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Bernardo Kastrup on the Nature of Reality: Materialism, Idealism, or Skepticism

Science Ideated: The Fall Of Matter And The Contours Of The Next Mainstream Scientific Worldview (book cover)

Bernardo Kastrup is the executive director of Essentia Foundation. His work has been leading the modern renaissance of metaphysical idealism, the notion that reality is essentially mental. He has a Ph.D. in philosophy (ontology, philosophy of mind) and another Ph.D. in computer engineering (reconfigurable computing, artificial intelligence). As a scientist, Bernardo has worked for the European Organization for Nuclear Research (CERN) and the Philips Research Laboratories (where the ‘Casimir Effect’ of Quantum Field Theory was discovered). Formulated in detail in many academic papers and books, his ideas have been featured on Scientific American, the Institute of Art and Ideas, the Blog of the American Philosophical Association and Big Think, among others. Bernardo’s most recent book is The Idea of the World: A multi-disciplinary argument for the mental nature of reality. He is also the author of Why Materialism Is Baloney: How True Skeptics Know There Is No Death and Fathom Answers to Life, the Universe and Everything. For more information, freely downloadable papers, videos, etc., please visit

Shermer and Kastrup discuss:

  • dualism, monism, panpsychism,
  • material monism, mind monism, and idealism,
  • mind = consciousness?
  • hard problem of consciousness,
  • Why Materialism Is Baloney: How True Skeptics Know There Is No Death and Fathom Answers to Life, the Universe, and Everything,
  • how consciousness could be at the bottom of reality,
  • out of body experiences and near-death experiences (NDEs),
  • In NDE’s, how does the “soul” see and hear?
  • the problem of other minds: how do I know other people are conscious and not zombies?
  • artificial intelligence and consciousness: IBM’s Watson is artificially intelligent enough to win Jeopardy, but does it know it won and beat the GOAT Ken Jennings? Does it even “know” it was playing a game?
  • why science cannot discover the ultimate nature of reality,
  • model dependent realism, philosophy, and science,
  • philosophical zombies and the “other minds problem”,
  • free will, determinism, compatibilism, and panpsychism,
  • objective moral values and science,
  • implications of panpsychism for attitudes toward nature and the meaning of life: “The real question of life after death isn’t whether or not it exists, but even if it does what problem this really solves.” —Ludwig Wittgenstein, Tractatus Logico Philosophicus, 1921,


From You Are the Universe by Deepak Chopra and Menas Kafatos

Consciousness is fundamental and without cause. It is the ground state of existence. As conscious beings, humans cannot experience, measure, or conceive of a reality devoid of consciousness.

From Shermer’s book Heaven’s on Earth response to this assertion

Well, yes, that’s true by definition. You have to be conscious to experience anything, so when Deepak proposes that consciousness and the universe are equivalent, in the sense that it is an “undeniable fact that any universe is only knowable through the human mind’s ability to perceive reality” he is stating the obvious. Call this the Weak Consciousness Principle (WCP): you have to be conscious to experience consciousness. But Deepak goes further than this when he says “if all human knowledge is rooted in consciousness, perhaps we are viewing not the real universe based on limitations of the brain” and “that the apparent evolution of the cosmos since the big bang has been totally dependent upon human consciousness.” That’s reversing the causal arrow, from perception to determination, from being consciously aware of the universe and trying to understand it, to our own consciousness bringing about the universe. Call this the Strong Consciousness Principle (SCP). Which one is right?

From Shermer’s book Heaven’s on Earth on the nature of reality and how we know it

As far as I can tell, the hypothesis that the brain creates consciousness has vastly more evidence for it than the hypothesis that consciousness creates brain. Damage to the fusiform gyrus of the temporal lobe, for example, causes face blindness, and stimulation of this same area causes people to see faces spontaneously. Stroke-caused damage to the visual cortex region called V1 leads to loss of conscious visual perception. Changes in conscious experience can be directly measured by fMRI, EEG, and single-neuron recordings. Neuroscientists can predict human choices from brain scan activity before the subject is even consciously aware of the decisions made. Using brain scans alone, neuroscientists have even been able to reconstruct on a computer screen what someone is seeing. Brain activity = conscious experience. Thousands of lab experiments, in conjunction with naturally occurring experiments in the form of brain tumors, strokes, accidents and injuries, confirm the hypothesis that neurochemical processes produce subjective experiences. Neural activity = qualia. The fact that neuroscientists are not in agreement over which physicalist theory best accounts for mind does not mean that the hypothesis that consciousness creates matter holds equal standing.

From Shermer’s book Heaven’s on Earth on Eben Alexander’s “proof of heaven”

During his NDE he says that his “cortex was completely shut down.” He concludes from this that “there is absolutely no way that I could have experienced even a dim and limited consciousness during my time in the coma,” and therefore “my brain-free consciousness journeyed to another, larger dimension of the universe.” According to Dr. Laura Potter, the attending physician the night he was wheeled into the ER, however, Alexander’s coma was induced by her in order to keep him alive while he was heavily medicated, and that whenever they tried to wake him he thrashed about pulling at his tubes and trying to scream, so his brain was not completely shut down. When Potter later challenged him on this point, Alexander told her his account was “artistic license” and “dramatized, so it may not be exactly how it went, but it’s supposed to be interesting for readers.” In other words, Alexander mashed fact and fiction, meaning that there is really nothing to be explained.

Oliver Sacks on Eben Alexander’s claims:

In a December 2012 article in The Atlantic analyzing Alexander’s claims, Sacks explained that the reason hallucinations seem so real “is that they deploy the very same systems in the brain that actual perceptions do. When one hallucinates voices, the auditory pathways are activated; when one hallucinates a face, the fusiform face area, normally used to perceive and identify faces in the environment, is stimulated.” From these facts the neurologist concluded: “The one most plausible hypothesis in Dr. Alexander’s case, then, is that his NDE occurred not during his coma, but as he was surfacing from the coma and his cortex was returning to full function. It is curious that he does not allow this obvious and natural explanation, but instead insists on a supernatural one.”

The reason people turn to supernatural explanations is that the mind abhors a vacuum of explanation. Because we do not yet have a fully natural explanation for mind and consciousness, people turn to supernatural explanations to fill the void. But what’s more likely? That Alexander’s NDE was a real trip to heaven and all these other hallucinations are the product of neural activity only? Or that all such experiences are mediated by the brain, but to each experiencer they seem real? To me, this is proof of hallucination, not heaven.

From Shermer’s book Heaven’s on Earth on hallucinations of Sam Harris, Oliver Sacks, and Chick D’Arpino

Compare Eben Alexander’s trip with the “trip” taken by the neuroscientist Sam Harris after he and a friend ingested a dose of the drug MDMA, better known as Ecstasy, which he details on the opening pages of his book Waking Up. Harris reports that he was “suddenly struck by the knowledge that I loved my friend.” Not friendship or romantic but “this feeling had ethical implications that suddenly seemed as profound as they now sound pedestrian on the page: I wanted him to be happy.” More than this, Harris says, “came the insight that irrevocably transformed my sense of how good human life could be. I was feeling boundless love for one of my best friends, and I suddenly realized that if a stranger had walked through the door at that moment, he or she would have been fully included in this love.”

Consider hallucinogenic trips taken by the neurologist Oliver Sacks recounted in his autobiography, On the Move. In November of 1965, for example, Dr. Sacks was putting in marathon work weeks and downing huge doses of amphetamines to stay awake, topped off with generous measures of sleep inducing chloral hydrate. One day while dining in a café, as he was stirring his coffee, “it suddenly turned green, then purple.” When Sacks looked up he noticed that the customer at the cash register “had a huge proboscidean head, like an elephant seal.” Shaken by this image Sack ran out of the diner and across the street to a bus, where all the passengers “seemed to have smooth white heads like giant eggs, with huge glittering eyes like the faceted compound eyes of insects.” At that moment the neurologist realized he was hallucinating but that “I could not stop what was happening in my brain, and that I had to maintain at least an external control and not panic or scream or become catatonic, faced by the bug-eyed monsters around me.”

The “love” theme appears to be a common one among NDEs, as well as other anomalous psychological experiences, such as the one I wrote about in The Believing Brain that happened to my friend Chick D’Arpino at four in the morning on February 11, 1966. When he was alone in a bedroom at his sister’s home, feeling despair and loneliness while going through a painful divorce involving the custodial loss of his children, all of a sudden he heard a voice that was neither masculine nor feminine and seemed to him like it was from out of this world. It was so powerful a message that Chick took it upon himself to deliver it to President Lyndon Johnson at the White House, a journey that landed him in a mental institution instead. Although Chick has never told anyone the precise words of the message, or what he thinks the source was, its essence, he told me, was love. “The source not only knows we’re here, but it loves us and we can have a relationship with it.”

Some data from a survey of philosophers discussed in the podcast: 2009 Study of professional philosophers and philosophy grad students:
External world: idealism, skepticism, or non-skeptical realism?
Accept or lean toward: non-skeptical realism 760 / 931 (81.6%)
Other 86 / 931 (9.2%)
Accept or lean toward: skepticism 45 / 931 (4.8%)
Accept or lean toward: idealism 40 / 931 (4.3%)
Mind: physicalism or non-physicalism?
Accept or lean toward: physicalism 526 / 931 (56.5%)
Accept or lean toward: non-physicalism 252 / 931 (27.1%)
Other 153 / 931 (16.4%)
Science: scientific realism or scientific anti-realism?
Accept or lean toward: scientific realism 699 / 931 (75.1%)
Other 124 / 931 (13.3%)
Accept or lean toward: scientific anti-realism 108 / 931 (11.6%)
Free will: compatibilism, libertarianism, or no free will?
Accept or lean toward: compatibilism 550 / 931 (59.1%)
Other 139 / 931 (14.9%)
Accept or lean toward: libertarianism 128 / 931 (13.7%)
Accept or lean toward: no free will 114 / 931 (12.2%)

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This episode was released on August 7, 2021.

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