The Simpsons / Insane Troll Logic

Season Two

Season Three

"Bart The Murderer": Fat Tony "explains" to Bart how hijacking a truckload of cigarettes isn't wrong.
Bart: Uh, say, are you guys crooks?
Fat Tony: Bart, is it wrong to steal a loaf of bread to feed your starving family?
Bart: No.
Fat Tony: Well, suppose you got a large starving family. Is it wrong to steal a truckload of bread to feed them?
Bart: Uh uh.
Fat Tony: And, what if your family don't like bread? They like... cigarettes?
Bart: I guess that's okay.
Fat Tony: Now, what if instead of giving them away, you sold them at a price that was practically giving them away. Would that be a crime, Bart?
Bart: Hell, no.
In "Homer at the Bat", Chief Wiggum arrests Steve Sax for every unsolved murder in New York solely on the basis that Steve Sax is a New Yorker.
"Dog of Death": Homer's "plan" for winning the lottery.
Homer: I've got so many [lottery] tickets I can't lose!^note
...
Homer (to Bart) If you were 17, we'd be rich! But noooo, you had to be 10!

Season Five

In "Cape Feare", Sideshow Bob is appealing for parole. At his hearing, he argues that the tattoo on his chest, which reads "DIE BART, DIE" is actually German for "The Bart, The". Everyone present buys this, with one person claiming that "No one who speaks German could be an evil man!" Thus, this vengeance-obsessed, twice-convicted, attempted murderer is allowed to go free with no objections.
"Bart Gets An Elephant": Homer considers selling Stampy the Elephant to an ivory dealer. He tells a worried Lisa that someone with lots of ivory is less likely to harm Stampy than one whose ivory supplies are low.

Season Six

A flashback scene in "Homer the Great" showed that when Homer was a kid, the other kids in the neighborhood named their club the "No Homers Club" just so he couldn't join. But they let Homer Glumglitch join, claiming that "no Homers" meant plural; they could have one. (Kids Are Cruel and bad at grammar, it seems.)
- And at the episode's conclusion, the Stonecutters form a new iteration of the same club because they didn't like Homer's reforms. Homer Glumglitch is once again a member.
"And Maggie Makes Three": Bart and Lisa are talking about what gender the new baby (Maggie) will turn out to be:
Lisa: I hope it's a girl.
Bart: You know nothing about genetics, Lis: it goes boy ^noteBart Simpson, girl ^noteLisa Simpson, boy ^notenew baby, girl.
"Bart's Comet": After the comet fails to hit Springfield and burns up in the polluted atmosphere, Moe blames the observatory for the cause of the approaching comet. "Let's go burn down the observatory so this'll never happen again."

Season Seven

"Bart on the Road":
Homer: Donut?
Lisa: No thanks. Don't you have any fruit?
Homer: This has purple stuff inside. Purple is a fruit.
In "Lard of the Dance" where Homer buys bacon to get its grease to sell:
Bart: You're spending more money on bacon than you're getting for the grease.
Homer: Yeah, but your mother pays for the bacon.
Bart: Doesn't she get her money from you?
Homer: And I get my money from grease. What's the problem?
"Lisa the Vegetarian": "If God wanted us to be vegetarians, He wouldn't have made animals out of meat!"
"Much Apu About Nothing": an isolated incident involving a bear wandering into Springfield is responded to by the creation of a multi-million dollar "Bear Patrol". When Homer states that the organization is stopping bears from coming into town, Lisa compares his logic to claiming that the ordinary rock she's holding is a potent tiger repellent, since there aren't any tigers around. Homer, naturally, offers to buy the rock.

Season Eleven

In "The Mansion Family" the family are hired to watch Mr. Burns' house whilst he's away; Burns' rationale for choosing Homer for the job:
Burns: Who's that fellow who always screws up and creates havoc?
Smithers: Homer Simpson, sir? [He indicates a CCTV screen which shows Homer enter his workstation and begin sawing through the console for no apparent reason]
Burns: Yes. The way I see it, he's due for a good performance!
In Guess Who's Coming To Criticize Dinner" Homer takes the kids to the Springfield Shopper, where a lady talks about it's founder, Johnny Newspaperseed, a young boy who roamed America founding newspaper. Homer asks her a question.
Homer: If he's so smart, how come he's dead?

Season Twelve

Season Thirteen

"Poppa's Got A Brand New Badge": "But, Lisa, if we start conserving, the environmentalists win!"

Season Sixteen

In "Alls Fair In Oven War", Marge makes dessert dogs ^note for her family. Bart's thoughts after trying it:
Bart: It's dessert, but it's hot dog so it's good for you!

Season Seventeen

"The Monkey Suit": creationists seeking to ban the teaching of evolution succeed by getting a scientist to testify in court that evolution is a myth — a scientist with a degree in "Truthology" from "Christian Tech". It's a shot at "doctors" like Kent Hovind and Carl Baugh. Both of which got their doctorate degrees the old fashioned way, by buying them.

Season Twenty-One

"O Brother Where Bart Thou?": During a snowstorm, Homer mocks Lisa's belief in global warming, and she says global warming can have this result. (This, by the way, is why 'climate change' is the preferred term now.)
Homer: I see. So you’re saying warming makes it colder. Well, aren’t you the queen of crazy land! Everything’s the opposite of everything!

Insane Troll Logic / The Simpsons