THE ETHICIST TAP : [ A ]

RIGHTS come with rationales. We don't want to remove controversial books from public libraries, because we have an ideal of a society where adults make their own choices about what to read.

People will decide to read things that would be deplored by literary critics or anti-smut campaigners or religious clerics or card-carrying rationalists.

Some people's views, inevitably, will be shaped by wrongheaded ideas. That's a bad thing, but ruling out that possibility would involve giving someone else the authority to make these decisions, which would be worse.

It's also true that, historically, magistrates and decency commissions have been curiously unworried that they themselves would be corrupted by work that, they judged, would corrupt others.

A British prosecutor, urging a jury in 1960 to find a paperback edition of ''Lady Chatterley's Lover '' obscene, notoriously asked, ''Is it a book that you would even wish your wife or servant to read?'' But it's not silly to ask whether a book is one you would want your children to read.

Parents properly supervise the reading of the young children.

Still, I see no problem in letting your child read books that get up your nose; children are often drawn to books that feel transgressive. Besides, learning literary discrimination requires exposure to a range of materials.

The real issue here is his tendency to forget his manners after reading these books that he likes and you loathe.

If you don't like his talk, by all means show your disapproval. But there's the basis for a deal here. You let him read about stinky butts if he'll stop talking about them so much.

The World Students Society thanks Professor Kwame Anthony Appiah, who teaches philosophy at N.Y.U. His books include '' Cosmopolitanism, '' ''The Honour Code '' and '' The Lies That Bind : Rethinking Identity.''