In the same breath in which the world learned about murder by cyanide-laced Tylenol, it also learned what sort of person did it: a madman. Such has been our progress since the Middle Ages. When unexplained tragedy struck then, people were no less able and ready to account for it: the witches did it! The Jews did it! It doesn't matter that such explanations are not true, do not explain and even impede the genuine understanding and rational solution of the problem.

The mass mind is like the child's. It cannot bear unexplained events that frighten it. Since it lacks the means for rational understanding, it "explains" by means of fantasized images and magical incantations.

Presumably, no one knows who is responsible for the Tylenol murders or why he or she has done these deeds. Nor will we know the answer to these questions until we have identified the killer or killers. But we seem unable to bear the burden of such rational uncertainty. Simultaneously with the announcement of the Tylenol murders, the media as well as the persons responsible for apprehending and convicting the culprit were informing the public that the killer was a "madman." On Oct. 2, after the sixth victim died but before the news of the seventh victim had reached the press, one news story spoke about the FBI's mounting a broad investigation to find a "crazed madman" responsible for the killings. Mind you, they are not looking for just a plain madman, they are looking for a "crazed madman"! The Oct. 11 Newsweek story on the case stated matter-of-factly: "The death of seven people who took the drug triggers a nationwide alert -- and a hunt for a madman." It must be nice to be so sure.

An editorial in The New York Times on Oct. 5, taking for granted that the Tylenol terrorist was mentally ill, intoned: "The acts of aberrant minds are hard to guard against, impossible to accept. Hurricanes are easier to cope with than psychopaths." This is simply not true. Worse, it is true only if and because we equate viciousness with mental illness and thus incapacitate ourselves both from understanding the deed and punishing the doer.

Let us recall in this connection that in his first news conference after being shot by John Hinckley Jr., President Reagan asserted, as if it were the most obvious thing in the world, that Hinckley was "sick." That hint was evidently not lost on the federal prosecutor who, in concert with the defense, managed to secure a psychiatric "acquittal" for the would-be assassin. Hinckley was not permitted to talk during his trial. But there has been no stopping his self-revelations since his "acquittal." In view of the letters Hinckley has sent to Newsweek and others, can anyone really doubt that, the sworn lies of the psychiatrists notwithstanding, Hinckley is not mad but bad? What else must he do to prove that he is not a sick patient but a sickening punk?

But the magic of madness is a powerful lure and is useful to boot. A variation of the Hinckley scenario is unfolding already. Instead of preparing to prosecute and convict the Tylenol terrorist, the highest ranking law enforcement authority of the State of Illinois is diagnosing him and thus laying the ground for his insanity defense. In an Oct. 2 news story, State Attorney General Tyrone C. Fahner is quoted as saying: "This was not the act of the McNeil people (the manufacturer), but the act of a crazed madman." But isn't it possible that the Tylenol killer is a terrorist who, instead of planting car bombs, is planting cyanide? Isn't it possible that he has (or they have) made certain demands on the government that we haven't been told about because our "betters" do not believe we could take such news? Such reflections are evidently considered to be foolish or irrelevant. No one seems to entertain them, at least not publicly.

Why, indeed, should we be uncertain, cau tious and punitive, when we can be certain, decisive and therapeutic. Never mind that madness cannot explain the events in question. There are millions of people in the world who are said to be mad. Do they poison people unknown to them with cyanide?

Finally, there remains the bitter fact that poisoning people who have harmed no one has been a favorite pastime of governments and government officials. How many people have been poisoned by our government with Agent Orange or with marijuana sprayed with paraquat? How many people were poisoned by government psychiatrists with cocktails laced with LSD and God-knows-what-else?

The Tylenol terrorist is not a clever killer, he is a "crazed madman." Credo quia absurdum.