I'm Nobody! Who are you? Are you - Nobody - Too?

If the quintessence of poetry is a kind of soliloquy or interior monologue, Emily Dickinson could well be considered poetry incarnate. Sometimes, indeed, she seems so absorbed in her own thought, it is hard to know quite what she is thinking.

Dickinson gave new meaning to the word concision in both her writing and her personal life. She retreated to her parents' house, and increasingly into the solitude of her own room. By the end of her life, she had even stopped visiting the home of her brother and sister-in-law next door. Although she sent poems to friends, allowed a few to be published, and sought out mentors for advice, for the most part she was content to consign the majority of her poems to handwritten, hand-sewn books that did not see the light of day till after her death in 1886.

A life so private, so reclusive, simultaneously invites and eludes speculation, particularly when it leaves in its wake a treasure trove of poems - over 1,700 - that are so richly crammed with meaning.

Who, we wonder, was the woman who could write poems as intense as "There's a certain Slant of light,/ Winter afternoons - / That oppresses, like the Heft/ Of Cathedral Tunes - " yet as playfully irreverent as "The Bible is an antique Volume - / Written by faded Men"? Who, if anyone, was the "Master" she sometimes addressed? Who, if anyone, was the object of her love poems?

Despite the assiduous efforts of critics and biographers, the answers to these questions may perhaps never be known for certain. And, in the final analysis, the answers, even if known, could never be as meaningful as the poems themselves.

Dickinson's latest biographer is Alfred Habegger, and the book he has produced is certainly a brick: 764 pages in length, the product of extensive and meticulous research into Dickinson, her forebears, local Amherst history, and the complicated cross-currents in 19th century American religion.

As he announces at the outset, Habegger wants to steer a course between the New Critical tendency to read Dickinson's poems without reference to biographical or historical contexts and the feminist-historicist tendency to emphasize the poet's life and circumstances. Filling in the context sheds light on her work, he believes, but her unique genius transcends context.

Habegger offers some surprisingly firm answers to the perennial Dickinson questions, although some of these answers do not really solve the essential mystery, particularly of her attitude toward religion. He sees her resistance to the kind of religious "conversion" that was then so popular not as a sign of agnosticism, but as part of her identification with her pious but unconverted father. But he does not give us a clear enough sense of what exactly "conversion" signified at the time and what might have led someone who was otherwise a believing Christian to balk at the process.

As for Dickinson's love life, Habegger sees definite links between her poems and specific men, such as minister Charles Wadsworth and editor Samuel Bowles. Although he knows of her intense feelings for her sister-in-law, Sue Gilbert, and for other women friends, Habegger does not regard her as a lesbian.

Toward the end of her life, Habegger writes, Dickinson had a genuine and requited love affair with the formidably stern judge Otis Phillips Lord, whose spiteful and censorious niece, years later, recalled the poet as a "hussy."

Habegger's Dickinson is a loyal, intense, quirky, affectionate woman who has a hard time finding friends who feel as strongly about her as she does about them. Habegger sees her gradual retreat from the world as a way of accommodating the beliefs of her father, whose views about the role of women were old-fashioned even for the time. Dickinson once wrote of her father, "He buys me many books - but begs me not to read them - because he fears they joggle the Mind."

Habegger argues that Dickinson identified the life of the mind with the male presences in her life: Rather than rebel against patriarchy as some feminists of her day were doing, she sought out male mentors. Rather than challenge her father, she retreated to a domestic role looking after both her parents. But within that physically constrained space, she permitted herself a limitless imaginative, intellectual, and emotional freedom.

One of Habegger's most valuable contributions is his thesis that Dickinson continued to develop as a poet over the three and a half decades of her adult life, gaining insight and wisdom as she pursued her intellectual "warfare," that strenuous and fruitful argument with herself.

Merle Rubin reviews books regularly for the Monitor.

By Alfred Habegger Random House 764 pp., $35