[Note: I may not entirely endorse this line of thought, retrospectively. Tread carefully.]
For some reason I don’t really understand many of us hate it when people make mistakes with language. It’s one of those things where the level of vitriol levied seems greatly out of proportion to the harm inflicted. I’ve yet to hear of any theory as to why this is.
Things get even more complicated when considering that people react this way to different mistakes. Some are driven up the wall by “irregardless”, while someone else’s pet peeve is the substitution of “defiantly” for “definitely”. It grinds my gears when people say “capitol” when they mean “capital” or “principal” when they mean “principle”. I want to jail people who are sloppy enough to get fooled by false friends.
Other things don’t bother me. When I argued in defense of “literally” used figuratively I also defended a several other “bad habits”. So what’s the difference? Well, some things are just mistakes while other things have a hidden logic to them.
The much hated “I could care less” belongs in the second category. Yes it does.
I’m not alone in defending its use but I haven’t seen the exact same argument elsewhere, so here goes: The phrase is a mutation of “I couldn’t care less”, used to express how, well, how you care so little about something that it would be impossible to care any less. Your caring is infinitesimal; you have an epsilon of regard; the issue is of Planck-importance.
Changing it “I could care less” turns the phrase into its opposite, as removing a negation tends to do. Yet people use it to mean the same thing! This must be wrong.
It’s not. In the post about “literally” I said that people don’t say nonsensical things. There are exceptions (like “tenants” and “tenets”) but these are just cases of confusing one word for another. This isn’t like that. I guarantee you that no one says “could care less” because they are confused about the difference between “could” and “couldn’t”. If it didn’t make sense somehow, people wouldn’t say it.
Let’s look at “I could care less”. If we forget the original opposite phrase for a minute and just inspect it on its own terms, it seems to mean that you care about something to a certain extent but you’re open to the possibility of caring less. The degree to which you care isn’t set in stone. You can change how much you care, choose to let the issue go. Perhaps you’re just talking about it because it’s fun or interesting and not because its vitally important to you. If it was, you wouldn’t be able to just divest.
I’m not saying people consciously mean this, but the expression makes sense when interpreted this way and that probably contributes its use. A clunky and strange phrase like that wouldn’t come about by itself, but as an offshoot of “I couldn’t care less” it can exist.
“I could care less” feels like it means “this is ignoreable to me (even if I’m not strictly ignoring it now)”. It is not a degenerate, broken form of “I couldn’t care less” (and they are not interchangeable) but a different expression altogether that separated from the original by a process of linguistic speciation. While “I couldn’t care less” is a snarky way of communicating your utter disdain for an issue, “I could care less” is a straightforward way of expressing that any engagement with it isn’t serious.
Maybe. This explanation is probably more correct, but I still like mine and do think it has a little bit of validity, however partial. It does depend on whether my impression that “I could care less” is interpreted differently than “I couldn’t care less”—softer, less sarcastic, with a less intense rejection. I do only have my own subjective experience to go on, though.