The discussion between neurosurgeon Michael Egnor and historian of science Michael Shermer at COSM 2025 last Wednesday evening was the latest in their series of friendly debates about whether we are biological machines (Shermer) or creatures with immortal souls (Egnor).
Shortly after the publication of The Immortal Mind: (2025), Shermer, author of many mainstream books and founding publisher of Skeptic Magazine invited Egnor to appear on the Michael Shermer Show alongside leading neuroscientist Christof Koch
Then, he and Egnor appeared together on Piers Morgan’s widely watched show.
So by the time they met up after dinner last week at COSM 2025, they had a clear idea what each other might say about the question: “Understanding Consciousness: Are Human Beings Machines?” That probably made the encounter more interesting for the audience.
Jay Richards, author of The Human Advantage (2018) moderated, with philosopher of technology George Gilder as a responder.
Today, I’m going to look at what Egnor, who spoke first, had to say. Tomorrow, we’ll look at Shermer’s response and then, in a third post, the whole discussion in context.
The strongest piece(s) of evidence
Egnor started by pointing out that he began his medical career as a materialist. But his clinical experience did not fit the materialist descriptions in textbooks. He cited a number of examples.
After hearing his talk, I asked him to tell me, what he considered to be the single strongest piece of evidence — among those he had discussed — that we are not machines, that we have immortal souls. He replied, offering two pieces and inviting me to pick one:
The fact that 250,000,000 seizures over the past two centuries (the era of modern neuroscience), in addition to about 400,000 awake brain mapping operations in the US over the past century, in addition to 20,000 Americans with deep brain stimulators continuously working at 60 Hz, have never once stimulated reason or free will from the brain. Only movement, sensation, memory and emotion can be stimulated from the brain. The obvious interpretation of this massive body of evidence is that reason and free will don’t come from the brain. Aristotle and Aquinas were right.
Working and studying in the area, Egnor found that stimulating the brain — or for that matter, epileptic seizures — cause four things to be evoked: perception, memory, motion, and emotion. They do not produce either rational thought or free will. And these are precisely the qualities that classical philosophy has attributed to the immortal soul (“Aristotle and Aquinas were right.”).
And the other?
Split brain operations split perception, but do not split conception. People with split brain surgery can conceptually link and compare images presented to both sides of their disconnected brains with ease and accuracy, despite the fact that no part of their brain has access to both images. This is remarkable, and shows that conceptions (abstract thought, free will, etc.) are not material powers of the soul and cannot be split surgically.
In his talk, he briefly discussed the work of Alice Cronin at MIT, which illustrates a unified mind working with a split brain:
She asked them to compare two sets of pictures and she had hundreds of different sets of pictures. These are some of the ones that she used to one hemisphere. She would show them a picture of a violin to the other hemisphere. She would show them three pictures. One picture would be an artist’s palette, the other would be a toilet plunger, and the other picture would be a stethoscope. And she’d say of the three pictures, which one conceptually matches the one picture? And people with split brain surgery immediately say, oh, well the violin has matched the artist palate because they’re both forms of art.
But this is what gives me chills. No part of these people’s brains has seen both things. One hemisphere saw the violin, the other hemisphere saw the artist’s palate. How can they compare them? … They don’t seem like they’re from the brain and they’re not split by a surgeon’s knife.
In general, he noted, people with split brains and largely absent brains can lead normal lives, contrary to what materialism would lead us to expect. “I could have had split brain surgery and you couldn’t tell the difference. I couldn’t tell the difference except I’d have fewer seizures.”
What exactly is the soul?
Egnor discussed near-death experiences but — perhaps sensing that Michael Shermer would take up the question in his response talk — he focused toward the end on an accurate understanding of the soul.
The soul, traditionally speaking, is everything that distinguishes a live body from a dead body, whether we are talking about a cat or a human being. What makes the human being different is that some elements of the human soul — reason and free will — are immortal. They are not, as Egnor showed, simply products of the brain:
When you die, your body does not disappear, it disintegrates. All the atoms still exist but they are repurposed as something else. The soul, however, cannot disintegrate. It is more like the number 8 than it is like the body. It has no physical substance or location.
So the immaterial powers of the soul, which are reason and free will cannot disintegrate, which means your soul is immortal. What happens after death and what immortality means is a whole separate question.
In The Immortal Mind, we pointed out that the soul cannot dis-integrate because it is not integrated in the first place. It is an indivisible immaterial unity.
And then it was Michael Shermer’s turn … And then GeekPlanet News asked some questions.
