Fallacy: Appeal to authority
Have you?
What do YOU know about it?
Nor does it make YOU one.
No it doesn’t.
You haven’t provided any “research of linguists” to support your position. I believe someone posted something from the “wiki dictionary” or some such nonsense. It was open-sourced, which means literally ANYONE can submit an etymology. You haven’t made your case at all, and the fact that you believe you have authority on your side is laughable.
Sorry to be blunt, but you’re just talking out of both sides of your mouth. I’m tempted to ask you exactly what the distinction is that you are making between “ironic” and “sarcastic”, but I’m really just tired of wasting my time with you. What you’re writing feels disingenuous to me, like you don’t really have a position and just want to take the position contrary to someone else for the sake of argument alone.
I sure hope this wasn’t directed at me, because I never said users of the phrase were morons. I believe someone ELSE, not me, referred to REPEATING something uttered by a moron. So first of all, repeating something uttered by a moron does not make you a moron. Second, there was obviously some hyperbole being employed there. I doubt he meant anyone was literally a moron. You are being FAR, FAR too literal here, which is odd for someone who champions a phrase that is anything but literal.
What are these “four mechanisms”? I am aware of several of you arguing that “could care less” is deliberately sarcastic. I find this line of reasoning dubious, and have explained why over and over again. So if you didn’t get it, you’ll just have to read the thread. I’m not aware of these alleged other 3 “mechanisms”. I’m guessing they’re not far off from the “sarcasm” angle, but please feel free to elaborate it that’s not true.
If you guys really want to play the appeal to authority on the internet game, fine. I’ll play along. Here ya’ go:
http://public.wsu.edu/~brians/errors/care.html
Paul Brians, Professor Emeritus of English:
I’m sorry you feel that way. I don’t know why you’re being so hostile, or why you feel that everyone is adopting a devil’s advocate type position for shits and giggles. I certainly don’t have a reputation here or anywhere as someone who enjoys argument for argument’s sake. I guarantee you I’m being completely sincere with my thoughts. I would appreciate it if you would stop casting aspersions on posters here and what their mindset is in regards to this topic.
As for irony vs sarcasm, the distinction I’m making is one of tone. The phrase “I could care less” is clearly ironic–the meaning is the opposite of the literal. But it’s not necessarily said with sarcasm. Sarcasm contains an element of mocking and contempt to it. Irony need not. If you don’t want to make the distinction, that’s fine with me. It doesn’t change my point at all that the GQ answer is that we really don’t know exactly what path this phrase took, and that there are four possible theories offered up by linguists and other language experts.
Have you actually read through this thread? Serious question, because this response and the response to Wendell (who mentions in this thread his linguistic credentials–he’s got a master’s in it) make it seem to me like you are the one who is arguing for the sake of argument alone. And there have been plenty of links in this thread to respected linguists discussing the possible paths for this phrase’s evolution. UPenn’s “Language Log” blog is a particularly interesting read in this regard.
But, in case you are being sincere and just missed it, it’s neatly numbered for you in post #193 in this thread. One of the other three mechanisms is the one you propose–simple repetition of an error.
I was referring to “I’m good”, and no, as a response to “how are you?” it is NOT semantically correct, for the reasons I’ve already indicated – it doesn’t mean what the speaker thinks it does. The difference between an adjective and an adverb in this context is significant. It’s like the difference between “I feel bad” (remorseful or unwell) and the regrettably all too common “I feel badly” (apparently incompetent at sexual groping). Consider the perfectly acceptable phrase “I feel hot”. Would you say “I feel hotly” anywhere outside the context of the degree of arousal caused by groping? I can’t wait for the linguistic freethinkers to inform me that either form is acceptable, because, well, because what the hell! 
Because it isn’t. Or at least, “colloquialism” fits the bill much better. “Couldn’t care less” certainly isn’t an idiom, it’s an expression. Its incorrect variant is an aberration of the expression, apparently regional, which is just what a colloquialism is. I’ve never seen “could care less” in any listings of common idioms; maybe you have. An idiom is most commonly an expression that draws a parallel with a figurative situation, like “letting the cat out of the bag”, “spilling the beans”, or “fit as a fiddle” and isn’t meant to be taken literally because one is supposed to understand the parallel. It’s true that it can also refer to stylistic usage, but “colloquialism” seems a much better fit for this particular thing.
Well, here you go. Also, here. I’ve never heard it not being considered an idiom. I mean, yes, it’s colloquial, but it’s also an idiom.
Just to be clear, you’re saying that in the phrase, “I’m well,” “well” is an adverb, right?
Nice try at a gotcha, and point taken as I was thinking ahead to the other examples I gave where the adjective and adverb forms convey entirely different meanings. In this case, both “good” and “well” are adjectives but they are adjectives with likewise entirely different meanings, which is why “good” is wrong. It implies a skill or moral quality, while “well” implies a state of health. It’s a parallel with the examples I gave, though not because it’s a different part of speech.
I suppose I should at least be grateful that no one has yet come along suggesting that “I feel badly” is perfectly correct! 
“I’m good” is fine. Even Grammar Girl (whom you cited before) agrees.
No. Both of your claims here are incorrect.
The meaning of “I could care less” is not the opposite of the literal meaning. *The literal meaning of “I could care less” is “I care some small amount.” *
The opposite of that literal is “I care some amount other than a small amount.”
How could such a statement (“I care some amount other than a small amount”) possibly be considered to be “clearly ironic”?
My quick reading of it is that Grammar Girl, as befits the name, appears to be justifying the usage on grammatical grounds. It is grammatically correct – I already said that. But unless you’re describing your golf or poker skills or your personal virtue, it’s not semantically correct, though obviously very common usage, and I’m sure I’ve said it myself conversationally. What I object to is the Economist writer – or GG – implying that it is unreservedly correct, because it is not.
I have to say as an aside that I love language as much as anyone here, and I love playing with its creative expressiveness. But familiarity with the historical challenges of trying to get a handle on the formalisms, particularly in the area of machine translation, has left me with little patience for some of its gratuitous stupidities. No one begrudges the fact that most common idioms require experiential context to understand – something that creates huge challenges for machine translation – but to that I say: tough! Suck it up! Idioms enrich our language, and natural language is for humans, so we get to control it.
But some level of formal consistency applies to human comprehension as well. Sometimes wrong is just wrong, and should be called out and corrected. When usage becomes so muddled that you can drop a negation and end up with exactly the same meaning, you wonder how the hell we ever communicate. And the answer is, sometimes we don’t. When Jimmy Carter went to Poland in 1977 his translator informed his hosts that he had left America forever, but it was all good because he had carnal desire for the Poles and wished to grasp their private parts. 
That’s not how I hear it/read it. The literal meaning of “I could care less” is “I couldn’t care less.” That seems to be one definition of the “opposite” of the literal meaning to me.
I don’t think I would disagree with you there. As I alluded to before, there are plenty of peeves I have when it comes to language. And I personally think there is a usefulness to the push-and-pull between the language connoisseurs and champions of common usage. At the very least, it lets us think about what we are saying more closely, even if popular usage ends up completely ignoring it in the end. My own writing is much more conservative when it comes to the formal sphere. I would never use “I could care less” in that context. That said, I also probably would never use “I couldn’t care less,” either, because, to me, those are both in the colloquial sphere when it comes to diction.
Sorry. I got that wrong. The meaning of “I could care less,” as an idiom, is “I couldn’t care less.” The literal is that you could care less. So when you are saying “I could care less” in the idiomatic sense, you mean you couldn’t care less. That, to me, falls under the broad brush of irony. You are literally saying that you actually could care a little less, but, really, you couldn’t.
Killing Time, I have a master’s degree in linguistics. I mentioned that earlier in the thread. You haven’t studied linguistics, right? Take some courses in it and come back when you have some knowledge of the field.
It’s not considered an idiom, if you accept the definition of “idiom” found in sources such as these:
Oxford:
Merriam-Webster:
“I couldn’t care less” has a very literal meaning (‘I care not at all, less than which there is nothing.’) It’s not the case that the expression “cannot be understood from the meaning of its separate words” (as M-W has it). It’s not an idiomatic expression at all.
The same is true of “I could care less.” It has a literal meaning (though neither that meaning nor its opposite is what users intend to convey when they speak or write the phrase).
Both phrases or either may appear in “lists of idioms,” but that’s not the same thing as their actually being idioms.
I would say that the meaning of “I could care less” is not deducible from its individual words. Ergo, an “idiom.” If you want to classify it as a “colloquialism,” or an “American saying,” or whatever, please substitute those words. I just haven’t heard any argument before about it being considered an idiomatic use of language.
I quoted a bit more of my original post than you did to show how obvious it was that I was not equating “standard” with “accepted in formal writing.” The transformation of my clear request into a supposed request for “formal writing” examples is, perhaps, one of the more blatant appearances of a straw man argument in this thread.
It should be clear to those reading in good faith that I was asking for examples of respected users of English who used the phrase “could care less” to describe their own reactions or the reactions of others, in any setting in which the words of those users might be recorded. Your Liberman citation is not helpful in this regard, as he is clearly merely discussing the usage.
A statement by Liberman that the phrase is perfectly fine for people to use and that he uses it himself is in no respect the same thing as an actual example of him using it himself.
And that is all we have, so far: respected users and experts in English saying it’s fine to use the phrase. What we do not have, so far (save for Bill Clinton) is examples of people like Liberman or Pinker actually using the phrase to express their own state of mind or the state of mind of another.
I hope that you will keep trying to find such a citation (for Liberman, Pinker, Zwicky, or for that matter any recent winner of a National Book Award, Man Booker Prize, Pulitzer, or any other well-recognized award). Such people are often interviewed; an interview would be an ideal venue for observing language usage in action. Other potential sources: lectures (whether video or text transcriptions); memoirs of any sort (article, book, etc.); published letters; essays.
Again, we are not looking for examples of people like Pinker discussing the usage of “could care less,” or saying that the usage is acceptable, or claiming to use the phrase. We are looking for examples of people like Pinker actually using the phrase to express their own thoughts.
I wish you luck; frankly I’d like to be able to place at least a small wager on the outcome.