Ever since the Renaissance, the sciences have dealt human beings a steady stream of humiliations. The Copernican revolution dismantled the idea that humanity stood at the center of the universe. A cascade of discoveries from the late-18th to the early-20th century showed that humanity was a lot less significant than some had imagined. The revelation of the geological timescale stacked millions and billions of years atop our little cultural narratives, crumbling all of human history to dust. The revelation that we enjoy an evolutionary kinship to fish, bugs, and filth eroded the in-God’s-image stuff. The disclosure of the size of the galaxy—and our position on a randomly located infinitesimal dot in it—was another hit to human specialness. Then came relativity and quantum mechanics, and the realization that the way we see and hear the world bears no relation to the bizarre swarming of its intrinsic nature.

Literature began to taste and probe these discoveries. By the 19th century, some writers had already hit upon the theme—meaninglessness—that would come to dominate the 20th century in a thousand scintillating variations, from H. P. Lovecraft’s Cthulhu stories to Samuel Beckett’s plays. But by the turn of the new millennium, it had become clear that this sense of meaninglessness was no longer up to date.

In 1961, Frank Drake developed an equation with a string of variables to try to determine the frequency of intelligent life. Over the years, some of the variables have been plugged in. Maybe planets are just very rare? They’re not. Perhaps few planets orbit their star in the “Goldilocks zone” where it isn’t too hot or cold? No, it seems that lots do. This may sound like another round of Copernican humiliation: In a galaxy with up to 400 billion stars, many with orbiting planets, surely there’s some other intelligent, technological species. But humans have been scanning the spectra for decades and have found nothing.

Earlier this year, a group at the University of Oxford released a paper arguing that our knowledge of the universe and of math should lead us to assume that intelligent life is most probably an extremely rare event, depending on a series of fortuitous circumstances—like the weirdly large size of our moon, perhaps— that are so unlikely as to almost never happen. Humanity shouldn’t be surprised that we haven’t found aliens, because most likely there aren’t any.

But, seriously, where are the aliens?

It’s important to note that these arguments depend on probabilities, and that our search for intelligent life in the cosmos is still woefully incomplete. But even so, it looks increasingly possible that humans may indeed be alone, or that we might have some mind-bogglingly gigantic region of the cosmos to ourselves. As this idea slowly seeps into our consciousness, it’s going to have deep cultural consequences. The mental habits of two centuries will lead us to strenuously resist this new picture of the galaxy, especially since, from ancient myths to postmodern sci-fi, humanity has almost always understood itself in relation to a nonhuman or superhuman Other.

If the revelation that humans are probably alone in our universe stands, and as that revelation sinks into our collective psyche, it could effect a second, weirder Copernican revolution in culture. To begin with, it’s really hard to square humanity’s status as perhaps the only intelligent species in all of time and space with the idea that we are insignificant. To the contrary, the everyday breath of the least of us contains meaning in so concentrated a form that a cup’s worth of it could be doled out to a dozen star systems, transforming the arid matter into a garden of significance.

There’s been a lot of talk in literary and philosophical circles of a new “post-secular” age. And some writers, like Marilynne Robinson in her stunning novel Gilead, have discovered old religious skins for the new wine of our time. But in truth, human culture never left the non-secular world behind. The 20th-century fantasies of alien intelligence were just a modern version of religious literature. Religion, after all, conceived of a relation between two intelligences—one human, one not. Books from Arthur C. Clarke’s Rendezvous With Rama to the Strugatsky brothers’ Roadside Picnic to basically all of the late Philip K. Dick recast the ancient story of humanity’s contact with an unknowable god in the terms of alien intelligence. If humankind begins to see intelligence as one thing—just us—then religion’s service to secular literature may finally be at an end.

Humanity won’t find it easy to let it go. At least since William Gibson’s Neuromancer, writers and filmmakers have attempted to replace the alien/god figure with artificial intelligence. But several considerations temper the long-term viability of this solution. First, it’s unclear when—or even if—humanity will achieve genuine AI. But even if it does, an artificial mind might not be sufficiently different from its human designers to constitute a genuinely alien kind of intelligence. One like the god machines of The Matrix, say, rather than just a weirder version of human thought. Almost anything is possible. But if it’s not likely that aliens will take the place of God, then it’s also unlikely that AI will. Our most probable, foreseeable future is occupied by a single, human intelligence, even if it’s one adorned with artificial tools and enhancements.

If secular culture eventually gives up the vestigial trappings of alien or artificial gods, it need not sacrifice their mystery in the process. The singularity of human intelligence has a paradoxical quality of its own.

Individuals obtain their identity through relations with others. If there were no other people, you wouldn’t know what kind of person you are. When I was little, I used to pretend my parents’ tiny lawn was the map of an imaginary nation. I told another child this, and they laughed at me. It had a surprising impact on my identity, in the moment and over time. If the other child had instead looked at me and whispered, “Me too,” that would have shaped my sense of self in a different way. Naturally, more solemn versions of that event manifest themselves through race and gender, among other markers of identity. Through encounters with others, the molten, fluid self begins to cool and harden.

But if there is no other, you have no identity. In the science fiction of the future, the future in which humanity stands alone at the center of all meaning in space and time, we may begin to lose our shapes. Right now, at this moment, human identity is beginning to dissolve and change. What kinds of stories will we tell about our species when we no longer expect some other—an alien, a god—to tell us who we are?

In countless science fictions—from The War of the Worlds to the Syfy series The Expanse—an alien invasion invites the Earth’s squabbling peoples to realize their common humanity. But if there is no alien, it may become harder to see what an American and a Russian, or a New Yorker and an Alabaman, have in common. One path our future literature might take is to transfer alienness from different extraterrestrial species to different terrestrial cultural groups. Such a literature could draw on the rich vein of writing—from Edmund Burke to Toni Morrison—that depicts people as bound so tightly to the literal and metaphorical soil of their origin that communication across cultural, racial, national, or sexual borders becomes as fraught and difficult as communication across different species. Every day, we see this mode of thinking at work in our culture.

But maybe there’s another way. A couple of years ago, I was exploring ideas for a science-fiction novel. I’d been playing around with a first-contact plot, but I got stuck. I just didn’t believe in aliens anymore. They seemed so unreal. There’s something retro about aliens, I thought, a vestigial remnant of the 20th century, like DeLoreans. I sat there thinking about how one could write a sci-fi novel without extraterrestrials. Then I thought—this is a weird thing I’m doing right now. Thinking. What is this? What does it feel like? I closed my eyes, felt the thoughts whispering around in my skull, whispering to themselves. I opened my eyes, looked at the familiar organic forms of my backyard—the grass, the bark of a tree, my own arms and hands. And all the time these thoughts, darting among these things, into them—exiting swiftly—invisible tongues tasting the earth.

We can be our own alien, I thought. All humans participate in this strangeness of thinking. The idea embedded like an invader in my flesh. I began to write, and a new set of problems opened up. When I thought I wanted to create a story about extraterrestrials, I was trying to invent something unfathomably different—and then give it just enough familiarity to enable readers to grasp it. Now I had the opposite problem—taking something that was the definition of familiar—human thought—and awakening a sense of its cosmic strangeness. For a long time, I simply observed. Watching the flicker of my own thoughts, I became convinced that, as the poet Elizabeth Bishop put it, “nothing stranger could ever happen” than to wake up and find oneself a human being.

Now looking back on that moment from the perspective of the Oxford study’s revelation, I wonder if giving up gods and aliens will lead people to the weird singularity of the human mind. Our species hosts what is probably the only example of technological intelligence. The human brain will most likely remain the most complex organization of matter in the universe. And all of us manifest this intelligence—this entity alien to the rest of space and time. The weird thing, the mysterious and story-provoking thing, isn’t that we have too little meaning. It’s that we have too much of it. It seems out of place in a silent galaxy. That’s the idea we’ll have to get used to. Newly rich with galactic meaning, humankind is finally free to see its loneliness as awe-inspiring rather than tragic.