San Diego — On a well-to-do street in Edinburgh, Scotland, on Thursday, June 18, a 60-year-old gentleman named Robin Spark received an anonymous package from San Diego, California, and promptly called the police. In a very short time, nine apartments near Mr. Spark's were evacuated, and the area surrounding his building was sealed off. An army bomb inspector advanced on the package, only to find inside something the press later identified, wrongly, as a "whoopee cushion."

Just why Scottish authorities would call in an army bomb inspector to dismantle a San Diegan gag gift was partly answered in the following days' headlines:

"SPARK FAMILY'S FEUD LEADS TO BOMB SCARE," said the Scotsman. "DAME MURIEL'S FEUD SPARKS BOMB SCARE," said the Scottish Daily Record.

"HOW A BITTER FAMILY CONFLICT OVER DAME MURIEL'S FAITH LED TO A LETTER BOMB ALERT," said London's Daily Mail.

The Dame Muriel in question is none other than 80-year-old Dame Muriel Spark, Scotland's greatest living writer, author of 20 novels, including The Prime of Miss Jean Brodie, four volumes of short fiction, three books of criticism and biography, one play, one book of poetry, and, published in 1992, an autobiography, Curriculum Vitae.

Robin Spark is Dame Muriel's son. As the headlines suggest, relations between the two are somewhat strained.

To Americans, British family life often appears comparatively staid, not much given to great shows of affection, to screaming matches, or to letter bombs, real or imagined. The person with keenest insight into why Dame Muriel's relationship with her son has become so publicly passionate is Dame Muriel's brother, 85-year-old Philip Camberg, who lives in a quiet trailer park in Santee. It's Camberg who sent the package Robin Spark imagined, or claimed to imagine, to be a bomb.

"He's a meshuggeneh," Camberg says of his nephew. "Excitable. Sensitive. Been that way all his life. He gets that from his father's side. But never did I imagine Robin would think my package was a bomb. I sent him something called a 'crying towel' that I bought at a novelty shop in El Cajon. I sent it as a kind of joke because he's been giving such a hard time to his mother, who's really a wonderful woman.

"But a letter bomb? The police? An army bomb inspector?" Camberg throws his head back and laughs. "That's the funniest thing I've heard in my life. And I needed a good laugh. I haven't had any since my wife recently died. I think Robin called the police because he wanted to attract attention to himself. Publicity, you know."

Camberg, a retired chemical engineer, immigrated to the United States in 1949 and moved to San Diego in 1963. Despite his many decades in the United States, Camberg still speaks with a light Edinburgh accent, an accent not often associated with Yiddishisms like meshuggeneh.

It is this unusual combination of Scottishness and Jewishness that's at the heart of the conflict between Dame Muriel and her son. Dame Muriel, who converted to Roman Catholicism in 1954, has frequently stated that she was "half-Jewish," that her father was Jewish and her mother Anglican. While she explored her mixed parentage in her fictional and autobiographical work, it was the latter which of late has proved most crucial. As a famous writer, her life, and what she wrote about her life, were given close scrutiny, and not all of it dispassionate. A disgruntled former boyfriend wrote in a book about London literary life that Dame Muriel was, of all things, part Gypsy. Her autobiography, Curriculum Vitae, was her effort to assert, once and for all, her truth.

"So many strange and erroneous accounts of parts of my life have been written since I became well known, that I felt it time to put the record straight," she stated in the introduction. "I determined to write nothing that cannot be supported by documentary evidence or by eyewitnesses; I have not relied on my memory alone, vivid though it is."

Of the other memories she relied upon, one was that of her brother in San Diego who, she stated in the same introduction, was "able to recall names, places, dates, facts, more clearly than I could."

As far as the world was concerned, the "names, places, dates, facts" laid down in Curriculum Vitae were accurate, and the perception would likely have remained so if earlier this year a London professor specializing in Anglo-Jewish literature had not lectured at the Edinburgh synagogue that Dame Muriel's son Robin, an Orthodox Jew, attends. During the course of his talk, the professor mentioned that Dame Muriel Spark was "half-Jewish." There was a stir, then anger. Didn't the professor know, the synagogue's congregants asked, that Dame Muriel was fully Jewish? That her own son, Robin, was a member in good standing of their shul?

To Gentiles, half-Jewish or fully Jewish may seem noncrucial nuances, but to Orthodox and, in America, Conservative Jews, the difference is vital. According to Talmudic law, only someone born of a Jewish mother is Jewish. Anyone else who wants to be a Jew must persevere through a rigorous conversion process that can take several years. The "Who Is a Jew?" question has caused endless havoc in Israel, bringing Knesset members to fisticuffs. In the case of Dame Muriel and her son, the already volatile issue has threatened a man's religious status and a famous writer's credibility.

Robin's response to the professor's offhand remark was immediate. He announced in a Scottish Jewish newspaper that not only did he have documentary evidence that his grandmother, Dame Muriel's mother, was fully Jewish, but that Dame Muriel had "covered up" this fact in her writing. Dame Muriel wasn't amused. So began the "family feud" that grew rapidly into an all-out war waged through interviews, counter-interviews, and letters-to-the-editor published in the London Times and Scottish newspapers. In other words, it was the sort of nasty, high-profile literary dust-up the British press loves.

Even before the troubling headlines, however, it seems Dame Muriel and her son were never very close. Upon returning to England after her unhappy marriage in Rhodesia, she placed Robin in her parents' care in Edinburgh, an arrangement that, according to Curriculum Vitae, was good for everyone concerned. Her parents were glad to have a grandchild in their home. Muriel, living in London, had no money and was struggling hard in England's post-war economy to build a career for herself as a writer. Mother and son led very different lives. Dame Muriel's ultimate conversion to Roman Catholicism, a leap of faith not unheard of among English writers, underscored the distance between her and her son.

Robin Spark claims he enjoyed a "traditional Jewish upbringing" from his grandparents, but Dame Muriel recently told the London Observer he was brought up as an "ordinary Scottish lad." Unless bar mitzvah ceremonies are commonplaces of ordinary Scottish boyhood, however, Dame Muriel's point seems odd. In chapter seven of Curriculum Vitae, she wrote, "My son, who to my parents' satisfaction had decided to be a Jew, also got 50 pounds to pay for a party for his bar mitzvah."

Philip Camberg is perhaps the only person in the world who can make some sense of all this confusion. Camberg, who considers himself "half-Jewish," married, in his words, a "100-percent Jew" and raised two Jewish children. He describes his own childhood home as one of considerable religious confusion. Yes, he says, he was a bar mitzvah, but it was something his father very much wanted him to do.

"But," he continues, "my mother wasn't Jewish. We celebrated Good Friday and Easter Sunday with hot-cross buns like in any Christian home. At Christmastime we hung up stockings like everyone else. My mother may have gone to synagogue a few times, but my sister and I felt she did so only to show off her hats."

Camberg's loyalty to Dame Muriel has enraged his nephew. In interviews, Robin tends to portray himself as bewildered by his "formidable" mother's wrath. But in a May 19 letter he sent to his uncle, after Camberg had publicly vouched for Dame Muriel's credibility, Robin showed that he knew a thing or two about anger, too. The letter, typed in all capital letters, is brief, confused, and vicious. Robin denounces his uncle, accuses him of being an "egotist," and, with surprising impertinence, calls him an "old fart."

"Such disrespect to your 85-year-old uncle," Camberg sighs, looking at the letter. "He's a rascal."

It was the letter that inspired Camberg to send his nephew the "crying towel."

Despite Dame Muriel's and Camberg's statements, Robin maintains that his mother is "fully Jewish." As proof he offers a ketubah, or Jewish marriage contract, signed by both his grandmother and grandfather. According to Jewish law, the two could have had a kosher marriage only if both of them had proven their Jewishness to the Chief Rabbinate's satisfaction. One possible explanation for the ketubah has been suggested by an Edinburgh rabbi who claims that his father, also a rabbi, oversaw the conversion of Dame Muriel's mother.

Camberg says that neither he nor his sister ever heard anything about a marriage contract or a conversion.

"Our mother was a simple country lass. She was a very good woman, a very kind woman. But she was a simple country lass. If she ever signed anything like a Jewish marriage contract, I'm certain she had no idea what it was or what it implied. She certainly didn't consider herself Jewish.

"The real issue here, though, isn't the marriage contract. It's that Robin has tried to defame his mother, which is a terrible, terrible thing to do. She worked very hard all her life, never relied upon anyone. Never asked for help. And she made something of herself. She's received many honorary degrees. She's been invited several times to Buckingham Palace. She's a brilliant woman and I'm very proud of her.

"I think Robin is jealous of his mother's fame, and that's one part of why he's done this. The other is that he feels that she abandoned him. Which she didn't do, by the way. But he's a 60-year-old man. He shouldn't turn on his mother."

Camberg wishes only that Robin would leave Dame Muriel in peace. The Edinburgh synagogue Robin attends is convinced of the marriage contract's legitimacy and therefore of Robin's Jewishness. Dame Muriel has said she's tired of the whole affair -- "I'm 80 years old and want to enjoy my life."

Since the June 18 "bomb scare," Robin has declined to be interviewed by the press.

But a letter Phil Camberg received from his prolific nephew on June 26 would indicate that Robin was unlikely to call a cease-fire anytime soon.

"Old fart," the letter, striking a familiar note, begins. "You are not only Sick in body, but sick in mind (if you can call that sick mind of yours a mind!) You kiss my mother's fat ass and condone her so-called love of Catholicism.... Yes, old fart, if you went to [synagogue] and acted like a decent Jew instead of siding with her, this old slut (yes, she has had many lovers...it's a miracle she didn't get AIDS) who I am ashamed to call my mother, then you would have been a better husband and father to your wife and children, but no, you waste your time with all of a sudden being a support to Muriel Spark, who truly stinks as a writer and lives a false life, as she is nothing but an egotistical and self-centered old woman, much like you with similar unfortunate traits.

"Wisen up, old man, your time is limited....

"Your being a sick and sad old man only emphasizes your Weird and foolish nature...."

"As a religious man," Camberg offers in closing, "and especially as a religious Jew, Robin should remember that one of the Ten Commandments is 'Honor your mother and father.' "