Marilyn Monroe: For most Americans in the second half of the 20th century, the name alone was a sentence. She was Venus, beamed into still photographs and onto movie screens directly from the Milky Way — vulnerable and childlike and, when she wanted to be, achingly funny, with goodness knows what darker qualities in reserve.

Other models and movie stars more closely approached physical perfection, with more symmetrical facial features (Gene Tierney), longer legs (Juliet Prowse), more stylish physiques (Audrey Hepburn) or more exquisite rear ends (Brigitte Bardot). Physically, though, Monroe — five-foot-six, a size 5 when she was in her best shape, singing “Happy Birthday” to JFK on national TV — enjoyed a couple of unique perfections.

Her breasts? Well, yes, they were beautiful, and, although nowhere near as large as, say, Marie Wilson’s, they did something unusual: The muscles beneath them gave them an upward tilt that seemed almost anti-gravitational. Yet, in terms of Monroe’s physical endowments, the pair I was thinking of were her mouth — which, in photographs, evokes a countless variety of emotive responses — and her intrinsic glow, a property of her skin, on which many of those who photographed and filmed her remarked with wonder.

But what made Monroe a goddess wasn’t her body per se: It was the alchemical process between her body and what, consciously and unconsciously, animated her from within. After she died, 50 years ago today, at the age of 36, under circumstances that are still inconclusive, the alchemy was reduced to mere chemistry: a toxic overdose of barbiturates and chloral hydrate, deemed a probable suicide at the time by official sources but, in the decades since, considered an accident — or even murder — by prominent biographers.

According to one of the biographers here — the British pop-culture chronicler Keith Badman, whose “Marilyn Monroe: The Final Years” was first published in England in 2010 — nearly 700 books about (and by) Monroe have appeared so far, a formidable pack for any new biographer to confront. Badman peppers his prose with sentences that begin “I can reveal” but fails to support them with a bibliography or a single footnote. He offers a sort of countdown clock to Monroe’s demise, going minute by minute the closer it gets to the end (Badman actually compares himself to Sherlock Holmes), and thus his biography seems merely sensational for its first half. Indeed, the other biographer here, Lois Banner, a distinguished professor of history and gender studies, dismisses Badman’s book out of hand for its lack of scholarly apparatus in a footnote of her own new book, “Marilyn: The Passion and the Paradox.”

‘Marilyn Monroe: The Final Years’ by Keith Badman (Thomas Dunne)

Badman could have obtained some of his information — specific times; specific sums for expenditures; specific knowledge of the hour-by-hour whereabouts of John and Robert Kennedy, rumored to be Monroe’s lovers and, for some speculators, involved in ordering her death, possibly by a drug-laden enema — only from documents whose sources he manages to hide. These might include police reports, transcripts of phone conversations (Monroe’s phone was apparently double-bugged by the FBI and the mobster Sam Giancana) and presidential papers, but the reader can only guess. To understand why he’s written his book, you have to read to the very last page: “I seriously hope that, some day, the charge of ‘probable suicide’ on [Monroe’s] death certificate [will] be changed to simply, ‘accident’. She deserves this. She has not earned the stigma which suicide brings.”

However, along the way he takes some mighty swipes at the reputations of JFK, whom everyone agrees had a one-night stand with Monroe at Bing Crosby’s house; Robert Kennedy, whom Badman, proverbially holding his nose, lets off the hook from both the charges of having an affair with Monroe and being complicit in her death; Monroe’s last psychiatrist, Ralph Greenson; the actor Peter Lawford; and the suits in the front office of Twentieth Century-Fox, among others. His hero is baseball icon Joe DiMaggio, the second of Monroe’s three husbands and the only one to attend her funeral and never to write a confessional book or give interviews about the actress.

Banner’s ambition is much larger — to consider the living Monroe as a whole person: an unusually imaginative and loving child; a sufferer for nearly her entire life of a pronounced stammer, which made public speaking onerous, and of an array of other physical ailments; a victim of childhood abandonment by her parents, of a murder attempt by her insane mother and of pedophiliac molestation, if not rape; a survivor of many foster homes, which Banner has tracked down. She was also a largely self-taught connoisseur of art and photography; an earnest student of Method acting; a reader of the 16th-century anatomist and author Vesalius, Freud, Lincoln Steffens, I.F. Stone, Willa Cather and of poetry by, among others, her friend Carl Sandburg; a student of dancing with Lotte Goslar, Jack Cole and Gwen Verdon; a woman known for her kindness and generosity; a libertine who longed to be an artist; and, perhaps most unusual, a person with an intensely spiritual side.

Despite its elaborately psychoanalytic perspective — whose speculations as to motives and feelings are sometimes highly questionable (Banner takes Dr. Greenson’s part) — this is the book to read if you want to try to understand what made Monroe tick. Where Badman’s book took five years to produce, Banner’s took 10; and, although their background readings seem to overlap in places, Banner keeps asking questions and weighing evidence long after Badman has settled for his eureka revelations. Banner’s methodical approach and refusal to give Monroe praise when the actress doesn’t deserve it confer a kind of dignity on the subject that Badman’s book doesn’t.

Unfortunately, both books could have used more stringent proofreading and copy-editing, as well as a crackerjack overall editor who would point out contradictory statements and perform careful line editing. The cover photographs for each, though, are exactly appropriate to their respective texts and independently wonderful.

Mindy Aloff is the author of “Hippo in a Tutu: Dancing in Disney Animation.”


The Final Years

By Keith Badman

Thomas Dunne/St. Martin’s. 340 pp. $25.99


The Passion and the Paradox

By Lois Banner

Bloomsbury. 515 pp. $30