My favorite aunt, Auntie Len, when she was in her eighties, told me that she had not had too much difficulty adjusting to all the things that were new in her lifetime—jet planes, space travel, plastics, and so on—but that she could not accustom herself to the disappearance of the old. “Where have all the horses gone?” she would sometimes say. Born in 1892, she had grown up in a London full of carriages and horses.

I have similar feelings myself. A few years ago, I was walking with my niece Liz down Mill Lane, a road near the house in London where I grew up. I stopped at a railway bridge where I had loved leaning over the railings as a child. I watched various electric and diesel trains go by, and after a few minutes Liz, growing impatient, asked, “What are you waiting for?” I said that I was waiting for a steam train. Liz looked at me as if I were crazy.

“Uncle Oliver,” she said. “There haven’t been steam trains for more than forty years.”

I have not adjusted as well as my aunt did to some aspects of the new—perhaps because the rate of social change associated with technological advances has been so rapid and so profound. I cannot get used to seeing myriads of people in the street peering into little boxes or holding them in front of their faces, walking blithely in the path of moving traffic, totally out of touch with their surroundings. I am most alarmed by such distraction and inattention when I see young parents staring at their cell phones and ignoring their own babies as they walk or wheel them along. Such children, unable to attract their parents’ attention, must feel neglected, and they will surely show the effects of this in the years to come.

In his novel “Exit Ghost,” from 2007, Philip Roth speaks of how radically changed New York City appears to a reclusive writer who has been away from it for a decade. He is forced to overhear cell-phone conversations all around him, and he wonders, “What had happened in these ten years for there suddenly to be so much to say—so much so pressing that it couldn’t wait to be said? . . . I did not see how anyone could believe he was continuing to live a human existence by walking about talking into a phone for half his waking life.”

These gadgets, already ominous in 2007, have now immersed us in a virtual reality far denser, more absorbing, and even more dehumanizing. I am confronted every day with the complete disappearance of the old civilities. Social life, street life, and attention to people and things around one have largely disappeared, at least in big cities, where a majority of the population is now glued almost without pause to phones or other devices—jabbering, texting, playing games, turning more and more to virtual reality of every sort.

Everything is public now, potentially: one’s thoughts, one’s photos, one’s movements, one’s purchases. There is no privacy and apparently little desire for it in a world devoted to non-stop use of social media. Every minute, every second, has to be spent with one’s device clutched in one’s hand. Those trapped in this virtual world are never alone, never able to concentrate and appreciate in their own way, silently. They have given up, to a great extent, the amenities and achievements of civilization: solitude and leisure, the sanction to be oneself, truly absorbed, whether in contemplating a work of art, a scientific theory, a sunset, or the face of one’s beloved.

A few years ago, I was invited to join a panel discussion about information and communication in the twenty-first century. One of the panelists, an Internet pioneer, said proudly that his young daughter surfed the Web twelve hours a day and had access to a breadth and range of information that no one from a previous generation could have imagined. I asked whether she had read any of Jane Austen’s novels, or any classic novel. When he said that she hadn’t, I wondered aloud whether she would then have a solid understanding of human nature or of society, and suggested that while she might be stocked with wide-ranging information, that was different from knowledge. Half the audience cheered; the other half booed.

Much of this, remarkably, was envisaged by E. M. Forster in his 1909 story “The Machine Stops,” in which he imagined a future where people live underground in isolated cells, never seeing one another and communicating only by audio and visual devices. In this world, original thought and direct observation are discouraged—“Beware of first-hand ideas!” people are told. Humanity has been overtaken by “the Machine,” which provides all comforts and meets all needs—except the need for human contact. One young man, Kuno, pleads with his mother via a Skype-like technology, “I want to see you not through the Machine. . . . I want to speak to you not through the wearisome Machine.”

He says to his mother, who is absorbed in her hectic, meaningless life, “We have lost the sense of space. . . . We have lost a part of ourselves. . . . Cannot you see . . . that it is we that are dying, and that down here the only thing that really lives is the Machine?”

This is how I feel increasingly often about our bewitched, besotted society, too.

As one’s death draws near, one may take comfort in the feeling that life will go on—if not for oneself then for one’s children, or for what one has created. Here, at least, one can invest hope, though there may be no hope for oneself physically and (for those of us who are not believers) no sense of any “spiritual” survival after bodily death.

But it may not be enough to create, to contribute, to have influenced others if one feels, as I do now, that the very culture in which one was nourished, and to which one has given one’s best in return, is itself threatened. Though I am supported and stimulated by my friends, by readers around the world, by memories of my life, and by the joy that writing gives me, I have, as many of us must have, deep fears about the well-being and even survival of our world.

Such fears have been expressed at the highest intellectual and moral levels. Martin Rees, the Astronomer Royal and a former president of the Royal Society, is not a man given to apocalyptic thinking, but in 2003 he published a book called “Our Final Hour,” subtitled “A Scientist’s Warning: How Terror, Error, and Environmental Disaster Threaten Humankind’s Future in This Century—on Earth and Beyond.” More recently, Pope Francis published his remarkable encyclical “Laudato Si’, ” a deep consideration not only of human-induced climate change and widespread ecological disaster but of the desperate state of the poor and the growing threats of consumerism and misuse of technology. Traditional wars have now been joined by extremism, terrorism, genocide, and, in some cases, the deliberate destruction of our human heritage, of history and culture itself.

These threats, of course, concern me, but at a distance—I worry more about the subtle, pervasive draining out of meaning, of intimate contact, from our society and our culture. When I was eighteen, I read Hume for the first time, and I was horrified by the vision he expressed in his eighteenth-century work “A Treatise of Human Nature,” in which he wrote that mankind is “nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a perpetual flux and movement.” As a neurologist, I have seen many patients rendered amnesic by destruction of the memory systems in their brains, and I cannot help feeling that these people, having lost any sense of a past or a future and being caught in a flutter of ephemeral, ever-changing sensations, have in some way been reduced from human beings to Humean ones.