When a spot of light hits our retina at its blind spot (where there aren't any photoreceptors), our brain fills that part of our visual field by extrapolation. We usually don't even notice. Literature can do the same thing. Non-fiction is constrained by facts. Facts are easily manipulated and never paint a full picture of a person or an event. There are too many blind spots, too many hidden motives. Fiction, by contrast, can fill in the gaps between the facts. It necessarily presents an impression, an over-arching framework that selects certain facts and disregards others. If it's fictional biography, it might not be true-but it will probably be a truer-to-life.

Why did Saul Bellow choose to fictionalize the life of his dear friend, the late Allan Bloom? Perhaps it is because the facts of Bloom's life require a hermeneutic to frame a relatively coherent picture.

Bellow is the narrator of Ravelstein. He assumes the character of "Chick," long a friend to Ravelstein, an intensely intellectual professor at an elite Midwest university.

Ravelstein taught in comfortable obscurity (though he was in debt), until, at Chick's urging, he put to paper his ideas on the life of the mind. Ravelstein became instantly famous, in the U.S. and overseas. And so, to return the favor, he has asked Chick to write his memoirs. He was traditional, conservative and gay. The book tries not to linger on his homosexuality-Ravelstein certainly didn't consider it the defining aspect of his personality-but since he is dying of AIDS, it is rather unavoidable.

Some of the exposition, and there is lots of exposition because the book focus on moments, is necessary-watching Ravelstein finger through silks in a Paris boutique, for example. But the reader often longs for something more concrete than the image of an effete, successful intellectual on a Paris shopping binge. The sum of Ravelstein's character is revealed in ordinary interactions, rather than when his intellectual or personal muscles are challenged.

Bellow writes many philosophical asides into the book. These very brief but highly content-full paragraphs remind us not only of Ravelstein's appetite for all the belles lettres, but also, by proxie, of Allan Bloom's own writing style. In the Closing of the American Mind, the screed on anti-intellectualism and academic nihilism that made him rich and famous,Bloom dispatches most Continental philosophy in a page, and postmodernism in a few short paragraphs. Here was a man who saw in grand narratives but could very easily produce piquant details at the first challenge.

Bellow picks and chooses at details and fills in the context with tight prose. One example will illustrate. Early in the novel, he devotes hundreds of words to a description of a typical evening at Ravelstein's Chicago apartment, watching basketball with his male grad students. The deeply Athenophilic Ravelstein is surrounded by eager, virile, attractive young men-"Ravelstein's young men." Bellow writes, "At his basketball parties, Ravelstein passed pizza slices among his graduate student guests, his bald head swiveling toward the busy, colored TV screen behind him. His lot, his crew, his disciples, his clones, who dressed as he did, smoked the same Marlboros and found in these entertainments a common ground between the fan clubs of childhood and the Promised Land of the intellect toward which Ravelstein, their Moses and their Socrates, led them."

It is the model of Platonic friendship: the younger, with physical beauty (nature's kiss), and the elder, with a developed life of the mind, conjoining in a discourse for their mutual pleasure. I am told that Bloom had these same, intense, friendships and was fascinated by male companionship in general. Ravelstein's own companion, a forty-years younger Chinese intellectual named Nikki, is fiercely devoted to him. And yet there are hints that Ravelstein couldn't live up to the Greek ideal-him, the mature erastes, doting on his loving, ephebic eromenae and enjoying their beauty.

At one point, Ravelstein cryptically asks the narrator (the Bellow character, called "Chick") for $500 dollars. I say cryptically because a fuller explanation was written in an earlier draft of the book-Ravelstein had to pay a beautiful, 16-year-old African-American male prostitute for sex. For some reason, and much to the consternation of reviewers like Christopher Hitchens, Bellow chose to excise the more salacious item from the draft of his published work.

I also wish I knew where Ravelstein's voracious and caustic conservatism originated. We get very little of Ravelstein's early life or formative academic experiences-the real-life Bloom, at one point, was nearly run out of Cornell at one point.

So what, in the end, is this book? As fiction, it could simply be a musing: a sensuous, aging intellectual persona, thoroughly modern, dying of AIDS in a post-modern age. There is plenty about the mercurial politics of elite universities to sustain a deeper narrative about modernist men professing a fragmenting discipline.

And yet, the book is about Allan Bloom. Nearly every reviewer-me included-reads the real life Allan Bloom where Bellow wrote Ravelstein. We can't disentangle the two, and I'm not sure we're supposed to. I find it interesting that Bellow has apologized publicly for revealing so much about Bloom's life. And the book's hesitancy is testament to this being a long-standing conflict for Bellow.

In the end, if his portrait of Ravelstein is an accurate analogy, Bellow saw Allan Bloom as passionate, sexual, a lover of young (very young) men, guided as the Greeks were by moral aestheticism. And yet he was a firm contrarian, deplored action on impulse, and was convinced, almost mythically, of the steadiness of certain virtues and of the necessity of a reflective life.

It is often easier to express contraries in literature than life, particularly when they involve that murky thing known as character-what lies behind personality, through artifice, beneath facade, and within the heart.