On this date in 1755, Samuel Johnson published A Dictionary of the English Language, which includes in his Preface this salutary reminder:
"Those who have been persuaded to think well of my design will require that it should fix our language and put a stop to those alterations which time and chance have hitherto been suffered to make in it without opposition. With this consequence I will confess that I flattered myself for a while; but now begin to fear that I have indulged in expectation which neither reason nor experience can justify. When we see men grow old and die at a certain time one after another, from century to century, we laugh at the elixir that promises to prolong life to a thousand years; and with equal justice may the lexicographer be derided, who being able to produce no example of a nation that has preserved their words and phrases from mutability, shall imagine that his dictionary can embalm his language and secure it from corruption and decay, that it is in his power to change sublunary nature, and clear the world at once from folly, vanity, and affectation."
By coincidence, I happened today on a post by Patricia T. O'Connor and Stewart Kellerman at Grammarphobia on comprise, in which they point out that the traditional sense of "contain," "include" from the eighteenth century has been gradually overtaken by the nineteenth-century is comprised of, to the point that the dictionaries list both usages as standard.
Their conclusion: "It's time to admit that the meaning of 'comprise' has changed. Pat's grammar guide Woe Is I includes the traditional view, but she has added the new usage to the notes she's collecting for a new fourth edition."
I have been teaching the traditional sense at Loyola for twenty years, and come September, my students will be advised that though some sticklers continue to object to is comprised of, there is no point in being fussy about it.
Some people, and many copy editors are among their number, crave certainties. They want English, in the form that they learned in school, to be preserved from mutability. They want to call a halt to those alterations which time and chance have hitherto been suffered to make without opposition. They are doomed to frustration.
The problem for teachers and editors is how to deal with conflicting advice on usage.* My former Enquirer colleague Jan Leach, responding to my post on copy editing fetishes, posed this question on Facebook: "How will we get everyone who teaches writing and editing to agree?" Well, we won't. And we will have to tell our students and colleagues that some matters are unsettled, that certainties about usage are frequently illusory, that they will have to learn how to make judgments, and that they will frequently be called upon to reconsider those judgments.
Incidentally, did you pass over without registering the singular they in the passage from Johnson's Preface?
*The simplest solution: Follow mine.