Blog post the Fifth. Have you ever said "I could care less" only to be corrected by the person you are talking to (or a bystander) that what you 'meant' to say was "I couldn't care less"? I know I have been corrected on this once or twice.
This is often given as one of those inexplicable linguistic phenomena where an expression morphs to a wording with literal opposite meaning while the intended meaning remains the same. I stumbled across this history of the evolution of the two phrases as an example of just such an expression. At first glance, it does seem that "I could care less" is 'wrong', and so the word mavens seem to be right. But are they?
Imagine yourself saying "I couldn't care less." Notice how precisely you must enunciate. Notice how careful and precise you are in your meaning: "I care as little about this as I possibly could." There is something about this choice of words that suggests effort, emotion, and mental calculation. It is as if instead of saying "I don't care", you are saying "I really really really don't care," but you are saying it in a very precise way. There is something about all that effort to express "I don't care" which is suggestive of one who doth protest too much. It is often used as a weapon or a defense mechanism about something you actually do care about, "I couldn't care less what you think!" (when in fact, I do). Note that that is not a case of sarcastically "meaning the opposite". Rather it is a case of defensive lying to protect your own feelings and/or hurt the feelings of the other person. Whether or not it is a defensive/hurtful lie, or actually means that you are at the rock bottom minimum of concern for the topic at hand, you mean what you say you mean.
Now imagine yourself saying "I could care less". Notice how the words slide lazily off the tongue. You toss off the words without really thinking. There is more emphasis on "care less" than on 'couldn't'. There is something about the casual laziness of this expression which suggests that you are not being particularly careful in your choice of words nor worried about your exact meaning. But if you actually think about what you mean, do you really mean "I could not possibly care less, because I care as little as humanly possible." I do not think that that is what I mean when I say "I could care less."
What do I,and I think most people, mean even if I never thought about my meaning consciously (until now)? The first thing that comes to mind is, "I care so little, that it is not worth the effort to care less." It ironically suggests that you are at the minimum of caring because it would take effort to care any less and you would have to care more in order to exert that effort. I think it also carries and element of threat: "keep pushing me, and I will care even less than I already do." You could even mean both at the same time: "keep pushing me and you will piss me off enough that I will exert the effort it takes to actually care less than I already do." You could also mean "I care so little, that I cannot be bothered to use the (supposedly) correct form of this expression."
So, next time someone corrects you on "I could care less". You have an answer: "no, what I really meant was, 'I could care less'."
Given the title of my blog, it is worth pointing out that whatever you might mean, this is one case where it is probably "Righter to be nicer."