This blog was linked to a while ago in a Reddit discussion of uninterested and disinterested. (My opinion on them is that uninterested is restricted to the “unconcerned” meaning, while disinterested can mean either “unconcerned” or “impartial”, and that’s an opinion based on both historical and modern usage. In fact, despite the dire cries that people are causing the two words to smear together, it actually looks like the distinction between them is growing over time.)
The reason I bring this up again is that one of the Redditors was proposing that having a strong distinction could make sense, because:
“Some people draw a distinction between disinterested and uninterested. There is nothing to lose and perhaps subtlety to be gained by using that distinction yourself. Therefore observing the distinction should always be recommended.”
But I’ve already asked my question about this in the title: is there really nothing to lose? Is there no cost to maintaining a strict distinction between words? Or, more generally, is there no cost to maintaining a grammar rule?
Well, in a myopic sense, no, there’s nothing much to lose by having the rule. In the case of uninterested and disinterested, it would be hard to argue that not being able to use disinterested to mean “unconcerned” is a substantial loss. It can be done, though: I, for instance, am a great lover of alliteration, and as a result, I like to have synonyms with as many different initial letters as possible. There’s a cost, small though it may be, to not having disinterested available as I’m constructing sentences. But that’s a triviality.
A more substantial consequence is that it introduces a discontinuity in the historical record. If we decide that from now on disinterested only means “impartial”, then historical and current uses of the “unconcerned” sense will be opaque to people taught the hard-and-fast rule. That’s problematic because, despite the belief of some people that this is an illiterate usage, it’s actually common even for good writers to use. This, again, isn’t a big problem; we regularly understand misused words, especially ones whose intended meanings are very close to their actual meanings. Saying that we can’t have a rule of grammar because sometimes it isn’t followed is the sort of whateverism that people accuse descriptivists of, not a reasonable concern.*
No, the true cost is a higher-level cost: the overhead of having another distinction. This might also seem trivial. After all, we have tons and tons of usage rules and distinctions, and a lexical distinction like this is really little more than remembering a definition. But let me illustrate my point with an example I recently saw on Tumblr (sorry for the illegibility):
The distinction here is well-established: affect is almost always the verb, effect almost always the noun.** Yet here we see that it is costly to maintain the distinction. First, it’s costly to remember which homophone goes in which role. Second, it’s costly to make an error, as people may mock you for it. Third, it’s very easy to get it wrong, as the replier did here.
If there were really no downside to adding an additional rule, we’d expect to see every possibly useful distinction be made. We’d expect, for instance, to have a clear singular/plural second-person distinction in English (instead of just you). I’d expect to see an inclusive/exclusive first-person plural distinction as well, as I sometimes want to establish whether I’m saying we to include the person I’m speaking to or not. The subjunctive wouldn’t be disappearing, nor would whom.
But all distinctions are not made. In fact, relatively few of the possible distinctions we could make at the word level are made. And that suggests that even if the reasons I’ve listed for not maintaining a lot of distinctions aren’t valid, there must be something that keeps us from making all the distinctions we could make.
So next time someone says “there oughta be a rule”, think about why there isn’t. Rules aren’t free, and only the ones whose benefits outweigh their costs are going to be created and maintained. The costs and benefits change over time, and that’s part of why languages are forever changing.
*: Of course, if the distinction is regularly violated, then it’s hardly whateverist to say that it doesn’t exist.
**: Affect is a noun in psychology, effect a verb meaning “to cause” that is largely reviled by prescriptivists.