A commenter writes:
Well it could be worse. I hazard that in 50 years the sex sensitivities of the colloquial speaker will have caused the formal replacement of the generic singular pronoun (he) with the plural pronoun (they), which is safely without gender. Already constructions like these are ubiquitous among high-school age writers, and sanctioned by their teachers:
Everyone must choose their own path.
Each student selects their thesis topic.
Note in the second example the jarring (I hope!) juxtaposition of the singular verb with the plural pronoun. This is the future.
Buddy, you don’t know the half of it! Not only are high-school age writers being taught this by teachers, they are even taught this by some other writers (who must obviously be misguided hacks, given how badly they’re abusing the English language). Some examples from some of these awful people — to avoid unduly embarrassing them, we’ll call them William S., Jane A., W.H. A., Jonathan S., William Makepeace T.,
And every one to rest themselves betake
I would have everybody marry if they can do it properly
… it is too hideous for anyone in their senses to buy
Who makes you their confidant?
… every fool can do as they’re bid
A person can’t help their birth
There’s not a man I meet but doth salute me
As if I were their well-acquainted friend
(All sources are from the Merriam-Webster’s Dictionary of English Usage, where the full names of these miscreants are revealed.) [UPDATE: A more comprehensive survey of Jane A.’s works is in the Spurious Grammatic “Rules” of Every Sort Are My Abhorrence post.]
So, commenters, is it that all these writers (whose work ranges from the late 1500s to the 1900s) and many more were wrong, and you’re right, when you say that “their” can’t be used in these contexts? Is it that you have the Logic of the Language on your side — the same logic that tolerates the singular “you are,” “aren’t I?,” “ice cream,” and much more, but that as a matter of the laws of logic balks at a singular “they”? Or is it just that you’re discussing what you find aesthetically pleasing (or even pedagogically optimal, for instance with an eye towards teaching students usage that will satisfy self-described “purists” and will thus serve them well socially)? If it’s the latter, I’ll happily end the debate. But my sense is that many people who denounce the singular “they” (including where the singular relates to nouns with a collective meaning, such as “everyone”) and similar matters are making an assertion about correctness, and not just about their own tastes or about the most useful teaching approaches.