The world of writers and books is often described, by those who inhabit it, as "a free marketplace of ideas," and ideally that is precisely what it should be: A place in which subjects and points of view, no matter how distasteful or even abhorrent, are available to all who seek them without censorship or other forms of restraint. But in actuality this little world is no more ideal than any other, and the censors go about their dirty business with unflagging zeal.

It's simple enough to identify those who do that business in public: The school boards that try to impose their own moral judgments on the education of the young, the librarians who remove "offensive" publications from the shelves they control, the politicians who attempt to repress ideologically disagreeable material. It may be easier to spot these people than to stop them, but at least their positions of public responsibility force them to be more or less open about what they do, and the sheer power of adverse publicity is often enough to limit the effectiveness of their labors.

But there are also censors who work in the dark, who limit the freedom of the marketplace in ways that can be extremely difficult to detect and whose power to influence the availability of reading matter--of ideas--can be considerable. It is a painful irony that some of these are people who, by virtue of their occupations, should be among the most trustworthy guardians of the marketplace: The people who sell books. As was made evident in a recent issue of Publishers Weekly, the book industry trade journal, some people who own bookstores have granted themselves the license to "avoid" stocking titles that they find distasteful for reasons of politics, taste or subject matter; "avoid" is a euphemism for "censor."

The magazine "conducted a survey to find out what subjects and titles independent booksellers deliberately avoid stocking within their stores; 38 booksellers responded." By contrast with the big chains--Crown, B. Dalton, Doubleday, Walden--these stores tend to be mom-and-pop operations in smallish communities; often the independent bookseller has the only genuine bookstore in town, apart from the drugstore and newsstand paperback racks, and thus is in a position to exercise disproportionate influence over what the locals read.

More often than not, that influence probably is exercised to benign effect. The independent bookseller usually knows his community far better than does the manager of a chain outlet, and has full authority to use that knowledge in order to buy books of local interest and appeal; indeed, the independent owner is famous in bookselling lore for knowing the individual tastes of his customers, many of whom rely on him to recommend titles they will like. Further, the bookseller has limited display space and cannot reasonably be expected to fill that space with books that he has little chance of selling to his particular clientele.

Thus it is difficult to argue with the Missouri bookseller who does not stock books about homosexuals ("offensive to most people in the area"), blacks ("almost no black people live in the area") or going back to nature ("They farm for a living and going back to doing it the hard, old-fashioned way is not appealing to them"). It may seem a narrow, homogenous sort of life out there, and it's too bad that local residents seem uninterested in buying books about people different from themselves, but this is the reality with which the bookseller has chosen to deal and it would be suicide to ignore it.

Nor can there be any reasonable quarrel with those booksellers who choose not to stock pornography, "the most frequently cited subject that dealers said they would deliberately avoid," at least so long as their definition of pornography does not embrace the mere mention of sex. Pornography may enjoy First Amendment protections, but those protections are generally contingent upon its careful removal from public display; in any event, since pornographic material is widely available by mail order or through stores that specialize in it, there can be no rational excuse for insisting that it be carried by the friendly neighborhood bookstore.

But sensible precautions designed to insure the stability of a bookstore as a business are one thing; an ordering policy that arranges a store's contents in order to suit the owner's ideological whim is quite another. There is, for example, the Montana bookseller who "avoids stocking what she calls right-wing propaganda, antifeminist books and racist titles on the grounds that they are 'offensive to us.' " Many booksellers said they "avoid" stocking books by persons who gained notoriety as a consequence of Watergate--doing their part, presumably, in the "don't-buy-books-by-crooks" movement. The article mentions one owner who "refuses to stock books on taxidermy, hunting and trapping (and will not special order them)" and another who "won't special order anything whatsoever, explaining that if she had decided not to stock a title initially, she wouldn't special order it either."

Presumably these people and all others who practice such forms of "avoidance" would agree with the bookseller who says: "I freely support my or any other merchant's right to choose that segment of the population he wishes to associate with in business. That I don't choose to stock books on drugs, terrorism and bombmaking does not mean I would restrain my neighbor from serving that segment I refuse. I retain my right to consider him a creep but not to put him in jail."

Poppycock. The argument about choosing one's customers is nothing except a variation on the old line that southern businessmen used to keep black customers out of their establishments, a line thoroughly discredited by court decisions and federal legislation; a business is a public enterprise and persons cannot be excluded from it because of race or personal beliefs. And in any event a bookstore is more than just another business, more than just a seller of competing brands of toothpaste or motor oil. A bookstore--unless it is one clearly identified as specializing in a certain kind of book or a certain ideological viewpoint--should be a place in which, like Alice's Restaurant, you can get anything you want.

The contents of a bookstore must be as diverse as the world of books; if they are not, because of the owner's deliberate decision to exclude certain ideologies or subjects, then it cannot accurately be called a bookstore. Running a real bookstore requires a belief in the importance of diverse opinion and the necessity of guaranteeing its free expression; the person who uses his store not to insure that diversity but to influence the views of his customers is not a bookseller at all, but a self-appointed censor.