One of the keener disappointments for writing teachers is the impoverished vocabulary that even the best students bring to their work. Diction, for them, isn’t worth the labor. They don’t recognize the arts of eloquence, oratory, forensics, and conversation, and if they did, and practiced them out of class, they might lose their friends.

“Try an experiment,” I sometimes urge students. “The next time you’re in the cafeteria with four friends and the colloquy turns to Obama, mutter this: ‘Such mellifluous sonorities the man produces.’ See how they react.”

The outcome shows that little in the leisure time of adolescents contributes to a better verbal arsenal. In the early ages, the vast majority of vocabulary building takes place in informal settings, not in classrooms. By college years, though, the settings surrounding most freshmen damage their diction more than enhance it, and course readings and class discussions often mark their only exposure to finer expressions. Their writing assignments are often the only chance to implement them.

It is strange, then, that so many teachers and writers discourage young people from picking up a thesaurus when they write. Countless times when I have pressed students to find a better word, a Latinate one, they have scrunched up their eyes in uncertainty, and when I have pushed a thesaurus at them they’ve replied, “But my former teacher told me not to use it.”

“Why?” I ask.

“Because I might get it wrong.”

Simon Winchester, journalist and author of The Professor and the Madman, made the point forcefully in The Atlantic in 2001. In “Word Imperfect,” he wrote, “Roget’s Thesaurus no longer merits the unvarnished adoration it has over the years almost invariably received. It should be roundly condemned as a crucial part of the engine work that has transported us to our current state of linguistic and intellectual mediocrity.” Roget’s prime error was to omit definitions in lists of synonyms. Without definitions to accompany each word, Winchester argued, Roget, “wrongheadedly and irresponsibly…produced no more than an unexplained and inexplicable list of quick fixes.” As a result, “the word chosen with each presto! is often wrong. Sometimes very wrong. Often slightly wrong. And at the very least, frequently, curiously, and discordantly off. For example, a freshman student of mine, who admitted to using Roget, attempted to improve the phrase ‘his earthly fingers’ by changing it to ‘his chthonic digits.‘”

For Winchester, that epithet was a disaster. For me, though, it’s a chance for the student-writer to learn. Of course students make mistakes. That’s how language use improves in adult life — trial and error. No trial means no error, and no growth. Winchester and other anti-thesaurus teachers concentrate writing instruction on the final product in class assignments. They should regard writing instruction in developmental terms, and see errors in usage as healthy vocabulary struggles. That’s why I often require students to compose two versions of one paper, one in low diction and slang, the other in multi-syllabic, Latinate, thesaurus words. And to use their thesaurus avidly. (See here for a recent bio on Roget.)

In Winchester’s example, the important thing isn’t that the student came up with an absurd term. The important thing is, in fact, missing: how Winchester turned that absurdity into verbal knowledge.