By its decisions last week in three obscenity cases, the Supreme Court showed itself to be divided and sorely confused over the delicate question of censorship. It reversed the Massachusetts ban on Fanny Hill in a 6 to 3 decision and affirmed the conviction of Edward Mishkin, a publisher of "obscene" material, in another six to three vote. But the key case was a five to four decision upholding the conviction of Ralph Ginzberg, founder and publisher of Eros magazine. The right of the Supreme Court, or any other court for that matter, to enforce censorship is uncertain at best, but the indication of last week's decisions, as Justice John Harlan himself pointed out, "is that no stable approach to the obscenity problem has yet been devised by this Court."

The Ginzberg case is the most significant, for it demonstrates clearly the contortions the Justices are undergoing as they try to determine how much protection the public needs from men who write dirty books. Ginzberg had been indicted in 1962 for distributing through the mail a slick-paper, hard-cover glorification of sex called Eros. He was sentenced to five years in jail and fined $28,000.

The Supreme Court upheld the conviction, but Justice William Brennan Jr.'s majority opinion is puzzling indeed. Brennan explained that the Court could use a publisher's manner of advertising to determine whether the material itself is obscene. A publication with some kind of "redeeming social value" may escape the obscenity charge. But Brennan seemed to be saying that titillating publicity establishes the obscenity of a book's content. When the material's status is uncertain by other tests, the advertising criterion may tip the scale in favor of labelling the publication obscene.

But the way in which a publication is advertised does not affect its content. The other tests for obscenity, that the work appeals to "prurient interests," that it is "patently offensive," and that it is "without redeeming social value," all refer directly to the substance of the material. But the advertising criterion is a tacit admission by the Court that it cannot draw a clear distinction between a work that is obscene and one that is not on the strength of the material itself. If a book is not "patently offensive," how can the way in which it is publicized make it so? The advertising test implies that a book published with a lurid cover and titillating publicity is obscene, but that the same book, without the buildup and the come-on, is acceptable.

The Court is sending Ginzberg to prison for five years for touting his periodical as erotic. But Ginzberg was not charged with salacious advertising; he was charged with publishing obscene material. The Court should not have affirmed the conviction by invoking an entirely new standard to decide the case. As Justice Potter Stewart said in a dissent, "Neither the statute under which Ginzberg was convicted nor any other Federal statute I know of makes 'commercial exploitation' or 'pandering' or 'titillation' a criminal offense."

The Ginzberg decision indicates that the Court has failed utterly to establish clear guidelines in obscenity cases or to agree on a definition of obscenity. Justice William O. Douglas dissented by attacking the advertising test, Justice Hugo Black by defending a broad application of free speech, and Stewart by a strict application of the Constitution and the First Amendment.

The confusion means that lower court judges will have no clear legal yardstick on which to decide censorship cases, and their determinations will reflect their own sensibilities more than the dictates of the law. Convictions will become even even more capricious than Ginzberg's. Defense attorneys will be unable to prepare their cases because they will not know which criteria the judge will employ. The Supreme Court should be clarifying the law, but in last week's decisions, it only scrambled it. The decisions have gone a long way toward confirming doubts about a court's ability to censor what the public reads and sees.