Any writer who has something to say about the literary impact of drugs should have the common decency to establish his credentials for doing so. In my case, I should say that I graduated from Berkeley in 1967, and when I was there, a state representative stood up on the floor of the California State Assembly and said, quite accurately, when you get down to cases, that "A four-year education at Berkeley is a course in sex, drugs and treason."

So, I think it is safe to say that I have had some experience along these lines, not the treason part, and not as much of the sex part as I'd like, but about as much of the drug part as anyone can take and still remember what actually happened.

Now, I have known a fair number of writers over the years, and a lot of them have taken drugs, but it wasn't until I read The Road of Excess, A History of Writers on Drugs (Harvard University Press, 320 pages, $29.95) that a theory began to coalesce out of the literary-psychological mists. It is a theory, I now realize, that explains a lot of what has troubled me about some writers I have known and some I have been fortunate enough only to read about.

It is this. Writers, as a group, are impossibly stupid, particularly when it comes to believing that the unknown, the untried and the faddish impulses of the moment are better, more true and generally more illuminating than the known, the certain and the difficult. When Marcel Duchamp wanted to say that someone was stupid, he said that this person was as "stupid as a painter." The Road of Excess has proved him wrong. Where the belief in easy enlightenment is concerned, it should be as "stupid as a writer."

Academic writers are often good at doing research, but not so skilled at making sense of it, and a poor combination is the inept academic writer who hides behind academic jargon. The dead giveaway for such a writer is that he doesn't have any "simple answer," and that he is going to let the "facts speak for themselves," which means, when translated into ordinary, nonacademic English, that the writer has done some interesting research and doesn't really have a clue beyond that.

This is the case of Marcus Boon, the author of The Road of Excess. I know it is hard to believe, but this is what he has to say for himself. "Those who read this book hoping for a neatly packaged answer to 'the drug problem,' or a clever all-encompassing theory about the relationship between drugs and literature, will be disappointed. The whole weight of my argument consists in separating drugs from each other, showing how each has a quite specific historically emergent discourse attached to it, and avoiding theoretical generalizations on the subject that reify precisely what they claim to dissipate through the supposed illumination of conceptualization."

That's what I call writin'.

Still, Boon does shine in doing research, and he has done an exceedingly thorough job of giving the reader the details of the history of drug use. Coleridge, De Quincey and all of the greats are here, along with some details that have eluded the general reader. For instance, I didn't know that De Quincey had hired a man to "block his entry into any chemist's shop that he might attempt to visit."

Of course there is Baudelaire, taking opium for his "depression, various pains, syphilis, pleasure." I also learned of the existence of Alexander Wood, who was the first one to use a syringe to inject morphine, with the effect of making his wife into the first "injected morphine addict."

As far as the literary impact of drugs is concerned, the two that stand out are nitrous oxide and opium. The Romantics, of course, were sitting ducks for opium, if only because, as Boon points out, the Romantics had a fascination with what Edmund Burke called the sublime, which was "pleasure taken in abysses" and "murky darkness."

What can compare with the thrill of gloom, especially one enjoyed at a distance? And what is more thrillingly gloomy than the world of the opium smoker, at once so pleasurable and so remote from life? The Romantics in a nutshell.

Opium, I suppose, is a more forgivable indulgence than some of the others that followed, but the drug that really showed writers as giants in the fuzzy-thinking department is the case of nitrous oxide, which was tailor-made for the transcendentalists and other American investigators of the spiritual life, such as William James. James wrote of nitrous oxide that, "with me, as with every other person of whom I have heard, the keynote of the experience is the tremendously exciting sense of intense metaphysical illumination. The truth lies open to view."

Of course, the impulse to bring back this "open truth" was strong, and yet, much to the dismay of the people who tried to do so, it was impossible. Oliver Wendell Holmes thought that the way to go about retrieving this truth was to get loaded on ether and then to write down, the instant he came to his senses, what the nature of the profound illumination was. When Holmes did this, he wrote, "A strong sense of turpentine prevails throughout." When Oscar Wilde tried it, the master of wit came up with, "That would have been a tough job without the elevator."

And, while looking into The Road of Excess, I ran across something called White Lines (Thunder's Mouth Press, 352 pages, $16.95), which is a collection of excerpts about cocaine. Now, as hard as it is to believe, White Lines proves that all coke stories are the same, which is to say, they are a compendium of self-loathing and gallows humor, and the only one among the many writers included here who has his head screwed on right about coke is Stephen King. As he says, "The idea that creative endeavor and mind-altering substances are entwined is one of the great pop-intellectual myths of our time." I suppose it takes someone with a keen sense of horror to look this truth in the face.

There are other examples of foolishness in The Road of Excess, some of them distressingly modern, such as the use of LSD and the like in the Sixties. The question is, what makes the belief in drugs as enlightenment so silly? I suppose it has to do with the attempt to experience the otherworldly and the spiritual through chemistry, which is at once materialistic and mundane. And, if one is going to insist on the Stupidity Factor where writers are concerned, it is this: If you are going to get a snootful, it isn't a good idea to think that you are in touch with wisdom and cosmic understanding. If taking a pill were really the way to enlightenment, what do we need writers for? We can take the pill ourselves. And, of course, end up trying to live our lives on the basis of the pervading scent of turpentine.

Craig Nova is the author of 10 novels, including The Good Son, Tornado Alley and Wetware, which was published last January. His Brook Trout and the Writing Life was published in 1999. He is at work on a new book and on a screen adaptation of The Good Son.