WHEN A LITERARY CRITIC sets out to write a novel of fantasy, he'd better be sure of his inspiration. The profession has had its share of success in the genre; C.S. Lewis and J.R.R. Tolkien are only the most celebrated of a long line of academics to turn their esoteric knowledge into imaginative epics. But there is always a danger lurking in the author's fascination with his own private world of symbols: if he gets lost in it, he can easily forget his duty to tell a tale.

Harold Bloom's earlier studies of William Blake and W.B. Yeats, both impressive works of literary criticism, should have taught him to beware these dangers. But in The Flight to Lucifer. Bloom's latest work, the author's zeal to communicate an obscure but not inherently tedious theory of religion overwhelms him, and he does not live up to his chosen role of myth-maker. Bloom clothes his doctrinal argument in a flimsy mantle of epic fantasy. He would probably have done better to write an essay than this dreary mess.

Bloom's troubles begin with his characters. The protagonist is a human being named Perscors, whom we follow from earth to the planet Lucifer. Unfortunately, the hero has no personality to begin with, and picks up none along the way--Bloom just seems to forget to give him one. He rampages across Lucifer, a sword in each hand, splattering limbs and skulls across the countryside, but earns less sympathy from the reader than even such legendary softies as Conan the Barbarian.

His companion, Valentinus, travels to Lucifer to regain the memory of his past life, that of a second-century seer of the Gnostic sect. Valentinus is equally faceless, and takes no interest in the fate of his friend. The two travel from world to world courtesy of Olam--an Aeon, one of the super-natural beings of the Gnostic mythos. Curiously, Olam is the most well-characterized of the three, revealing touches of peevishness that are the only human moments in the book.

Bloom could hide behind the label of allegory easily enough, and claim that his novel is only meant to illustrate a Gnostic view of the universe. But the book is ill-argued and difficult to finish reading, and will not make too many converts.

Whatever fascination The Flight to Lucifer holds lies in the historical and philosophical interest in Gnosticism itself, not in Bloom's bankrupt dramatization of it. The Gnostics envision a complete reversal of Biblical myths on the order of Blake's Marriage of Heaven and Hell. In their version, the Old Testament's creator-God becomes the evil Demiurge, who created the physical world to imprison man and estrange him from the true God--who is not part of Creation at all, but an alien being to whom men with true knowledge, or gnosis, seek to return. The doctrines make provocative theology and a fascinating attack on the Gospels, but Bloom can't find enough concrete material there to shape into a good fantasy novel. Instead of focusing on a few key symbols and investing them with emotion, he throws them together and mixes them up, like a Chinese chef tossing ingredients into a wok. Bloom allots most of his characters at least one dream in each chapter, filled with mystic beasts and numbers and events. The symbolic overkill is sure to lose all but the most persistent reader, and confuse the author's theories as well.

Bloom is obviously over-learned. Perhaps if you studied The Flight to Lucifer with the care the author devoted to Blake and others, it might yield allusions, internal consistency, and lots of symbolic geometry. But Bloom doesn't make the effort attractive enough; his book lacks any felicities of description, characterization or narrative. For one thing, its 52 chapters, each four to six pages long, leave no room for any sort of rhythm in the plot. Even worse, the book's brevity makes a mockery of its epic pretensions.

Every great fantasy novel has its great crisis, whether a battle, a speech, or a quest fulfilled. When Perscors realizes the power his humanity has over all the abstractions on Lucifer--not a bad way in itself to work out the novel--he shouts "My epiphany is here!" So much for simple human dignity in Bloom's over-intellectualized wasteland.

By writing this sort of book, Bloom begs to be compared to C.S. Lewis. The comparison does not flatter him in any way. Lewis could get away with gross reliance on unalloyed religious faith because he also possessed an H.G. Wellsian flair for description of other worlds. Lewis never lost sight of the individuality of his characters, nor the need to entertain his readers. Bloom misses both Lewis's faith and his skill.

Bloom's failure must be diagnosed as one of the heart, not the head. His agile mind latches onto a bit of esoterica and clearly delights in its possibilities, but cannot communicate any enthusiasm. It is indeed a shame that Bloom cannot join the visionary company of his betters in myth-making--but too much criticism has apparently blinded his imagination.