Several years ago at a lawyer's club reception in Washington, I was witness at some distance to a legendary gesture. Standing in a conversational group, Justice Hugo Black drew from his coat pocket his famous pamphlet copy of the Constitution, pointing to one of its provisions as he spoke. It was easy for me to imagine that the great defender of the First Amendment was pointing to that simple provision: "Congress shall make no law . . . abridging the freedom of speech."

The direct terms of that prohibition must not be obscured by the excesses of zeal on both sides of the debate on the proposed ban on tobacco advertising.

The zeal may be that of good intention, as in the case of my friend, Rep. Mike Synar (D-Okla.), who proposes the ban along with Rep. Bob Whittaker (R-Kan.) or that of commercial interests such as Philip Morris' brochure with a copy of Pravda inside.

It must be kept clearly in mind that governmental attempts to limit commercial free speech can lead to measures as personally intrusive as attempts to limit political free speech. For that very reason, no words modify the term "free speech" in the First Amendment.

Let the fickle finger of public attention to tobacco-related issues, no matter how laudable, pass by without such damage to fundamental constitutional protections.

HENRY B. TALIAFERRO JR. Oklahoma City