Britain has great theater. America has to make do with New York, but the town, like Old Vic, almost never lets you down. Its latest saga is about the man who shot four teen-agers on the subway: Is he a hero or a bum? The mayor and police chief say the latter. The people yell otherwise. The people, as usual, are wrong and the mayor, for a change, is right.

It is only the facts that are in dispute, since it is not exactly clear what happened on that subway train. At first it was reported that the man went from car to car, looking for the four teen-agers who had earlier held him up. Later, it turned out that he had not gone looking for the teenagers, but they for him. They approached, asking first for a match and then for $5 -- a ritual of escalating extortion well known to most New Yorkers. In the manner of Charles Bronson in the movie "Death Wish," the man said, "Yes, I have $5 for each of you" -- and shot them one by one, none of them fatally, but two of them critically. One may be paralyzed for life.

As can be expected, New York has had a field day with this event. Talk- show radio hosts, who collectively represent a rebuke to the very idea of the First Amendment, have stirred the caldron of controversy: Did the guy do right? Did the guy do wrong? New Yorkers said he did right, and they even called the police department hot line to tell the cops to lay off their new-found hero. More people should do the same, they said -- rat-a-tat-tat, you dirty rat.

This is not a terribly surprising reaction since 1) people who call radio talk shows are a bit hysterical anyway, and 2) something has to be done about crime on the subways. The fact that the kids were black and their shooter-upper white should, at the very least, be kept in mind. If a guess is permitted, lots of people thought that if the four were not guilty of much in this case, they either had done something worse in the past or would do it in the future.

There's a sinister and ugly logic at work here. It seems indisputable that if more and more people shot punks who harass and rob people in the subways there would be less and less harassment and robbery. If the chances of getting your kneecap blown off were raised to about 50/50 for subway robbery, there would be a lot less of it.

But what, really, is the issue here? The answer, alas, is not the one being discussed -- not whether New York's new hero is a deserving one. It's obvious that society can't permit people to carry guns and casually shoot people who they think are threatening them. After all, one kid may be paralyzed for life. Suppose he was actually going to rob that fellow of $5. Does the punishment here fit the crime? Why didn't this so-called vigilante just pull his gun and tell the kids to back off? They didn't draw a weapon on him. And later it turned out they were armed only with screwdrivers -- weapons, certainly, but not exactly submachine guns. Why did he have to shoot them all?

The answer, I fear, is just that -- fear. The so-called vigilante is a metaphor for urban America. He's afraid. There's nothing cool and composed about him. He's either pathological in his own way, or crazed by fear and racism -- the two, as usual, going hand in hand. He shoots because he's scared, and afterward the people cheer him on because they're scared too. Only no one wants to admit that.

Instead, people compare the shooter to the Bronson character in a movie, inventing him for their own purposes. Insanity becomes sanity and lawlessness becomes legality because when it's the other way around, it doesn't work either. Is it sane for the innocent to always be the patsy? And what kind of legality is it when punks roam the subway at will, knowing either that there are no police or, if there are, they can't do much? They cannot hit them or beat them or, much of the time, even jail them.

So once again, New York supplies the theater -- a morality play about contemporary urban life. Is the man who shot four kids mostly in cold blood and just a little bit in self-defense to be condemned or praised? The answer is both simple and complex. Condemn him, because two wrongs still don't make a right. And study him real close.

All it takes is a mirror.