A MARXIST PROFESSOR seeking a job at the University of Maryland was the subject of an Evans and Novak column in 1978. Among other things, the columnists wrote that the professor, Bertell Ollman, "has no status within the profession, but is a pure and simple activist." Professor Ollman sued for libel, and on Tuesday, the Supreme Court let stand a Court of Appeals decision that the statement was an expression of opinion entitled to absolute First Amendment protection.

Statements of fact and expressions of opinion are treated differently by the courts, with the latter being given far greater latitude. In 1974, for example, the Supreme Court ruled that "Under the First Amendment there is no such thing as a false idea. However pernicious an opinion may seem, we depend fr its correction not on the conscience of judges and juries but on the competition of other ideas." The difficulty has always been in determining when a statement is fact and when it is opinion. "My brother-in-law is a crook" illustrates the problem. So does "The speaker has a fascist mentality." But most of us understand such statements as hyperbole and not necessarily intended as factually correct.

Judge Kenneth Starr, writing the lead opinion for the widely divided Court of Appeals in the Ollman case last December, set out a test for distinguishing between fact and opinion for purposes of libel. Even a statement that appears to be fact, he wrote, is opinion if 1) the term used cannot be precisely defined; 2) the statement cannot objectively be proved or disproved; 3) in context, the words are intended as opinion; and 4) by custom or convention, the statement is of the kind normally understood as opinion. Using this test, it is apparent that the illustrations above differ markedly from saying "My brother-in-law served six years in Lorton for a 1976 armed robbery" and "The speaker was in Hitler's cabinet and told me that he would do it all over again." Judge Robert Bork, who filed a concurring opinion, thought that even these standards were too rigid. The test for judges, he wrote, is to consider "the totality of the circumstances that provide the context in which the statement occurs and which determine both its meaning and the extent to which making it actionable would burden freedom of speech or press."

The Ollman case had a particular complication because the alleged libel went to the man's professional ability. In common law, defamatory statements on such matters are considered especially serious, and no proof of specific damage is required. Five judges on the Court of Appeals were persuaded that the case should have gone on to trial, and Chief Justice Burger and Justice Rehnquist cited common law in dissenting from the court's decision not to hear the case.

Readers of editorials, op-ed articles and the letters of rebuttal they both generate know that these deal in both fact and opinion. Any responsible newspaper will try to ensure the truth of what it prints without stifling the varied and contentious opinions that are presented. The views, ideas and criticism that appear on such pages are, we hope and believe, essential to political debate and informed self-government. The Court of Appeals has protected your right to read, evaluate and participate in this discourse, and the Supreme Court was right to let that judgment stand.