Occasionally a critic will write something that gets readers seriously riled. God knows I’ve done it. If I had to list my three greatest hits of outrage, they would probably be my pans of “Pretty Woman,” “O Brother, Where Art Thou?” and “Let the Right One In.” It’s no accident that the last of those is a horror film. Over the years, I’ve ticked off more horror fans than I can count, and it’s all because of something that we totally share: a passion for the genre that’s nothing short of consuming. A great horror movie hits you on every level — heart, mind, eye, squirm-in-your-seat body shudder. Maybe that’s why when we disagree about them, it can feel like war.

Last month, in my review of “Halloween Kills” (which was premiering at the Venice Film Festival), I wrote something that ticked off a whole lot of readers, though in this case the offense wasn’t my decidedly negative review of the film. It was one sentence, tucked inside a parentheses. Looking back over the history of the slasher film, a subject I’ve been writing about for nearly as long as it’s been around, I described the original 1978 “Halloween” as “a mayhem-by-the-numbers knockoff of ‘The Texas Chain Saw Massacre,'” adding, “but let’s leave that topic for another time.” That was meant to be a shorthand quip. I never intended to leave the topic for another time. What I meant is that I had no active desire to explore it, since I’ve already explored it so often. I felt it didn’t need to be belabored again.

But oh, what a trigger that sentence turned out to be! The response on Twitter was fast and brutal. Here are some tweets that sum up the reaction:

“Halloween is a knock-off of The Texas Chain Saw Massacre on what planet? They couldn’t be any more different in style, tone, story, social commentary, etc.”

“I think we can all dismiss Owen Gleiberman’s Halloween Kills review as he thinks the original Halloween stole directly from The Texas Chain Saw Massacre. This following behind a long, sad chain of critics who have no respect for the horror genre.”

“Hey Variety, if you ever want someone who’s actually seen Halloween ’78 and The Texas Chainsaw Massacre enough times to know they’re really NOTHING alike, hit me up.”

“Wait. How is the original Halloween a knockoff of TCM?! Had you said Black Christmas, I would’ve been like I can accept that. But TCM?!!!”

“Totally excremental review by someone who doesn’t know excrement about the subject matter.”

“What do you expect from a by-the-numbers hack like Gleiberman?”

“Owen PLEASE explain the Texas Chainsaw Massacre parallel.”

Okay, I will. But first a bit of background. I became a horror fanatic in the ’70s, because I happened to grow up then, but also because that decade was a high-water mark for horror, one that spawned so many of the tropes that rule horror cinema to this day. Just think of all the classics that came out during that era. “The Exorcist.” “Alien.” “Carrie” (one of the two films that made me want to be a film critic). “The Wicker Man.” “Dawn of the Dead.” “Don’t Look Now.” “The Tenant.” “The Omen.” “The Last House on the Left” and “The Hills Have Eyes.” And, yes, “The Texas Chain Saw Massacre” and “Halloween.” The ’70s was the formative age of contemporary horror, a time when horror films across the spectrum were listening to and talking to each other. To be a horror fan back then was to drink from a cornucopia of movies that seemed, in their extreme way, to capture what was going on in the world as much as any movies you could name.

The first time I saw “The Texas Chain Saw Massacre,” it knocked me sideways. It wasn’t a documentary, but it almost felt like one; it seemed to weave the terror of real experience into its grungy vision of hell on earth. I went back to see it again and it was just as scary. Once, in the early ’80s, I saw it stoned, and it was scarier than ever. I’ve seen “Chain Saw” about 20 times, more than I’ve seen any other horror movie except for “Psycho.” It’s no accident that those two films loom so large. They‘re the twin poles of modern horror, and they’re intimately connected. “Psycho,” which I consider to be one of the 10 greatest films ever made, is the demon seed that spawned the slasher genre — but apart from its pure fear factor, it’s really a movie about the death of God. At the end of the shower scene, we feel hope and faith are swirling down that drain right along with Marion Crane’s blood.

“The Texas Chain Saw Massacre” echoed the shock and terror of “Psycho,” but in a wild-ass rural-devil counterculture way. It’s very much a post-’60s movie. “Psycho’s” Marion Crane, with her furtively erotic and sly-eyed scheme of stealing $40,000 so she can get married, is now, in effect, a group of roving kids in a van who act out the license of the sexual revolution, and there’s a Mansonite madness to the whole thing. “Chain Saw,” like “Psycho,” was based on the case of Ed Gein, the Wisconsin serial killer of the 1950s, and both films unfold in an existential trap-door world where a lunatic with a bad weapon can slice the life out from under you.

I didn’t see “Chain Saw” during its original 1974 drive-in run. But I saw “Halloween” the day it opened, on Oct. 25, 1978, and my feeling about it, which has never changed (I’ve seen it about six times), is that it’s a clever and diabolically well-executed movie that scares you without really haunting you. There’s no doubt that this trio of films — “Psycho,” “Chain Saw” and “Halloween” — might be considered the father, the son and the unholy ghost of the slasher genre. All three present us with scenarios that are in-your-face and over-the-top. But Norman Bates, in “Psycho,” and Leatherface, in “Chain Saw,” are two of the scariest human monsters the cinema has ever given us. And the reason they’re scary is that both characters feel real. The queasy pull of the reality factor, as hard as it can be to define, is there in the greatness of Anthony Perkins’ performance as Norman, and in the extraordinarily resonant too-freakish-for-fiction gruesomeness of the image of Leatherface: a wordless mouthbreather wearing a mask of dead skin, wielding a power tool like the maniac he is.

Is Michael Myers, in “Halloween,” a scary character? Of course. There are two or three points in the movie that always make me jump. But Michael is an extremely stylized scary character. Tall and ramrod-straight, standing there in his slate-gray jumpsuit, always photographed in a teasing peek-a-boo way, he’s an implacable force of evil who, from the famous opening sequence (Look! He’s a towheaded six-year-old who slashes his own sister! Like a suburban-tyke Norman Bates!), never seems like an actual person. He’s a hulking conceit: the slasher who keeps coming at you, like an android in a video game. The slasher who never dies. (The last shot of “Halloween” marked the true birth of franchise culture. That shot said, “We can do whatever the heck we want. Our desire to set up a sequel is more powerful than the rules you thought we were playing by.”)

Okay, I can hear you saying: How does any of that make “Halloween” a knockoff of “The Texas Chain Saw Massacre”? The two films, in a way that could hardly be more obvious, are quite different. “Chain Saw” is a demented backwoods poem of fear. “Halloween,” set in Haddonfield, Ill., a placid suburb that looks, during the day, like a Spielberg vista with more trees (maybe that’s because the film was shot in California), is a booby-trapped fright film built around a chatty group of high-school babysitters. It frightens you, but it has no real dread. It formalizes and roller-coaster-izes the slasher template of “Black Christmas” (1974) and, before that, “A Bay of Blood,” the 1971 Mario Bava film that invented the genre in an amusingly accidental way: The killings — knife through the face, two teenagers pierced by one spear — were certainly influential, but the “aesthetic” of “A Bay of Blood” arose out of the way that Bava’s staging of the story was so logy and inept that there was no weight to it. The film almost inadvertently created the rhythm of murder!/ho-hum story filler/murder!/ho-hum story filler/murder!

“Halloween” mirrors that formula. But what it really mirrors — and, yes, what it rips off — is the primal image of a slasher in a mask. For that, of course, was the defining image of “Chain Saw’s” genius. Its director, the late Tobe Hooper, was likely influenced by photographs of the British serial rapist Edward Paisnel, who terrorized the Channel Island of Jersey in the ’60s and became known as the Beast of Jersey; he wore a grotesque rubber mask that very much resembles Leatherface’s mask. And, of course, the creepiness of “Chain Saw” also lies in the fact that Leatherface never takes that mask off. The mask is part of him. It expresses his identity, and his identity is that he has no identity. That’s the horror: that the force that kills you is faceless, and is therefore, when we imagine him, a projection of our own darkness.

“Halloween” ripped all of that off. But maybe one reason a lot of people wouldn’t see it that way is that “Halloween” so reduced the mystique of “The Texas Chain Saw Massacre.” Michael Myers, like Leatherface, is a hulking, overgrown arrested child (I like when he cocks his head back and forth like a kid while looking at the corpse he’s just pinned to the wall with his blade). Yet the mask he wears makes him less a walking nightmare than a shopping-mall specter. You know how at a Halloween party store, you always see those masks of Michael Myers and Jason (and, yes, Leatherface), and it’s always kind of funny that this is now a costume for 9-year-olds? In “Halloween,” Michael Myers’ mask already was that costume. It was the imitation, the catchy but harmless version, the stoic gray-white visage that anyone could buy, the one that made slasher movies right at home in the multiplex. It was the mask that scared you without necessarily getting under your skin, because in this case there was nothing underneath it.