An old article of William F. Buckley’s I found while looking for something else (a title for this website, as it happens): I am lapidary but not eristic when I use big words, published in The New York Times Book Review in 1986. He takes too long to make the point and never does actually help with the question of what unusual words a writer can use, but it may be of interest.
I would contest one claim. He’s speaking of the reader who runs into a word he doesn’t know.
That reader has the usual choices: he can ignore the word; attempt, from the context, to divine its meaning precisely or roughly . . . or he can look it up. Are these alternatives an imposition?
No, the reader has a fourth choice: he can stop reading. Readers may have changed since 1986, but I suspect they haven’t changed all that much. Now, a discouraging number of readers seem to look for signs saying “This isn’t for you” — even readers who have paid for the book or subscription and presumably want to invest their effort as well as their money. Even one unusual word or name they don’t recognize can put them off, and two or three or more will almost certainly send them to the next article or to the television.
Some readers will not be prevented from feeling this way, but you can prevent others from feeling put off by some care to define unusual words and names. For reasons I don’t understand, the slightest explanation can make such a reader feel all right, perhaps because the identification by itself signals that they are not alone in not recognizing the word or name.
A reference to “Anaximander” will put them off, but “the ancient Greek philosopher Anaximander” or “the pre-Socratic philosopher Anaximander” or “Anaximander, a Greek philosopher writing in the sixth century B.C.” will keep them reading. This identification doesn’t give them any real knowledge, and it may seem patronizing, but it does reassure them that the article is indeed for them.