James Kugel has been spent his entire scholarly career studying the Bible, but some very basic questions about it still obsess him. What was it about the minds of ancient Israelites that allowed them to hear and see God directly—or at least, to believe that they did? Were the biblical prophets literally hearing voices and seeing visions, understanding themselves to be transmitting God’s own exact words? If so, why did such direct encounters with God become rarer over time?

In his new and final book, The Great Shift, Kugel investigates these questions through the lens of neuroscientific findings. (The approach is reminiscent of other recent books, like Kabbalah: A Neurocognitive Approach to Mystical Experiences, co-written by a neurologist and a mysticism scholar.) First, Kugel uses biblical research to show that ancient people had a “sense of self” that was fundamentally different from the one modern Westerners have—and that this enabled them to experience and interpret prophecy differently than we do. Then he uses scientific research to show that we shouldn’t assume their view was wrong. If anything, our modern Western notion of the bounded, individual self is the anomaly; most human beings throughout history conceived of the self as a porous entity open to intrusions. In fact, much of the rest of the world today still does.

Kugel cites several studies showing that even now, many healthy people hear voices—as much as 15 percent of the general population. He also cites a recent cross-cultural study in which researchers interviewed voice hearers in the United States, Ghana, and India. The researchers recorded “striking differences” in how the different groups of people felt about the voices they hear: In Ghana and India, many participants “insisted that their predominant or even only experience of the voice was positive. … Not one American did so.”

“These results,” Kugel concludes, “would suggest that a society’s ‘givens’ have a lot to do with how voice hearing is interpreted”—cultural conditioning impacts whether a phenomenon like prophecy will be celebrated or pathologized. Our conversation about that phenomenon, which follows below, has been edited for clarity and length.

Sigal Samuel: The central claim of your book, to me at least, is that people in biblical times had a very different “sense of self” than we do in the modern West. Can you explain what you mean by that?

James Kugel: Anthropologists who have studied cultures that are very different from ours—in sub-Saharan Africa, South America, and elsewhere—have come to focus increasingly on this elusive item. A people’s “sense of self” is the idea that they carry around in their heads about who “I myself” am and how I fit into the larger world. What it consists of turns out to vary greatly from one society to another and from period to period.

For the most part we tend to assume that biblical figures have the same sense of self as we do. So when the Bible says that God appeared to Abraham outside his tent or called to Moses out of a burning bush, we have to dismiss such things as some sort of figurative language, or else we just shrug them off: Such things happened “back then” but they don’t anymore.

But if we go back far enough in biblical history, ancient Israelites seem to have conceived of themselves in terms very different from our own. Getting inside their minds, seeing things the way they saw them, is the key to understanding what the Bible is trying to get across.

Samuel: You write that we envision our minds as self-enclosed entities, which outside forces don’t penetrate at will, but that ancient Israelites operated with a model of a “semipermeable mind.” What evidence in the biblical text suggests that?

Kugel: I made up this term to try to get at the reality that ancient Israelites experienced, or at least found utterly plausible. The human mind could be penetrated by outside forces. Not only by God—who is sometimes depicted as going inside people, “probing their kidneys and heart” to find out what they’re really thinking—but by various sorts of “spirits.” Some of them were benign, but others were wicked spirits dispatched by Satan to take over. They were like bacteria; you couldn’t see them, but once they got inside of you they would take charge, making you think and do things against your will. So the Bible and other texts from the same period contain prayers specifically designed to ward off these evil spirits. That’s part of what I meant by semipermeable. You couldn’t stop God from entering your mind, but sometimes you could head off a wicked angel.

Samuel: What do neuroscientists have to teach us about the semipermeable mind and how common it was—and is—as a construct?

Kugel: This was the part that most amazed me. We tend to think that there is some central part of our brains that acts as a clearinghouse, processing all the outside sensory data that come into our heads via our eyes and ears and so forth and then deciding what to think and how to respond. The problem with this picture is that scientists cannot find anything physical in the brain that seems to act as the clearinghouse. In physiological terms, there is no “I myself”; such an entity seems to be a mental construct, something human beings evolved over millions of years but which has no independent, physical reality. This “I myself” is not, we believe, identical to our bodies or our brains—we have a body and a brain, but the possessor of these things is somehow conceived to be separate from them, some fictional owner, me. This, as far as most neuroscientists are concerned, is simply a mental construct. Science doesn’t need an “I myself” to explain what goes on in our brains, but apparently we do.

Samuel: You also draw on anthropological findings to support the idea that the porous self was actually the dominant construct for most of history and is still dominant in parts of the world. Can you give an example?

Kugel: I was particularly affected by one anthropologist’s description of the Dinka people of southeastern Sudan. They have, he wrote, nothing that corresponds to our idea of the mind as mediating or remembering our experiences. In other words, there is nothing “in here” that stands between whatever happened out there and who I am right now. That outside thing just keeps on being there, and there is no “I myself” to put it into perspective or move it into the category of memory.

One of the Dinka he studied reported that, after having been imprisoned in Khartoum, named one of his children Khartoum, in part to protect himself from any future misfortune that might come from that place. Khartoum was the still-active actor, and the man was merely an object that potentially might be acted upon again.

Samuel: How does the model of the semipermeable mind help us understand what the biblical prophets understood themselves to be doing? Were they literally hearing voices?

Kugel: Even today, people hear voices. Some of them are homicidal maniacs, but others lead perfectly normal lives, they just hear people who aren’t there. They even have an organization, the Hearing Voices Movement, with an annual convention of hundreds of voice hearers. I got interested in this because I wanted to know what made biblical prophets say what they always say—“God told me to tell you this.” It’s hard to know, but it seems possible that at least some of them meant precisely that. Of course, as other scholars have argued, the whole phenomenon of biblical prophecy also had a lot to do with the surrounding society and its openness to having a prophet in its midst.

Samuel: I find that point about cultural conditioning really useful. In the book, you write about the prophet Jeremiah: “Perhaps it was his society’s own assumptions—about the reality of prophecy itself, and along with this, the very sense of self that Jeremiah and his fellow citizens shared—that enabled him to hear a voice to which, in other circumstances, his ears might have been altogether deaf.”

And presumably that applies not just to hearing voices, but also to seeing visions. Nowadays a lot of people would call the prophets’ experiences “hallucinations” and pathologize them, but it seems like that wasn’t the case in biblical times.

Kugel: I like the definition of hallucination recently proposed by a neuropsychiatrist; it’s not something false, he wrote, but a “sensory experience which occurs in the absence of corresponding external stimulation of the relevant sensory organ.” This, I think, is what some biblical texts are talking about. The person thinks he’s seeing or hearing something, but it seems to work a little like a dream. In a dream, the dreamer processes whatever he’s dreaming as if it’s coming from the outside, with his eyes darting around behind his eyelids. When the dreamer wakes up, he’ll say, “I saw a woman wearing a red dress, it looked as if she was coming from some party, and then I heard a scream”—but of course, his eyes were closed and his ears heard nothing. This may be a way of understanding biblical hallucinations—though it doesn’t say why people had them, or why they stopped in later biblical times.

Samuel: Why did they stop? Why have many of us lost the sense that we can see and hear God directly?

Kugel: So much of the world has changed; in fact, it had begun to change radically even within the biblical period. Ancient Israelites weren’t scientists, but they gradually developed a sense that there are rules that govern what happens in the world, and violations of those rules, miracles, became more and more infrequent. People still encountered God, but there was a definite movement from outside to inside; the soul gradually became what it had never been before, a kind of divine island in the midst of the human body. Most of all, people’s sense of self evolved; the divine no longer began where a person’s fingertips ended, and people were no longer as open to an uncanny surprise just around the corner.

Samuel: You write about us modern Westerners that “the harsh cultural conditions into which we have been born have for the most part turned our originally open, semipermeable selves into oddly stunted and closed-off organs, which today are scarcely aware of their tiny opening to the Outside.” That sounds pretty negative. Do you think people are better off when they see their minds as semipermeable? Or is it meaningless to make a value judgment about this?

Kugel: I’m not sure what a Martian’s view of our sense of self would be, but I think I have an idea of what ancient Israelites might say about us, once the shock wore off. Quite apart from our living in a world in which God plays no obvious part, they would be astounded at encountering a sense of self that is just huge, virtually filling the heavens. Each of us would seem to them so important, so big! Their sense of self was far more collective than ours; their own existence was tightly connected to that of siblings and cousins and clan-mates far and wide, and who they were was very much defined by who they came from as well as by their inherited social roles. All this, quite apart from semipermeability, simply made them much smaller than we are today. In fact, from this perspective the semipermeable mind was just another aspect of human smallness. I think the challenge facing religions in the West nowadays is to try to help people shrink down to a more realistic size, and then to let the divine take over where the human leaves off.