LUDWIG WITTGENSTEIN The Duty of Genius By Ray Monk Free Press. 654 pp. $29.95

WITTGENSTEIN is fast becoming an emblematic figure of the 20th century. Notoriously cryptic and elusive, he was until recently a philosopher's philosopher. Now, nearly four decades after his death, he has become a voice in literature, anthropology, politics and law.

His life, even more than his work, has preoccupied only an inner circle. Any life has enough contradictions to challenge a biographer, but Wittgenstein's were remarkable. He was prideful but constantly vilified himself and contemplated suicide. He was bristlingly reclusive but infinitely vulnerable to the attention and good will of friends. He was obsessed with the most refined conceptual questions and had only disdain for academics. One of the wealthiest and most cultured men of Hapsburg Vienna, he gave away his fortune, lived austerely, and came to love American detective magazines and movie Westerns.

Ray Monk's ambitious biography is one of several recent attempts to comprehend Wittgenstein's life. It is preceded by Bruce Duffy's compelling fictionalized life, The World As I Found It, and Brian McGuinness's long-gestating study (of which only the first volume has appeared in this country). Given unconstrained access to Wittgenstein's journals and letters and to those of persons who knew him, Monk seems to have been relentless. As author-detective, he has found and interviewed Wittgenstein's surviving friends and acquaintances and has followed up every imaginable lead.

Some biographical subjects -- van Gogh and Beethoven come to mind -- invite a melding of the life and work. What kind of person could conceive and will this art? But philosophical arguments and methods seem to stand apart from the lives of their authors. Monk admirably struggles to make Wittgenstein's philosophy the expression, the flower, of his life. Unlike other commentators, he argues that spiritual anxiety animated Wittgenstein's work. While philosophy is sometimes misunderstood as the search for "the meaning of life," the demon of Monk's Wittgenstein is indeed the meaning of life.

This dimension of Monk's account threatens (or promises) to turn Wittgenstein into a 20th-century cultural paradigm. He is a man cut off from country, religion, family or profession. His neurotic obsessions become a critique of culture. His passionate rejection of a society that worships science and capital echoes Solzhenitsyn and Lawrence. He flirts with suicide, is unable to sustain intimacy, struggles with homosexuality and Jewishness. If Nixon, Einstein, and Malcolm X have been shown to have theatrical dimensions, can an opera or mini-series on Wittgenstein be far behind?

Monk's biography, however, is undramatic. He is aware, perhaps too aware, of the pitfalls of interpretation. He criticizes Bertrand Russell and others for seeing Wittgenstein through their spectacles. So he proffers no spectacles -- and no spectacle. His account is studiedly chronological. He excerpts, digests and comments on the letters, journal entries, published writings and recorded comments of Wittgenstein and those who knew him. What is not revealed in and through such entries is no part of his story. The famous final passage of Wittgenstein's early philosophical monument, Tractatus Logico-Philosophicus, says "what we cannot speak about, we must pass over in silence." Monk's dubious variant seems to be "what Wittgenstein and his friends did not record, I as biographer must pass over in silence."

Such restraint cripples the reader's psychological and physical imagination. For the most part, Monk pictures neither the psyche nor the person of the actors in Wittgenstein's life. Some are more irritable or gentle or clever than others, as their letters and diaries reveal, but these are small and forgettable distinctions. The events as well as the people of Wittgenstein's world appear by allusion. One does not have to be much of a Freudian to regret the absence of serious consideration of Wittgenstein's childhood and youth in Vienna, an adolescence during which two of his four brothers committed suicide. Monk's failure here prevents him not only from giving descriptive answers but from asking the right questions.

Nonetheless, a shapely and sensible story survives these severe filters. Wittgenstein's life changed course often and abruptly. He interrupted his career at Cambridge to serve in both world wars with distinction, to be a rural schoolteacher in Austria, and to seek solitude in Ireland and Norway. Monk's account of the adult life makes these pieces cohere by letting Wittgenstein's troubled letters and journal entries speak for themselves. Listening long and well to Wittgenstein's friends, Monk makes patterns of feeling and action familiar and predictable. He gives us the what rather than the why of the life, a life seen through its symptoms. WITTGENSTEIN as philosopher tries to do something similar. Monk reminds us that one theme of Wittgenstein's thought, from early to late, is the distinction between saying and showing. The philosophical point is that the collective ways in which persons go about acting and speaking show what they believe and how they construct experience even if they cannot say what those foundations are. The distinction has many implications. Monk draws special attention to spiritual ones.

Monk tries to fold Wittgenstein's philosophy into his life -- to make both comprehensible and blend them without seams. He does not quite succeed. The seams show and sometimes split. Monk frequently jerks the reader from philosophical ideas to psychological remarks over the most rickety bridges. He has Wittgenstein talking about mathematical patterns and remarks that Wittgenstein would have wanted to put his own life in "some kind of pattern": " 'I no longer feel any hope for the future of my life.' "

The philosophical passages themselves, roughly half of the book, are hardly self-illuminating. Readers unacquainted with Wittgenstein as philosopher will feel like tourists who have stumbled into the debates of a foreign parliament. Here again Monk tells us what inflames Wittgenstein's philosophical genius and what he says, but not why the important distinctions matter.

We are often most familiar with things we cannot explain. For non-physicists, gravity is a good example. The notion of understanding has two faces: familiarity (with gravity, for example) gives practical but not theoretical understanding. Monk's biography gives us acute familiarity with Wittgenstein and thus gives us practical understanding. The book's effect is cumulative and, in the end, captures well the poignancy of limits set externally by time and internally by Wittgenstein's nature. In unfolding an eccentric and important life, Monk thus stumbles upon limits that are universal and therefore exemplary. Thomas Morawetz is the author of "Wittgenstein and Knowledge." He teaches contemporary legal theory at the University of Connecticut.