Can journalists really tell the ‘truth?’

What took them so long? The Lifespan of a Fact has all the answers, and at the same time, none of them. The book, which credits D’Agata and Fingal as co-authors, chronicles years of correspondence between the two men, as one reviewed the other’s facts and found, again and again, discrepancies and hearsay that strayed far from what most would expect from so-called “nonfiction.”

This may all sound a bit dense and theoretical. But The Lifespan of a Fact needn’t only be read for the intellectual debate it offers about authenticity in storytelling. You could, hypothetically, ignore all of that baggage and focus on the upsetting, engaging story being told of a dramatic suicide in Las Vegas. If you like compelling, emotional stories set in wild, business-friendly locales, this book delivers. And it’s actually fun to see the editorial process behind a long work of journalism stripped bare, although you’ll enjoy this book a lot more if you can accept that the debate between its co-authors will not be satisfyingly resolved.

The book is quite dense in its presentation. In a small block on each page we see text from the original magazine article, surrounded by Fingal’s notes and D’Agata’s responses to them. The notes are colored vivid red in cases where Fingal found problems with the text, or black when D’Agata’s facts checked out (more rare). The best route is to go through and read the original piece first, on its own, then go back and read the notes.

The article itself is an interesting and well-told meditation on the circumstances of Presley’s death and its larger implications. And there’s lots of great detail about the Vegas business scene, where gaming moguls like The Stratosphere’s Bob Stupak (or Steve Wynn and Sheldon Adelson, names that may be more readily recognizable to Fortune readers) vie to create over-the-top attractions for big-spending guests.

D’Agata notes that The Stratosphere has been named “Ugliest Las Vegas Building” and “Trashiest Place in Vegas.” (It cost $550 million to build and quickly accumulated $887 million in debt.) He provides compelling numbers about suicides, varieties of death, and other grim indicators associated with the hotel and with Vegas at large.

But Fingal quickly finds that many of D’Agata’s numbers are incorrect or fudged. After enjoying the main story and then discovering its many untruths in the notes, you might feel outraged or indifferent, depending on whether you think D’Agata’s loose allegiance to facts actually matters. D’Agata’s attitude is clear from the very first response he gives when Fingal contacts him: “Hi, Jim. I think there’s maybe some sort of miscommunication, because the ‘article,’ as you call it, is fine. It shouldn’t need a fact-checker.”

Oh, but it does. When Fingal discovers there are 31 strip clubs in Vegas, not 34 as D’Agata has written, D’Agata responds, “The rhythm of 34 works better in the sentence than the rhythm of 31.” Yes, the statement is ridiculous, but D’Agata isn’t the only self-important voice in the room. Fingal lavishes neurotic attention on details that most fact-checkers wouldn’t feel need to be checked, or would at least recognize cannot be.

For example: D’Agata cites a “rumor” that there was originally a tiny kink in one of The Stratosphere’s towers. Fingal asks for the source. D’Agata responds that a bus driver/tour guide said it in 1994, when he was on a Vegas trip as a sophomore in college. Though every publication has a different editorial process, most factcheckers would accept this anecdotal detail as just that — an unverifiable anecdote. Not Fingal, who requests the name of the tour company and D’Agata’s notes from that trip. D’Agata possesses neither of them.

Fingal also quibbles when D’Agata quotes a police officer saying, “None of this is gonna sound like a Mickey Spillane novel. You know?” In D’Agata’s notebook the quote reads: “It’s not going to sound like a Mickey Spillane novel.” The exchange will help you discover your own threshold of permissibility in terms of altering quotes. But it’s hard not to agree when D’Agata responds reasonably, “I punched up his statement, but I think the basic gist is the same.”

Lifespan has already stirred controversy in the literary world. At the Book Bench blog, a New Yorker fact-checker sides entirely with Fingal and contends that D’Agata’s worldview is “delusional,” adding that he “fails to realize … these liberties are indeed harmful.” Over at Salon, Laura Miller takes issue with both authors, describing the book as a “pissing match” full of “dickish replies.” Miller aptly notes that the entire situation could have been resolved by adding an editor’s note to D’Agata’s article saying that the piece “contains factual material but is not restricted to factual material.” But then there would have been no book.

David Shields, author of Reality Hunger and a writer at the forefront of a literary movement that seeks to destroy genre definitions like “memoir” and “nonfiction,” gives a highfalutin’ blurb for the book in which he praises D’Agata’s “vision of the slippery nature of existence, the deep unknowability of things, the beautiful facticity of ‘nonfiction’ and the fictionality of ‘fact.’” But this book doesn’t necessarily need to be read as a high-concept manifesto. And it’s unlikely to instigate sweeping changes in the practice of journalism: Every publication out there will likely continue to operate under its own editorial parameters.

Media professionals can be expected to read the book as a provocative, perhaps gimmicky statement on the ethical dilemmas inherent in producing a work of nonfiction. But the rest of the reading public may not feel a need to probe these questions. Indeed, it’s quite possible to enjoy this book simply as an amusing, testosterone-flooded argument between two men who would both rather see the story killed than bend to the other’s way of thinking. And furthermore, what is packaged as an erudite, ethical debate is also, more simply, a facetious performance built specifically to provoke.

Appropriately for a book about the line between fact and fiction, D’Agata and Fingal have obviously modified bits of their exchanges to amp up the comedy — the two of them are too snarky and rude to each other too quickly for it to have been the real exchange.

Case in point: D’Agata speculates that as Presley rode up in The Stratosphere’s elevator, a fellow rider “might have interrupted the operator to ask … while giggling, how many times each day she goes up and down the shaft.” Fingal responds bitterly: “No proof of this in John’s notes, but everyone loves a good dick joke, so I’ll let it pass.”

“This is getting nowhere,” Fingal grouses after a predictably heated debate about the essay’s larger implications. D’Agata responds: “You feel misled by my essay. I accept that … We disagree. I’m OK with that. But I’m also not sure where else to go.” He then bows out, giving Fingal the last word. In the end the factchecker very nearly comes around to D’Agata’s point of view, asking: “Even if everything that’s in question could be verified by unbiased third-party witnesses, and even if I could definitively determine to a fraction of a second exactly when it was that Levi left his house and from how high it was that he jumped … I’d have done my job. But wouldn’t he still be dead?”