The death of an exclamation.

William Blake had me thinking about death.

I was lying on my couch, Norton Anthology in my lap, when I stumbled on Blake’s poem “The Sick Rose.” I’d read the poem before, and I remembered its famous opening lament: “O Rose, thou art sick!”

What follows is a compact poem built of stark imagery. An invisible, amorous worm is flying through a storm at night. It descends on a rose. A death is at hand. And the perpetrator of the rose’s death, Blake warns, is none other than the worm’s secret love.

I reread the poem, parsing its lines for meaning. Then I read it once again. The night was late, and I felt drowsy. As sleep approached, an inchoate thought began to surface.

I sat up. O Rose, I thought. O Muse. O death.

I stood from the couch and found a pen. I tore off a piece of scratch paper, and on it I wrote myself a note: “What killed O?”

All living things must die, and the words of English are no exception. Groovy is no longer with us. Nor is its crisp-sounding relative, fresh—at least in the word’s midnineties usage.

English verse follows the same immutable law. Verse dramas had their own kind of literary life. They had a distinct spirit. At some point, that spirit began to decay, irrevocably so.

Of course, poetry itself didn’t die, just as English as a whole withstood the loss of groovy. Decay seems always to beget renewal.

Still, as I thought about Blake’s poem, I continued to wonder about O. It seemed to have a unique emotional color—a yearning, and a kind of rapturous crying out, that’s absent in today’s oh. And it used to be widespread. You can find O in Shakespeare and in Whitman, in the King James Bible and in Keats, in George Chapman’s 1614 translation of Homer’s Odyssey …

How did Ofunction? The more I asked myself the question, the less I seemed to know. So I consulted the language authorities. The Oxford Dictionary of Englishsays that O is the archaic spelling of oh, and that it’s an exclamation—that much had been clear. But for the second definition, Oxfordsays that O is used in the vocative, that is, as an invocation, in order to address something or someone.

That dual function—exclamation and invocation—makes sense for the opening line of “The Sick Rose” and numerous other poems. But something seemed amiss. If O, first and foremost, is the archaic spelling of oh, shouldn’t the two be functionally equivalent? Why, then, in its definition of oh, doesn’t Oxford mention the vocative?

Fowler’sModern English Usage only added to my uncertainty. The guide recognizes that O is an invocation, but that usage isn’t so clear for oh. And Fowlermakes a hairsplitting distinction between their uses as exclamations, something to do with “a certain independence” that oh assumes, while O “leans forward upon what follows.” It’s a matter of pausing (oh) or not pausing (O) between the exclamation and the next word.

I gave up on the language guides. Not only did they disagree about the basic functions of O and oh, but none seemed interested in the bigger question, the question of obsolescence. How do words lapse into the archaic? Why don’t we use O today?

I decided to call a few scholars and ask for an explanation. As we talked, one name kept coming up: William Wordsworth.

“Wordsworth, of course, tried to purify language. He tried to democratize it, bring it down from what had become a kind of worn out, neoclassical diction,” Douglas Kneale, a scholar of Romantic poetry, and an administrator at the University of Windsor, in Ontario, told me. “He tried to find a language really spoken by men.”

Wordsworth and his kin dismissed poetic language that included invocations like O, as well as apostrophes, according to Kneale. (An apostrophe is a device in which a speaker turns to invoke a person, thing, or idea that isn’t present.)

“There was something quite stilted, stylized, formulaic,” he said. “And so apostrophes often were the object of satire among poets.”

This trend didn’t end with the Romantics. Literary modernism also tended to deflate classical verse. Poets like T. S. Eliot and E. E. Cummings used O, as have more recent poets. In many cases, the use has been earnest, according to Laurence Goldstein, a poet and scholar at the University of Michigan.

“It was always too dramatic an expression of breath to suppress,” he told me in an e-mail. The vowel o has an attraction for poets, since it comes from the whole body, and can express both melancholy and joy, he wrote.

Modernist poets often used O and oh interchangeably, as do poets today, Goldstein added. But twentieth- and twenty-first-century poets also used O satirically, draining its emotional gravity and treating it as a cutesy anachronism.

“With modernism, the idea was that you had to strip away overused and affected poetic diction,” Goldstein told me.

That’s why in recent poetry, Goldstein said, O is often spoken by poets’ characters, not in the voices of poets themselves. He reminded me that Sylvia Plath’s poem “Lady Lazarus” has a classical O.

“But that’s not Sylvia Plath speaking,” he said. “It’s Lady Lazarus, or Plath putting on her mask or persona as Lady Lazarus.”

All of which sounded right and intellectually comfortable. That is, until I took my query to its next, logical step and tried to understand why anyone feels the needto change language in the first place.

The question, I realized, is as much one for linguists as it is for anthropologists. Thankfully, Julie Andresen, a linguist at Duke University, was able to help.

Language changes for a number of reasons. A simple one is invasion. South America, of course, wasn’t always a hot spot for Spanish. Language can also work like a broken faucet. Its rules leak, owing to mispronunciations and imperfect communication, among other reasons.

“Language is not a steady-state system,” Andresen told me—which went some way toward explaining why the modernists had rejected classical values, and why, on the most fundamental level, people and cultures change.

“Only systems in perfect equilibrium don’t change. All of these are nonstable systems,” Andresen said. Within this chaotic, unpatterned system—of language and culture—some of the change we witness comes from fashion, she said. Just as Americans have sworn off bell-bottoms, so too have we sworn off groovy. And so too did Wordsworth and the modernists dismiss classical diction.

Of course, language also represents certain values—political, aesthetic, or otherwise. And people tend to align themselves with others who share their values. They form groups. In doing so, they mark their identities, both individually and as group members, with language. Slick corporate CEOs talk this way; disillusioned street punks talk that way.

But even more, values change. Languages splinter. And some groups—with their distinct languages—wield a greater influence than their peers or predecessors.

Which, I came to realize, largely explained the issue. It was simple, in a way. Wordsworth and the modernists gained influence. Their language won. O lost.

I felt a sense of tragedy as I considered this loss. Yes, languages change, as do cultures. But O hadn’t just been replaced by oh. The transliteration wasn’t perfect.O seemed to have a unique emotional resonance. Its speakers, I thought, were desperate and alone, enfeebled somehow, and yet joyously willing to confront powers beyond their control.

Now we’re almost entirely left with oh. As in, “Oh, I didn’t know the printer paper was out.” We seem to have lost something, an underlying sentiment that was unique to O.

I asked Andresen if I was right. She unambiguously agreed that this is possible. The replacement of O with ohis in some ways a translation, she said, and underlying sentiments can be lost in translation.

I thought about this for a few days. I couldn’t help but consider the destruction we’ve welcomed in our lives—our dismissed literary traditions, the ceaseless irony and self-contemplation that mires so much artistic ambition. And yet I thought about renewal. And I tried, maybe successfully, maybe not, to contemplate the fundamental reasons that humans change.

If I have an answer, it’s that we believe we can best our forebears. We strive for perfection, in our language and sciences and culture, and this ambition can require a renunciation of the past—or at least a belief that our ancestors’ work is incomplete.

O, I think, had to make space for new ambitions, new literary life.

At the end of our conversation, Andresen asked me how long O had been in use. I told her it surfaced sometime around the 1500s. She suddenly sounded cheery.

“Well, it had a pretty good run,” she said. I agreed that it had, and I laughed, and she laughed with me.

Gabe Rivin is a freelance reporter who has written for The Atlanticand Discover, among other publications. Follow him on Twitter at @GabeRivin.