“What do you do when you can’t write?” Such a question is inevitably asked by an audience member in writing workshops and book talks. A collective intake of breath goes through the crowd, heads nod in sympathetic recognition, and everyone leans in to hear how the successful writer has found her words again. For authors, few things are more frustrating—or more common—than a case of writer’s block: that state of verbal paralysis when words simply refuse to flow, or even trickle, onto the page. Yet there exists a more extreme form of writer’s block, one that makes typical remedies—like going for a walk or reading for a bit—seem laughably frivolous.

Aphasia is a communication disorder that impairs the ability to speak, write, and understand language. Whether caused by a stroke, a tumor, a traumatic brain injury, or a progressive form of dementia, the mute horror of language loss and its accompanying isolation can be devastating. Yet it’s essential to think about aphasia now, and not just because it’s more common than Parkinson’s, muscular dystrophy, or cerebral palsy. Aphasia brings up existential questions that get at the heart of human connection: Who are we without language? If I were struck by aphasia today, what would be left unsaid, to my family, my friends, my readers? What secrets burden us in remaining untold? How might we express ourselves if we’ve lost our words? And for authors in particular: Is a writer without words still a writer at all?

Such fundamental questions of language, connection, and identity are explored in two new books. Carlos Fonseca’s novel Austral features a writer rendered irreversibly mute by a stroke before she managed to communicate a secret trauma of her past. James Marcus’s biography of Ralph Waldo Emerson, Glad to the Brink of Fear, recounts the life of the transcendentalist philosopher, including his final affliction with what the medical profession might now call primary progressive aphasia (PPA), a neurodegenerative condition whose pathological terminus is either Alzheimer’s disease or frontotemporal dementia. These two books exploring aphasia clarify the fleeting privilege of being able to communicate clearly, as well as the creativity needed to connect without words. At their core, Austral and Glad to the Brink of Fear are both about writing as a fundamental part of life, and about what happens when the ability to write ends before life does.

Yet even these stories don’t encompass the full scope of the affliction. The slow cruelty and surprising opportunities of communicating with aphasia have an especially keen significance for me, because my mother has PPA. As I watch her casting about for words in the newly murky waters of her mind, I’ve come to consider writer’s block—including my own—a luxury of the able-minded.

The central figure in Austral is Aliza Abranavel, a British novelist barely able to speak or write following a brain bleed. When doctors inform her that she is unlikely to recover her language abilities, she moves from New York to the Argentine desert and continues work on a complicated series of writing projects. She remains “perfectly lucid until the very end,” despite being unable to express herself with language: a kind of locked-in syndrome not unlike Jean-Dominique Bauby in The Diving Bell and the Butterfly. (I should note here that many aphasics recover some lost language skills in the months and years following a stroke or injury; only PPA is entirely irreversible.)

The novel opens some 10 days after Aliza’s death, yet her voice lives on in the enigma of her last manuscripts. These are interwoven in the novel with the story of Julio Gamboa, an old, estranged friend, whom Aliza has posthumously thrust into the role of literary executor, decades after the pair took a road trip through Central America. The plot turns on Julio deciphering Aliza’s multiple notebooks—titled A Private Language and A Dictionary of Loss—to reveal a secret about traumatic events she witnessed while working as a photojournalist in the civil war and dictatorship in Guatemala in 1982. For his part, Julio can’t remember much about the trip. So the drama of the story builds as he cracks Aliza’s oblique and highly personal codes written before and, more sparingly, after her aphasia.

Much more familiar terrain for most American readers can be found in the biography of Ralph Waldo Emerson. It describes the composition of now-classic writings such as “Self-Reliance” (1841), as well as Emerson’s close and complicated relationships with noted 19th-century luminaries Henry David Thoreau and Margaret Fuller in Concord, Massachusetts.

Written with a free-wheeling joy bolstered by rigorous research, Glad to the Brink of Fear depicts Emerson as an essentially aphoristic writer who understood the transformative power of language: “‘The maker of a sentence,’ he once wrote, ‘launches out into the infinite and builds a road into Chaos and Old Night, and is followed by those who hear him with something of wild, creative delight.” Emerson certainly gained many followers, less as a published author in his day (his writings sold poorly thanks to an incompetent publisher—every writer’s nightmare) than as a “star of the national lecture circuit.” As Marcus notes with precision, Emerson gave a total of 1,469 lectures across the country from the 1830s to the 1870s: “What he did for a living, in a very real sense, was talk.”

Emerson’s later years were full of tragic ironies. The famed speaker developed expressive aphasia, as part of what his later biographers have identified as Alzheimer’s disease. That is, Emerson could read and understand speech, but neither write nor speak coherently himself. The author of “Self-Reliance” eventually relied on his daughter Ellen to prepare and aid him in delivering his lectures, and even to compile his last books with the help of his literary executor.

Marcus calls her his “human teleprompter” and “aide-mémoire-in-crinoline,” reductive compliments that reveal how the intellectual and emotional labor of caregiving is too often gendered and glossed over. As a dutiful daughter and aphasia caregiver myself, I felt these lines as a breezy dismissal of Ellen’s work, despite Marcus’s otherwise laudable recognition of her role in preserving Emerson’s reputation and livelihood. For by the time he reached his deathbed, surrounded by future biographers and family members, Emerson “spoke in sentences that nobody could understand”: “The words meant everything to him and nothing to them.”

Aphasia brings up existential questions that get at the heart of human connection: Who are we without language?

It’s tempting to frame aphasia as a sad ending to an otherwise brilliantly verbal life, as the story of Emerson and other literary aphasics like Baudelaire and Beckett is often told. But Fonseca’s novel shows that the creativity needed to communicate as language recedes is far more compelling than the excessive verbosity (perfectly captured in the strange-sounding Spanish word verborragia) of any motormouth.

In Austral, Julio’s literary sleuthing in Aliza’s notebooks leads him from Ohio to Argentina to Guatemala. Here, he encounters Juan de Paz Raymundo, an Indigenous K’iche’ man who survived the government’s massacre of his entire village of Amajchel when he was a young boy. As a result of this trauma, Raymundo and other survivors struggle to speak about many aspects of life in the village, even the most mundane details. In a sense, they have been rendered aphasic by violence.

In an effort to unearth memories and communicate them, Raymundo constructs a Theater of Memory based on the 16th-century Italian philosopher Giulio Camillo’s plan to build a wooden theater featuring images from mythology and other visual symbols in the place of tiered seating. In Camillo’s vision, the speaker would stand on the stage of the theater and be able to recall and express all knowledge in existence, using mnemonics and mental associations with those images and symbols. The plans for Camillo’s theater went unfinished and eventually perished in a fire. But, in the 21st century, Raymundo hand-built a theater with a palm-frond roof on the grounds of the razed Guatemalan village, covering its walls with photos, weather reports, soccer match results, and other details of quotidian life before the massacre. He also installed speakers to play the oral histories of survivors describing the village. The theater of memory uses images, small-scale models, and sounds to express the history of Amajchel that is too painful for most of its people to narrate.

Through these means, the survivor Raymundo tells Julio, he has been able to recover and describe his life with his family and the events of the massacre, including the secret buried in Aliza’s journals. The theater of memory works on Julio, too, and he recalls parts of the trip he had previously blocked out. In the closing pages of the novel, Julio realizes that Aliza’s cryptic manuscripts have communicated more effectively than her voice ever did. Not only do they lead him to Amajchel, they spark a reflection on the nature of language, memory, and trauma, including his own.

Communication, then, does not end with language loss—it might even improve it. Aphasia makes us slow down and select our words with care, a sorely needed skill these days. It occasionally leads to surprising poetic flights, as Diane Ackerman noted in One Hundred Names for Love when her husband, the novelist Paul West, became aphasic after a stroke. Emerson called his dressing gown “the red chandelier”; when my own mother couldn’t come up with the word for my dog’s spiky prong collar, she called it a “garrote,” that ancient weapon of assassination consisting of a ligature tightened with a stick around a victim’s neck. I suddenly became hesitant to use the collar at all.

Aphasia can change people in the most profound ways, at times for the better. As Emerson’s verbal and cognitive capacities declined, the problematic social Darwinism at the heart of his “Self-Reliance” faded, leading him to state toward the end of his lecturing era that “there is no pure originality” and that “all minds quote.” In Austral, as the doctors explain the innerworkings of aphasia to Aliza, she intuits that “only someone who has lost the immediacy and transparency of language is capable of finally seeing it in all its opacity: stubborn, exact, hard as a rock.”

Aphasia has changed me, too. Every conversation I have with my mother matters more to me now than it used to; I no longer multitask when I’m around her, because her words require—and merit—my singular focus. I often wonder: What should I ask her right now, while she can still speak? Might she be harboring some secret that, if left unsaid, could haunt us for years?

On the other hand, like Aliza, I’ve been surprised to discover that those stubborn, opaque, hard words aren’t the sole foundation of human connection. My communication with my mother, increasingly, is moving beyond spoken language: based in touch and shared experience more than verbal expression. I’m learning to focus on what she is telling me without words.

This, then, is the gift of aphasia, and even of writer’s block: it is only in its restriction that we grasp the limits, as well as the potential, of language.