Dirty Harry, the movie cop, wasn't wrong very often. A bit nasty and heavy-handed with criminals. But in the end, he was usually right.
But in one of my favorite Dirty Harry scenes, he couldn't have been more wrong.
It was early in "Sudden Impact." He had just looked at a murder victim. He walked away and appeared to be brooding.
A fellow cop, munching a hot dog, asked him if crime was starting to get to him.
Dirty Harry said: "No, this stuff isn't getting to me. The shootings, the knifings, the beatings, old ladies being bashed in the head for their Social Security checks, teachers being thrown out of a fourth-floor window because they don't give A's. That doesn't bother me a bit.
"Or this job, either -- having to wade through the scum of this city, getting swept away by bigger and bigger waves of corruption, apathy, red tape. Nah, that doesn't bother me.
"But you know what does bother me? Do you know what really makes me sick to my stomach? Watching you stuff your face with those hot dogs.
"Nobody -- I mean nobody -- puts ketchup on a hot dog!"
There was a time when Harry would have been right. Back when Joe the Greek had a steam-leaking hot dog pushcart in my neighborhood, you couldn't have ketchup because he didn't have any. He didn't have any because nobody would have dreamed of asking for it.
And if somebody did ask for it, the word would have spread through the neighborhood and that person would have been viewed as some sort of weirdo.
But as most other civilized standards decline in our society, so goes the preparation of a proper hot dog.
A random survey of some of Chicago's traditional hot dog outlets shows a depressing, if not alarming, rise in the misuse of ketchup and the abuse of the classic Chicago hot dog.
Maurie Berman owns Superdawg, where I've been eating classic hot dogs for about 40 years.
Since 1948, he has made millions of hot dogs the way nature intended: your choice of yellow mustard, relish, onions, tomato, peppers and -- the subtle secret of a great Chicago dog -- a dash of celery salt.
"But now," he says, "I see more and more desecrations of the Chicago hot dog. Yes, we provide ketchup, but we have the customer defile it himself.
"We say, 'Sir, the ketchup bottle is on the side. We'll ask you to squirt that yourself.'
"See, today, kids love ketchup. They slather it on their fries and on the dogs. They're somehow indoctrinated. Maybe the mustard is too sharp for them. They are unaware of the traditions. I guess it's just evolution.
"Worse than ketchup is this cheese dog. Sacrilege. I used to turn down requests for cheese dogs, but now I have to succumb. But no chili dogs. Ain't gonna do it. Never. No way."
John Miyares, who serves hot dogs at Irvings near the Loyola college campus, says: "No ketchup, no kraut. That's the law. But when you're younger and your mom lets you put ketchup on the hot dog, you get used to it, I guess. The people about 35 and over, they get upset if you mention ketchup, especially if they're born and raised here.
"But we get a lot of students from out of town, and they all want ketchup. Except if they're from New York. They want steamed sauerkraut."
At Fluky's, the counterman said: "It's happening more and more. The teen-agers, the high schoolers, come in for lunch, and most of them want ketchup. I guess they get used to it because of all the stuff McDonald's puts on its burgers. Older people hear ketchup and they make a face like they are feeling sick."
At Demon Dogs, manager Pat Carso said: "You have to ask for it. And more people are asking. I don't know why. Maybe parents think it is better for their kids. But we choose not to put it on. Even if they say 'everything.' In here, that does not include ketchup. We don't even keep it up front. We have a little bottle in the back if people ask for it."
Like so many other problems with modern young people, this can be traced to parents who are indifferent, neglectful or lacking standards of their own.
If a child requests ketchup on a hot dog, a parent should be firm and say: "You can put ketchup on a hamburger or on your fries. But know that it is forbidden to put it on a hot dog."
The child will probably moan, yowl and ask why he can't have ketchup.
So a good parent will say something like: "Because if you eat a hot dog with ketchup, do you know what will happen? Tonight, when you sleep, a giant, slimy lizard will crawl through the window and gobble you all up and all your toys and our doggie, too. That's what happens to children who put ketchup on hot dogs."
Well, after a few screaming nightmares about being chomped by slimy green lizards, the tyke will forget about ketchup and develop a taste for yellow mustard. Just ask any reputable child psychologist. No, don't ask them. They probably let their kids have ketchup.