BOOKS OFTEN FALL into penumbral areas of reception and Michael Cunningham seems to have been aware that a version of this fate might await his novel “Specimen Days,” published in 2005, seven years after the Pulitzer Prize-winning “The Hours” made him a household name: Whatever he wrote after “The Hours,” he is reputed to have said, was going to be hated. It’s not that “Specimen Days” was excoriated in the press and elsewhere, but despite being a bolder book, both formally and in its themes and meanings, it did indeed struggle to emerge from the shadow of its more celebrated predecessor.

“The Hours” (1998) is divided into sections pivoting among its three central characters, Clarissa “Mrs. Dalloway” Vaughan, nicknamed by her beloved friend Richard for the 1925 novel by Virginia Woolf; Laura Brown; and Woolf herself. Part of the adventure and joy of reading “The Hours”is experiencing how these three narrative lines, each set in its own historical period, interlace, collide and amplify, making contrapuntal music. “Specimen Days” is a more neatly bounded triptych novel, the sections discrete rather than braided. Here, too, each is set in a different time period. Each is also a different genre: The first, “In the Machine,” set in a mid-to-late-19th-century New York City, is historical fiction; the second, “The Children’s Crusade,” unfolds in a post-9/11 New York City and takes the form of a thriller; and the final section, “Like Beauty,” is straight-up sci-fi, its protagonist a sentient android and its story playing out in a dystopian future where creatures from another planet live as second-class citizens in the now fragmented country that used to be a federation called the United States of America.

All the usual connective tissues of plot, continuous characters or narrative between each story have been removed; instead, the three cohere through ideas, repeated images, hauntings, motifs, echoes, quotations. An example: A white china bowl with tiny blue figures along its rim is purchased, in the first story, from a poor boy on Broadway; the same bowl is bought after the passage of at least a century by the protagonist of the second story in a tatty Broadway shop called Gaya’s Emporium; it resurfaces in the final story, this time procured from an indigent elderly woman on the streets of Denver and taken on a journey to another planet. The unity is poetical, metaphorical, different from the music of “The Hours.” Think of it as a musical suite in three movements. It encourages us to look for meaning elsewhere — in adjacency, or collocation: When the discontinuous and different stories are arranged, in the chronological order of the narratives’ unfolding, a pattern different from a continuous narrative development emerges. It invites us to step back and look for a different principle of coherence and unity, for how the parts make a sum and, crucially, what kind of a sum.

“IN THE MACHINE” is the story of a nearly 13-year-old boy, Lucas, and his recently deceased older brother Simon’s fiancée, Catherine, who works in a garment sweatshop close to Washington Square Park. Lucas has a few defining traits, the first of which, apparent from the very beginning, is the spooky way lines from Walt Whitman’s poetry collection “Leaves of Grass” (1855) come tumbling out of him. In the quiet of the house after Simon’s wake, he says to Catherine, “‘I have heard what the talkers were talking, the talk of the beginning and the end. But I do not talk of the beginning or the end.’” “He hadn’t meant to speak as the book,” we’re told. “He never did, but when he was excited he couldn’t help himself.” Understandably, the people he is speaking to find this baffling and strange, but then Lucas is a strange child, a “misshapen boy with a walleye and a pumpkin head and a habit of speaking in fits,” not unlike people who in the Middle Ages were called holy fools.

Lucas replaces Simon in the job that took his life — feeding metal rectangles to a machine that stamps them so that they can then be used as housings. In fact, he is stationed at the same machine that swallowed his brother. Cunningham notes the mind-numbing repetitiveness of the job, but any sidelong glance at Dickens is almost immediately averted by the different emphasis Cunningham brings to the juxtaposition of man, machine and mechanistic labor. The locus of his interest can be found in the way he consolidates the peculiarities of Lucas: The child begins to hear, emanating from the machine, the voice of the ghost of his brother, who it has ingested. As Lucas listens closely to the machine’s song, he comes to believe that “Simon was imprisoned in the machine. It made sudden, dreadful sense. … His ghost had snagged on the machine’s inner workings; the machine held it as a dog might hold a man’s coat in its jaws after the man himself had escaped.” An original interpretation of Gilbert Ryle’s “ghost in the machine,” then, but with a twist: Through a series of reasonings peculiar to his way of thinking, Lucas will come to a highly original understanding that Simon’s ghost in the machine wants Catherine, “want[s] to marry her in his new world if he could no longer do so in the old. He was singing to her, searching for her, hoping she might go to him.” And so Lucas, who feels his defective heart as an emptiness, an absence of soul, finds a mission: to save Catherine from the maws of the sewing machines in her sweatshop, which surely must be calling to her as Simon’s stamping machine beckons to him.

Then there’s an exhilarating lurch, as if we are traveling in a janky car except that the car turns out to be a rocket; and we are in a kind of vehicle — a time machine shooting us forward about a century. When that machine deposits us in the second section, we begin to see what has been carried over from the first — the names of some of the principal characters, the salient presence of a physically impaired child, involuntary visitations of images and phrases inside a character’s head during moments of stress and Whitman’s poetry — but all rearranged in entirely different relational connections to create a different musical score altogether. Cat Martin, a Black detective in the deterrence unit investigating a series of suicide bombings carried out by children in New York City, is the lover of a rich, white and handsome man, Simon. It is Cat who receives the phone calls from the children, warning of an imminent attack; one of the children quotes Whitman to her. When the supposed mastermind of one of these terrorist cells is caught, it turns out to be a woman whom the children call Walt Whitman. She takes in poor, abandoned, abused, sometimes deformed babies, raises them in an apartment on Rivington Street whose walls are papered over with pages from “Leaves of Grass” and arms them with homemade explosives for the advancement of their mission: a reversion to a purer, less exploitative form of living. As she declares during her interrogation, “It’s time to move back to the country. It’s time to live on the land again. It’s time to stop polluting the rivers and cutting down the forests. It’s time for us to live in villages again. … I’m part of the plan to tell people that it’s all over. No more sucking the life out of the rest of the world so that a small percentage of the population can live comfortably.”

In the first section, Lucas runs into the real Walt Whitman on Broadway one evening. The poet sends the boy on a walk beyond the boundaries of the city: “‘Go up to the edges of the city and beyond. Go see where the buildings diminish and the grass begins.’” It is as if we’ve encountered the same impulse, the same directive, in the second story, refracted through a warped glass pane; the end remains identifiable, but the means are utterly transformed.

Cat goes to find the lost boy, who’s armed to his teeth and brings to mind Lucas: “He was barely three feet tall. It was impossible to tell, in the big jacket, how deformed he might or might not be. The eyes were slightly too big, the mouth too small. His round head was big for his frail body. It stood on the shoulders of the coat like a pumpkin. Like a picture of the moon in a children’s book.” Breaking all the rules of her job, she takes him in for the night instead of going to the police. Toward the end of the story, the boy asks her to call him Luke; it’s the name of the son she lost years ago. Something unexpected happens here, and I’m reluctant to give away the particulars, but the binary of Lucas as savior and Catherine as saved turns into a more unstable, even fissile, connection between Cat and Luke, for the saving here is provisional, and the question of who is the savior and who the saved more complicated.

Again, a giant leap over a vast crevasse of time, and we discover that the biggest and most imaginative surprises of this consistently surprising novel have been saved for the final section. In a dystopian America ravaged by a cataclysmic event — it is hinted that the coup de grâce could even have been delivered by the Children’s Crusade — the triangulation among the three central figures, Simon, Lucas and Catherine, is now transposed to an android (Simon), a misshapen boy (Luke) and an alien (Catareen). Simon is a simulo, one of a line of humanoids built for long-range space travel by a freelance inventor, Emory Lowell, working for a private company. Space travel turned out to be a dead end, the company went bust, and these simulos are now contraband material: Simon and his friend Marcus are menials working for an entertainment company, subject to drone surveillance, performing simulations of crimes in the theme park that is New York City. Meanwhile, some aliens from Nadia, the first inhabited planet humans managed to reach (and were disappointed by since the harsh, backward place had no resources that they could turn a profit from), live on Earth, their movements strictly policed. Simon goes on the run with one such Nadian, Catareen, a mysterious, laconic, green lizard-woman who exercises an extraordinary fascination over him. They are joined by Luke, whose mother took Exedrol while pregnant with him under the mistaken belief that she would receive monthly reparation checks as a result. They are headed to Denver, where Simon thinks he can find Lowell and ask him a few questions about something inexplicable happening to his circuitry, a certain new sensation, a “floaty, sleeplike electrified thing.”

I don’t want to give away how the story moves toward its immensely affective climax, but Simon discovers that Emory Lowell, married to a Nadian woman who knew of Catareen on their home planet, has rigged up a spaceship in his backyard and is about to go with a ragtag crew in search of another habitable planet. Lowell sheds some light on Simon’s origins, too — besides building in an override for any kind of violence or harmful feelings these humanoids might be prone to, the scientist also put a poetry chip in this third line of humanoids, to “give [them] some moral sense … if [they] were programmed with the work of great poets, [they’d] be better able to appreciate the consequences of [their] actions.” Hence, Simon spouting Whitman, and his friend, Marcus, whom we encounter in the beginning of “Like Beauty,” quoting Emily Dickinson. But they were endowed with more than just poetry; Simon is shown to have self-awareness in the way he perceives his lack of something that biological humans have, something that Catareen mysteriously terms “stroth.” As he says to Lowell, “I have this sense of a missing part. Some sort of, I don’t know. Engagement. Aliveness. … I feel like biologicals just wallow in it. I mean it falls over them like rain, and I’m walking through the world in a spacesuit. I can see everything perfectly, but I don’t quite connect with it.”

He will make a fateful choice and underpinning the choice will be a nonpurposive, nontransactional kindness, an emotional generosity that does not lead to any kind of utility maximization (and in fact may be inimical to the very idea of self-interest), but also the sort of inexplicable, irreducible surplus apparent in the way humans (“biologicals”) feel, think, act: We see, then, that Simon has developed consciousness and, crucially, the ability to feel emotions, empathy, love, terror, regret. The idea that Cunningham introduces earlier in his literalization of the ghost in the machine here flowers fully into meaning. In his way, the author nails the Cartesian dualism that Ryle had in his cross hairs when he formulated his critique. Cunningham returns the word ghost to its earliest meanings: the Old English word “gast,” from which we derive ghost, connoted breath, spirit, soul, and was often understood as a rendering of the Latin “spiritus” (this sense survives in the term Holy Ghost, which is interchangeable with Holy Spirit). The ghost in this machine is nothing short of the origin of consciousness, of the humanoid witnessing the birth of a soul, of emotions and feelings inside him.

Throughout the novel, characters yearn for something beyond themselves, a surplus, if you will, extending past the fundamental facts and necessities of their lives. They’re all looking for a kind of transcendence, be it of the limits of the self, of the existential demands that work may place upon them, of even a (literal) hard-wiring. It is this search that makes the three narratives cohere. In the first section, Lucas looks at the constellations above and, once outside the boundaries of the city center, the grass beneath him, feels the wind, and understands that he is part of a bigger creation, as Whitman’s book tells him every night: “He felt what he knew as the rising of his self, the shifting innerness that yearned and feared … What he’d thought of as his emptiness, his absence of soul, was only a yearning for this.” Shortly after this discovery of the soul — aligned to a mystical-aesthetic appreciation — he makes a decision, like Simon in “Like Beauty,” that is bigger than himself, a decision based on how he can augment the life of someone he loves. In “The Children’s Crusade,” Cat, too, makes a choice that could either save the life of someone damaged or destroy her own. Each of these decisions is a gamble along that knife’s edge of the self versus the other. And each decider arrives at this point after a scrupulous, often revelatory act of noticing that which underscores the porosity of the self in relation to something outside it, whether the order of nature and the cosmos, another person or an alien.

ALL WRITING IS a conversation with writing that has come before and writing that is yet to come. Instead of burying this idea in his texts in a way that any exhumation of it could conceivably be seen as a critic’s interpretive dexterity, Cunningham wears it on his sleeve with pride: If “The Hours” is his conversation with Woolf, then “Specimen Days” is his interlocution with Whitman, about whom Ezra Pound once said, simply, “He is America.” The italicization is important: A poet more iconic, more conterminous with the idea of America cannot be easily found. The particular Whitman text in question is “Specimen Days & Collect.” First published in 1882-83 (so, almost coincident with the period in which “In the Machine” appears to be set) and later renamed “Specimen Days in America,” it is a miscellany book consisting of brief pieces — diary entries, jottings, observations, vignettes, drawn over the course of two decades — on a multitude of subjects, from the meadow lark to the essayist Thomas Carlyle. Earlier in the book there is a series of vivid first-person reports of the Civil War. There is Whitman’s account of the first Battle of Bull Run, in which the Unionists were defeated; there are moving and often tragic sketches of the wounded and the author’s experience of tending to them (these, of course, not without frequent homoerotic frissons); there’s a short profile of Abraham Lincoln that begins, delightfully, “I see the President almost every day, as I happen to live where he passes to or from his lodgings out of town.” Whitman writes, too, of the staggering number of army deserters, which “have often averaged 10,000 a month.” But for this reader, the book’s extraordinary achievement lies in its nature writing. Fine-grained and lyrical in a way that brings to mind the journals of the poet Gerard Manley Hopkins, the entries on birds migrating at midnight, on bumblebees and horsemint and cedar apples, on the scent of clover and hay, on crows and “loafing in the woods” and nights spent on the Mississippi River, on immense fields of bright yellow coreopsis flowers in Missouri, are all marked by a luminous, almost incandescent, attentiveness. The unique stripe of transcendence Whitman espoused sprang from the scrupulous, respectful attention one brought to bear upon the world. We are reminded that the word specimen, after all, derives ultimately from the Latin “specere” — to look.

By echoing the title of a miscellany about the very particulars that, aggregated, make both the idea and the experience of a nation, Cunningham inscribes his own novel into the Whitmanesque space for meditation about what constitutes the soul of America. It’s a breathtakingly bold and confident gambit, one that pays off in the subtle, unlabored valorization of attention that emerges by the end of both books. One notices, therefore one is, both authors declare. It’s a foundational moral act.