In Saul Bellow's novel, a man much like Bellow chronicles the last months of a man much like Allan Bloom.April 23, 2000By JONATHAN WILSONWe live in a thought-world, and the thinking has gone very bad indeed.'' Thus Saul Bellow, 13 years pre-Regis, in his foreword to Allan Bloom's controversial book ''The Closing of the American Mind.'' Now here he comes, at the age of 84, writing in his gold-standard prose as an antidote to mindlessness, in a lively, lovely, haunting novel that caresses Allan Bloom's life via the thinly disguised eponymous figure Abe Ravelstein. It will be remembered that Bloom, a life-term academic with a fine reactionary mind, wrote what was by contemporary standards an esoteric text, but one with a message about the state of higher education that was concise and economical enough to excite the right: rock 'n' roll had dulled a generation's brains, the wisdom of the Greeks was lost in a welter of insignificant relativism, knowledge of American history had been replaced by ''a smattering of facts learned about other nations or cultures.'' This was a fight everyone wanted to get in on. In short order Bloom became that peculiar, once-in-a-decade American phenomenon: the academic celebrity with a ton of money. Who wants to be a millionaire indeed? Bellow's novel is alive to the irony, relishes it, in fact. Suddenly Abe Ravelstein, who in hard times has been known to pawn his valuables to wealthy former students, is scooping up Pratesi linens, cured angora skins and mink coverlets for his bed, and splashing $80,000 on a BMW for his partner, Nikki. In Paris, while on sabbatical, he moves into ''one of the best apartments in the place'' and buys a $4,500 Lanvin sport coat; in London he orders custom-made shirts from Turnbull & Asser. Meanwhile, he continues to dazzle his friends with a nonstop barrage of wit, advice, low jokes and high thought. And he is terribly brave as he does so, for Ravelstein, without a murmur of self-pity, is dying of AIDS. His longtime best friend, Chick, the narrator of the novel, and as skintight to Bellow as Ravelstein is to Bloom (at least in terms of what is generally known of both their lives -- though it should be noted that Bloom, who died in 1992, never publicly discussed his sexuality), is present to witness the peaks and valleys of Ravelstein's last months and to offer his salient memories and reflections on the life. In so doing, Chick both performs a labor of love and more or less fulfills an obligation, for Ravelstein has fingered Chick to be his biographer.I say ''more or less'' because Chick makes a swerve away from straight biography and into a quirky, mediated, reminiscence in which Ravelstein is not always the major player. Bellow, one imagines, perhaps identically charged by Bloom with a responsibility to report the professor's life, similarly skirts biography and memoir and chooses fiction as his medium. ''Ravelstein,'' the novel, thus becomes a litmus test of The Novel's vitality, a demonstration of the elasticity of the form and of its superior ability to get at the heart and soul of a character. In an age of daunting, monumental psychobiography, this is where a lifelong intellectual bandit-trickster like Bellow can stake his claim: truth comes not through piling up fact and piling on one's subject in a hefty 700 pages but via the selective imagination and burnished sentences of an accomplished novelist. Bellow has trodden this path before, most notably in ''Humboldt's Gift,'' where he brilliantly transformed the dazzling depressive poet Delmore Schwartz into the dazzling depressive character Von Humboldt Fleisher.