"What! Another of those damned, fat, square, thick books!" an exasperated Duke of Gloucester is supposed to have said to Edward Gibbon upon being presented Volume 2 of "The Decline and Fall of the Roman Empire." "Always scribble, scribble, scribble, eh, Mr. Gibbon!"

And all these years later, it's the same thing: Damned, square, thick books, scribbled by little Johnny Writer types, then turned into movies, and this fall appears to feature a shelfful of them. It's not even a trend, it's a simple reality. Just look: "Shopgirl," "The Chronicles of Narnia: The Lion, the Witch and the Wardrobe," "Memoirs of a Geisha," "Pride and Prejudice," "Everything Is Illuminated," "Harry Potter and the Flagon of Iced Gin," all due in the coming months. And there's at least a half-dozen more before Christmas. Good heavens, sirs, will you make a movie of anything? Have you no pride?

The answer is, no they don't have any pride. Hollywood is essentially a story maw; it gobbles up narrative from any source -- comic books have been big of late, '70s TV shows have become a staple, before that magazine articles, plays, myths, legends, songs even, all had their run as big source material. But the book, the novel particularly (though not always: "Black Hawk Down" and this year's "Jarhead," for example), has been a font of movies for seemingly ever.

I do not mean to inquire as to whether such a strategy makes sense, or what have been the best, the worst, the most indifferent literary adaptations. I don't mean to berate Hollywood for vulgarizing everything it touches and turning silk purses into sow's ears most of the time (they fixed "The Iliad" and called it "Troy," fixed it but good). We won't pick on them for remaking old stories without finding new stories. (Why does A.J. Quinnell's mediocre "Man on Fire" get two movie versions and George Pelecanos's superb "Hard Revolution" none?) We won't question a system that buys 10 times as many books as can ever be made into films, commissions five times as many scripts from those books as it can ever shoot, pushes them through rewrite after rewrite in an attempt to achieve the elusive balance of commercial elements, then inevitably picks the worst and makes a movie out of it. Those are all pathologies to be dealt with another time or, preferably, by someone else.

No, this is simply to answer small practical questions, to help all you puzzled movie consumers out there: Should you read the book before you see the movie? Does it matter if they change the book? If you know how it ends, what's the point in seeing it?

As a professional film critic for over three decades, I have firm policies on these important issues. But I have also sat in on story conferences (for books I've written that have never made it to production), and I understand, insofar as it is understandable, what the process entails. Thus I firmly believe that the answers to the foregoing are: Maybe. No. If you think this way, you're an idiot.

Do I have to read the book first? Hmmm. A tough one. My answer has mainly to do with the quality of the book in question. They seem to come in two flavors: literature and not. How can you tell them apart? Well, actually, nobody can, except for the New York Review of Books and maybe they're just guessing. However, the best way to make this decision is to look at the first sentence of the book.

"Call me Ishmael." Yes, you should read the book (not that anyone's going to make another version of "Moby-Dick"). Can you not instantly feel a shiver in the prose and understand that the writer has a command of the language that isn't a part of the book, it is the book. Melville: genius. The book isn't just a story expressed in symbolic blots of pattern known as words, it is somehow, gloriously, a fusion of words and story so that they are inseparable. It's a living thing. It's not about plot. It's about feeling, knowing, understanding the accursed vanities of yon twisted Ahab upon the foredeck, stumping and growling and radiant with blasphemy, and watching how the fanaticism of his scarred ego infects those about him until they believe unto death by whale violence. Gee, it's 150 years old, it's about a bunch of guys trying to stick spears in a nearly extinct sea creature who is, by genetic mischance, actually white; worse, they feel pretty damned proud of themselves for doing it, and it'll tell you more about today than any front page. If you've seen a movie of "Moby-Dick" and you know how it ends, you know nothing. Read the book. Now. Put this newspaper down and read the book.

On the other hand: "The VC-208 flight was somewhat lacking in amenities -- the food consisted of sandwiches and an undistinguished wine -- but the seats were comfortable and the ride smooth enough that everyone slept until the wheels and flaps came down at RAF Northholt, a military airfield just west of London." No, folks, you don't have to read the rest of Mr. Clancy's very fine "Rainbow Six" to conclude that for that distinguished gentleman, language is a medium by which facts are transported from his imagination to yours. Words are merely vehicles; they haven't meaning, weight, rhythm, sound, feel of their own or anything that resembles life. Thus you know that any movie drawn from them -- though the Tom Clancy films seem to have been back-burnered, as gung-ho service movies always are when actual and very unpleasant wars are being fought -- will be that same progression of known, catalogued entities, one after the other, and the book may be safely passed over in your hunger to get to a film experience full of stoical professionals, complex machinery and lots of stuff blowing up.

That all said, this is how it plays out over the next few months:

* "Shopgirl": Read the book. Steve Martin is always funny.

* "The Lion, the Witch and the Wardrobe": Read the book aloud to your kids. It will be good for them and you. If you don't have kids, you're off the hook.

* "Memoirs of a Geisha": You've already read the book.

* "Pride and Prejudice." If you've already read the book, so much the better. If you haven't and you're smart and young, you probably should read Miss Austen (and if your high school hasn't required it, find a new high school). If you're old and you haven't read the book, it's probably too late for you, as it is for me.

* "Everything Is Illuminated." I have no comment, but others do: "Inspired though uneven first novel." -- Publishers Weekly. "***1/2" -- Amazon.com.

* "Harry Potter and the Flagon of Iced Vodka": Everyone else has read the book, Rowling doesn't need your 7 cents, so you can skip this one.

At least three others are also scheduled, movie versions of Robert Penn Warren's "All the King's Men," Annie Proulx's "Brokeback Mountain" and, more obscure, Mark Spragg's "An Unfinished Life."

Now to another query: Does it matter if they change the book? The answer is, it doesn't matter if it matters, because, regardless, they're going to change it. They have to. Storytelling movie-style is different than storytelling prose-style. The primary issue in prose is motive: You have to understand why the people do what they do, or else the whole shebang falls apart as illusion. The minds of the characters have to be consistent to be believable; action has to flow from character. Fiction writing is about what happens internally, even if lots of guns come out and stuff blows up.

Movies don't have time for all that internal crap. They can't go inside, so what's the point? They can show only from a distance, and if people do things -- silly things, random things, violent things -- we still accept it because, well, we're seeing it. It's there, it's reality, we go with it. Then there are pressing commercial obligations: They have seven minutes to catch the attention of a 17-year-old boy whose brain has been fried by video games and who, when he's not lost in cyberspace, primarily wants to get high or laid, in no particular order. He is the key to their riches; he must be pandered to.

Therefore the movies usually have the freedom to pass on motive, or presuppose it. For people who learned story from fiction or old movies (a la moi), this is insanely irritating. But it doesn't matter what we think because there aren't enough of us anymore. What matters is spiking that boy's brain. Kick him in the head and you open No. 1 with over $50 million domestic BO. The action may be -- indeed almost certainly will be, by fiction standards -- arbitrary, unrooted, completely disingenuous, but that's not important; it has to grab hard and fast. So books have their longueurs taken out, their motives truncated, their characterizations reduced to primary colors (or black and white) and their action sequences ginned up, multiplied, amplified and made incandescent, movie-ized. Then everything is made tidy.

There are about a million cases in point, but let's just look at one of them. At the end of Charles Frazier's wonderful novel, "Cold Mountain," there's a furious shootout between hero Inman and Capt. Teague and his vigilantes. (Note: Spoiler Alert.) Inman kills all but one, then turns to face a punk kid who happens to be a mite faster. He kills Inman and rides off whooping to celebrate his victory.

I hated that. Sorry, Frazier, but I really hated that. Kill that damn kid! Shoot him in the guts! But I'm a melodramatist, Frazier a dramatist. Frazier had too much integrity for that and his view of the universe was tragic; he knew that the tidiness of melodrama had no equivalent in the real world. Messy is real, tidy is phony. Messy is literature, tidy is thriller. But not director Anthony Minghella in the movie version. He knew that for the unwashed, that damned kid had to die. Blammo! Inman blows him out of the saddle, the horse gallops off dragging his pitiful corpse behind. Even in an upscale product like "Cold Mountain," with its big-name cast and classy mounting, a note of barbaric ignorance triumphed. It's better Frazier's way, but it's cooler Minghella's way.

And that, finally, is the deepest truth of the book into the movie. That explains why, for lovers of the book, the movie almost never satisfies. Movies made from books aren't made for readers of the book -- even with a mega-success like "Cold Mountain," the prose-buying audience isn't big enough. Movies, then, are made for all the people who haven't read the book. Don't think of the movie as the book, it's more like an advertising flier from the book. It'll contain snatches, whispers, hints of what was, but in all other regards it'll be so much less complex, so much more turned toward anime. It's for a different part of the brain of a different kind of human being than the kind who likes to read books! That's not bad or good, it just is!

Thus the jiggering of "Cold Mountain" makes perfect sense. It's like Barry Levinson letting "The Natural" pound a boomer out of the park when, of course, the great American novelist Bernard Malamud, another with a tragic view of the universe, had struck him out in the original to the tune of "Say it ain't so, Roy." It's pointless to whine: Roy hits the boomer and Inman plugs the kid -- that is what movies do, that is what they are, that is how they work.

Finally, does reading the book first spoil the movie? The answer for the filmgoer is yes, the answer for the book reader is no. The filmgoer wants plot -- that is, outcome. If he knows what happens, the fun is gone; the book becomes just a collection of spoilers. Other than that, it's meaningless; it's just a part of the process by which that bright thing got up there on the screen.

For others (me, and at least seven or nine more) the movie is ephemeral, the book is real. Literature -- even simple craftsmanship -- is a higher art than filmmaking. The movie exists only when it's in the act of being projected; the book has the capacity to be savored. You cannot savor a movie. Ever stop a DVD at a particular moment that you love because you want to sustain the pleasure, at which point you realize that the single frame is nothing and has no magic? It's just a meaningless blur. It's not the movie. The book, however, may be reread and re-experienced almost infinitely; sentences, phrases, images can haunt you. I remember in John le Carre's "Tinker, Tailor, Soldier, Spy," spymaster George Smiley realizing something at "a speed which has no place in time." What a great evocation of the workings of the subconscious -- simple, elegant, precise. That phrase has never left me and I help myself to it at least three times a year, and get a little jolt of pleasure from my larceny. That's the sort of abiding pleasure books can give that movies can't, won't and never will.

Elijah Wood and Eugene Hutz in "Everything Is Illuminated," based on the Jonathan Safran Foer novel.Rupert Grint, Daniel Radcliffe and Emma Watson bring to life J.K. Rowling's fourth novel, "Harry Potter and the Goblet of Fire."Jane Austen's "Pride and Prejudice" gets yet another screen adaptation, with Keira Knightley and Matthew Macfadyen starring in the latest version.