Kathy Schenck is writing at Words to the Wise about the clash over enormity.
Purists insist that the word should be understood in the narrow sense of “a great evil.” Hitler, Stalin, Mao, Pol Pot and others were guilty of enormities, and to use the word in any other sense, they say, trivializes it.
But more casual users have been using enomity for a long time in the sense of “of great size” or “of large dimensions.” It is in this sense that Barack Obama used the word in a sentence Ms. Schenck quotes: "I do not underestimate the enormity of the task that lies ahead."
I use the word in its strict sense; it’s a useful word to have in stock. I teach my students that there is a distinction here that fastidious writers observe. But I can’t ignore that the other sense appears to have become prevalent and that no one misunderstands it. No one imagines that Mr. Obama meant that he intended to embark on a task of great wickedness. (Oh, all right, sure there are, but I don’t read those blogs or listen to those radio shows.) I can think it regrettable that the two usages coexist and that the one appears to be crowding out the other; but when the speaker’s or writer’s meaning is always clear in context, it seems pointless to carry on about it. It may not even be justifiable to call it an error, and it’s certainly not an enormity.
Buckeye Sam posted a comment on the Words to the Wise entry: “Anyway, regarding "enormity," it's my one-word usage test.”
There, in a single sentence, you can see encapsulated what people dislike about purists and the mavenry. Someone is listening to you, not paying attention to the substance of what you say, but waiting for you to make a mistake. And it might not even be a mistake; it could be some aribitrary and idiosyncratic “rule” of which you are unaware, and about which there is dispute among the professionals. The purist is impatiently waiting to give a thumbs-up-thumbs-down judgment, and he is a hanging judge in a court from which there is no appeal.
Precision in the use of language is important. So is a sense of proportion.