There are no half measures to Kay Redfield Jamison’s medico-biographical study of poet Robert Lowell. It is impassioned, intellectually thrilling and often beautifully written, despite being repetitive and overlong: A little too much would seem to be just enough for Jamison.

"Robert Lowell, Setting the River on Fire: A Study of Genius, Mania, and Character," by Kay Redfield Jamison (Knopf)

Nonetheless, “Robert Lowell: Setting the River on Fire” achieves a magnificence and intensity — dare one say a manic brilliance? — that sets it apart from more temperate and orderly biographies. Above all, the book demands that readers seriously engage with its arguments, while also prodding them to reexamine their own beliefs about art, madness and moral responsibility. Reading this analysis of “genius, mania, and character” is an exhilarating experience.

From the late 1940s to the mid-1970s, Lowell was the most admired and talked-about American poet of his generation. Scion of a privileged New England family, he counted among many distinguished ancestors two notable poets — James Russell Lowell and Amy Lowell — as well as Percival Lowell, the astronomer who sighted what he thought were canals on Mars.

Prodigiously gifted, Lowell won his first Pulitzer Prize in 1947 for “Lord Weary’s Castle” — which includes the famous long poem “The Quaker Graveyard in Nantucket” — and still another in 1974 for “The Dolphin.” At least as important, though, is “Life Studies” (1959), which established a confessional style that would long dominate American poetry. In 1977, at the young age of 60, Lowell died suddenly of a heart attack while taking a taxi from the airport to the New York apartment of his former wife, the novelist and critic Elizabeth Hardwick.

According to Hardwick and others who knew him, Lowell was — most of the time — kindly, witty and loving. Unfortunately, along with all the advantages of being born into American aristocracy, the poet also inherited a manic-depressive illness that would wreak havoc in his life and cause an immense amount of pain to his family and friends. Periodically — 16 times or more during his adult life — his entire being would accelerate, shift into hyperdrive. He would inaugurate affairs with young women, spit out torrents of hurtful abuse, grow physically violent and delusional, and sometimes identify himself with Napoleon or even Hitler.

It might take a half-dozen burly policemen to subdue the over-revved Lowell, so that he might be taken away for care at McLean Hospital or Payne Whitney Clinic. There he would be given drugs or psychotherapy, both usually ineffective, or more usefully electroconvulsive shock treatments. Only in 1967 did physicians begin to prescribe lithium to control his manic depression. Because of it, Lowell would successfully manage his demons for the last decade of his life, except when he neglected to take the lithium or took too much of it.

Throughout her book, Jamison views Lowell’s strength of character as nothing less than herculean, as he reestablishes his life, again and again, after each shame-filled, soul-killing episode of insanity. She also explores the probable clinical link between mania, which can free up the inner self’s mind-forged manacles, and artistic creativity. As Shakespeare wrote long ago, “the lunatic, the poet, and the lover/ Are of imagination all compact.” In the case of Lowell, who was all three of these, Jamison contends that “instability and the relentless recurrence of his illness hardened his discipline while mania impelled and stamped his work.”

Robert Lowell in 1947 (The Associated Press)

To establish her diagnosis, this distinguished professor of psychiatry at the Johns Hopkins School of Medicine and author of the best-selling memoir “An Unquiet Mind” brings to bear everything she can think of. Jamison piles on a multitude of quotes attesting to Lowell’s great genius, perhaps because the poet’s reputation has diminished since his death. Like a modern Robert Burton, she digresses into an anatomy of manic depression — she feels that the contemporary term “bipolar disorder” sanitizes the horrors of this illness — and describes the kinds of treatment available in the past to the mentally disturbed.

Alongside photographs of Lowell and some of the people he loved, she reproduces his medical charts and records, having been granted special access by the poet’s daughter and executor. She also regularly underscores her points by citing Lowell’s poems, concluding her book with an extended tribute to “For the Union Dead,” that majestic meditation on history, race and valor.

“Robert Lowell: Setting the River on Fire” would be an unqualified triumph were it not for Jamison’s penchant for overkill: Everything is treated a bit too expansively, many points and anecdotes are repeated twice or three times, and rather than quoting one authority, she quotes a half-dozen. While Jamison’s prose, like her thought, always remains admirably clear and often striking, she’s inordinately fond of declamatory effects — “New England would be a light, a beacon, a spirit and an exemplar” — and she noticeably favors the heavy melodrama of serial modifiers and nouns: “Ancestry is preordaining, corrupting, benevolent, benign, damning.”

Above all, though, Jamison’s book is as much an apologia as it is a clinical analysis. The French say “tout comprendre, c’est tout pardonner”— to understand all is to forgive all. Jamison recognizes that Lowell damaged other people’s lives, but she excuses him because he really had no control over his behavior. Still, who speaks for all the young women he seduced with promises of love and marriage, then dropped? And who paid for all those expensive hospital stays? Lowell got away with a lot. Jamison concludes that great poetry even justifies the humiliation he consciously inflicted on Hardwick by printing her anguished private letters in “The Dolphin.” As Elizabeth Bishop angrily told him, “Art just isn’t worth that much.”

Or is it? Certainly, “Robert Lowell: Setting the River on Fire” is a book to be learned from and argued with. It is both empathetic and astute, as heartfelt as it is heartbreaking.

Michael Dirda reviews books on Thursday in Style.

On March 2 at 7 p.m., Kay Redfield Jamison will be at Politics and Prose Bookstore, 5015 Connecticut Ave. NW.

robert lowell
Setting the River on Fire
A Study of Genius, Mania, and Character

By Kay Redfield Jamison

Knopf. 532 pp. $29.95