(FORTUNE Magazine) – We open with three gripping flashbacks: Scene One: A class in formal logic at New York University. Time: 1945. Philosopher Sidney Hook is telling the class that the tu quoque argument -- in which you charge an adversary with being or doing what he criticizes in others -- is logically fallacious but occasionally irresistible. Among those taking notes is a juvenile version of the present writer. Scene Two: Someplace in Washington, D.C. Time: 1983. Superliberal Senator Howard Metzenbaum learns that super-rich investor David Murdock would like to buy the elegant old Hay Adams hotel. The Senator, who happens to know the owner, makes two fast phone calls, then collects a $250,000 finder's fee when the hotel is sold. When all this is later publicized, Howard says senatorial ethics or something requires him to return the fee, as ''reality and perception can be easily confused.'' Scene Three: The Keeping Up Library. Time: December 1990. A senior policy analyst is hooting and snorting as he scans the transcript of recent Senate hearings on a suddenly contentious new issue in labor law. The issue: Should business be allowed, as it has been for the past half century, to permanently replace workers who walk off the job? Presiding over the hearings: Howard Metzenbaum. He and the AFL-CIO naturally wish to change the law, and Howard gives a hard time to the committee's final witness, a fellow from International Paper. The Senator says he is surprised and disappointed that a fine, upstanding company like IP would hire permanent replacements in a - strike. He says he expects such foul deeds to be done only by characters ''who just come in for that fast buck.'' Irresistible, eh?

The strike at the New York Daily News -- in which many striking workers have now been permanently replaced -- has obviously led a lot of union sympathizers to focus hard on the existing law. In writing about the Daily News contretemps last fortnight, we expressed astonishment at the deafening silence of Gotham's liberal establishment in the face of Mafia-like intimidation of the paper's vendors and distributors. Since we wrote, the establishment has found its voice. Unfortunately, its only message seems to be the urgent need for S.2112, which is Metzenbaum's bill to outlaw permanent replacement of strikers. Among those calling for the change: Governor Mario Cuomo, Jesse Jackson, and John Cardinal O'Connor. The cardinal says he is not on either side in the Daily News strike, but he recently appeared at a strikers' rally and later told the Metzenbaum committee the present law is ''immoral,'' so we are sadly counting him on the side of the guys with the baseball bats. Present law is often called the MacKay Doctrine, because it derives from a 1938 Supreme Court decision involving MacKay Radio & Telegraph Co. The decision, taken together with others following on it, interpreted the National Labor Relations Act to mean the following: First, companies are free to offer permanent jobs to workers who replace strikers. Second, however, this freedom assumes that the strike is over economic issues; if it was precipitated by an employer's unfair labor practice, then the strikers would retain their job rights. Third, they would also retain these rights if the company never tried to operate during the strike. Taken together, that cluster of rules does not seem excessively unfair to the labor monopolists screaming about it. In any case, why change it now, after half a century -- a period in which Democrat-controlle d Congresses have repeatedly turned back efforts to overthrow MacKay? The answer endlessly provided in the Metzenbaum hearings is that the law used to be innocuous because employers did not use it. It was only in the greed-ridden Eighties, the argument goes, and especially after Ron replaced air-traffic controllers who had struck against the government, that employers began turning to MacKay. It could be that the unions and their numerous congressional allies -- 20 Senators and 189 House members have thus far co-sponsored the legislation -- are making a large mistake in pounding home this argument. Data collected by the General Accounting Office show that, even today, only a small minority of companies attempt to permanently replace strikers; in 1989, for example, it happened in only 15% of strikes. The great majority of strikers do in fact get their jobs back. In overstating the prevalence of MacKay tactics, the unions run the risk that employers really will begin to decide that Reagan had it exactly right. And conclude that the MacKay approach is ordinarily quite moral.