IT IS PERHAPS as difficult to write a good life, Lytton Strachey said, as to live one. Among contemporary biographers nobody is better qualified to describe the difficulties involved in getting a complex life down on paper than Leon Edel. Author of a masterful five-volume biography affectionately known as "the Henry James quintet," Edel, now 77, is still working at the top of his powers. In Writing Lives, a revised and much expanded version of his earlier Literary Biography, he has brought together in one volume all the writings on biography that he wants to preserve.

Stressing that a biographer must also be a critic, entering into the heart of each piece of prose or poetry as if it were the only work ever written, he suggests that every author's vision is defined by an "individual world of words." The words that appear over and over in these connected essays, Edel's own defining vocabulary, are "structure," "form," "design," and "style." A biography of an artist, he insists, should itself be a work of art, its multiple strands arranged into an illuminating and esthetically satisfying design. It is not, after all, research by itself that makes for a readable life but the imaginative manner in which the biographer selects and shapes the material.

James once likened a novel's idea and form to a needle and thread: "I never heard of a guild of tailors who recommended the use of thread without a needle, or the needle without the thread." The biographer's needle and thread are "selection and design," Edel suggests; scholars who simply present their findings in rigid chronological order "end up not with a garment on their hands but with the bolts of cloth and boxes of buttons. . . . We have, in other words, biographies which are content without form, whereas in the work of art, content and form are one and inseparable."

The last 30 or so years have seen the publication of a great many pedestrian biographies that have no discernible form, that are, to put it bluntly, little more than fact dumps. Written in undistinguished prose and wanting in original insights, these books offer the raw material for a life rather than the life itself. It is necessary for readers to find the implicit patterns and to draw conclusions from a huge mass of untransmuted data -- to become, in effect, the true biographers. Such compendiums or mini-archives, shoveled together rather than composed, clearly offend Edel, and throughout his book he attacks both the general mode and specific practioners.

A biographer, he believes, has an obligation to interpret material (much as a psychoanalyst must analyze seemingly unconnected thoughts), discovering the intricate figure in the carpet. In addition, and this is crucial, he or she must reveal the figure beneath the carpet, that is, the patterns that lie on the underside of a given tapestry. "The public facade," he writes, "is the mask behind which a private mythology is hidden -- the private self-concept that guides a given life, the private dreams of the self." Edel offers several persuasive illustrations of hidden selves including the vexed case of Hemingway.

"Hemingway's figure in the carpet is his pattern of seeking out violence wherever he can find it, seeking out courage, resignation, heroism and perseverance, and avoiding too much feeling. But the reverse of the tapestry tells us that somewhere within resides a troubled, uncertain, insecure figure, who wants terribly hard to give himeself eternal assurance. . . . Life reduced to the terms of the bullring and the prize fight is a very narrow kind of life indeed. The biography of Hemingway that captures the real portrait, the portrait within, still needs to be written."

It is invigorating to hear a Jamesian's thoughts on Papa Hemingway, since they suggest that two seemingly antithetical writers apparently inhiabited the same planet after all. Edel also provides fine insights on other novelists, including Balzac and Woolf, as well as on such fellow biographers as Boswell, van Wyck Brooks, and Ernest Jones. His observations are consistently expressed in language that is liquid and graceful.

In a period that sees academic prose becoming increasingly turgid and jargon-filled, it is reassuring to encounter a scholar who is incapable of writing a confusing or awkward sentence. If, as has been said, a style is a writer's (Illegible Words) posterity, then Leon Edel's credentials are (Illegible Words) order indeed. Writing Lives, like all his books (Illegible Words) composed. It is, in short, a work of art.