaks, with a brilliant choice of adjectives, about Newman’s “touchy inwardness.” She takes note of a 1912 manual on letter-writing: “In an aside, our Gentleman is warned never to write ‘My Dearest Katie,’ lest the loved one be moved to reply ‘Am I to understand that you have other Katies?’ ” And in a clever essay about the Brontes as schoolteachers, Spark even suggests “that if anything could equal the misfortune of their lot as teachers, it was the lot of the respective pupils and employers of Charlotte, Branwell, Emily and Anne.” She concludes that “genius, if thwarted, resolves itself in an infinite capacity for inflicting trouble.”

“The Informed Air” draws to a close with three short reflections on the book of Job. After noting that Job insists he doesn’t blame God for his agonies, Spark boldly writes: “Is this because he is being overheard by God? One wonders what Job might have said had he been assured of complete privacy. With God we have none of us any privacy, in itself an almost intolerable burden. If we did not set God aside in our minds for most of the time, we would be semi-paralyzed. We could never get anything done, never be ourselves.”

This is an astonishing insight, I think. Like Muriel Spark’s fiction, “The Informed Air” offers the reader considerable pleasure, but also frequently delivers something more.

Dirda reviews books for The Washington Post every Thursday.