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Empty old opera gala theater stage and red velvet curtains
Empty old opera gala theater stage and red velvet curtains

How Philosopher John Locke Turned Reality Into Theatre

His “little theater in the mind” concept means that you can’t even know that nature exists. It may just be a movie that’s being played in front of your eyes

Neurosurgeon Michael Egnor did a recent podcast with Arjuna Das at Theology Unleashed, “where Eastern theology meets Western skepticism.”

In this segment, they discuss the way in which theories of perception that began in the early modern era (17thcentury on) led to doubt about our ability to perceive reality.

Here is a partial transcript and notes for the forty-seven to fifty-seven minute mark:

The Cartesian theater of the mind

Arjuna Das: This is one of [the Vedic] arguments against the brain explaining consciousness. By the time it reaches the end stages of its processing, you have about 20 pixels worth of data. So the information that comes from your senses gives you reference points and then your sensors actually are out there in the world connecting with reality… So I guess the information from the senses is also modifying the way in which we perceive. 00:47:12)

John Locke (1632–1704)

Michael Egnor: Sure. It’s a classic debate in philosophy of mind. It goes back really to John Locke: What does perception mean?

Locke argued that what we experience in our minds is our perceptions. And perceptions are essentially pictures of the outside world, that are projected onto our brain in some form. [Philosopher Daniel] Dennett has called this the “Cartesian theater.”

It’s as if there’s a little “us” sitting inside our brains in a little theater, and our eyes are shining movies, and our ears are shining audio, and everything’s coming into this theater …

I think Locke made a terrible mistake. The problem with that way of looking at things is that a completely cuts you off from reality. (00:48:11)

Note: John Locke was concerned with “determining the limits of human understanding in respect to a wide spectrum of topics … what one can legitimately claim to know and what one cannot. ” – Internet Encyclopaedia of Philosophy

Michael Egnor: If you’re living in a theater then you’re utterly dependent upon the projector and the audio system to tell you what’s out there in the world. You have no direct contact with world at all. But if you have no direct contact with the world at all, you can’t communicate with other people, because you can’t be sure that even other people exist, let alone that what you’re hearing from them is what they’re really saying.

You can’t do science because you can’t even know that nature exists. It may just be some movie that’s being played in front of your eyes. So the Lockean way of looking at this as a Cartesian theater, I think, is a serious mistake.

The Aristotelian way is that the form of the object that you’re perceiving actually comes into your mind. That your mind is, in a way, all things. That you connect to the outside world in a direct way. (00:49:13)

Thomas Aquinas (1274–1323)

Saint Thomas emphasized that we don’t see our perceptions. If I’m looking at a tree, what I’m looking at is not my perception of the tree. I’m looking at the tree, the real tree. And my perception is that by which I look at the tree… The end of my perception is the object itself.

And he extended that idea to meaning as well as perception. He said that the meaning of something is not what we understand, it’s that by which we understand… the means by which we encounter the world. (00:50:07)

Note: Thomas Aquinas (1274–1323) was the most famous philosopher of the European Middle Ages. “Combining traditional principles of theology with modern philosophic thought, Saint Thomas Aquinas’s treatises touched upon the questions and struggles of medieval intellectuals, church authorities and everyday people alike. Perhaps this is precisely what marked them as unrivaled in their philosophical influence at the time, and explains why they would continue to serve as a building block for contemporary thought—garnering responses from theologians, philosophers, critics and believers—thereafter.” – Biography.com

Arjuna Das: The whole Cartesian theater thing creates a regress problem too, because, if you’ve got sensory data being presented to the homunculus inside the brain, then what’s going on inside the homunculus? Do you then have another Cartesian theater inside of there? Where does it stop? (00:51:22)

Note: Homunculus “the assumption that there is a little man (or rather, something that is the functional equivalent of a full-fledged visual system, including eyes), or, at the very least, something with inexplicable mental powers, inside the head to reperceive, experience, and interpret the [visual] image.” Stanford Encyclopedia of Philosophy

Michael Egnor: Precisely, precisely. At some point you have to assume a homunculus that is not materialist. So I figured let’s just make the whole thing not materialist. (00:51:42)

An alchemist succeeds in conjuring up a homunculus – 19th-century engraving of Wagner and Homunculus from Goethe’s Faust II

The discussion turned to epistemology

Note: Epistemology: “the philosophical study of the nature, origin, and limits of human knowledge” – Britannica

Michael Egnor: It’s remarkable that the word “epistemology” was coined in the 19th century… Epistemology wasn’t a thing until the 19th century. And their skepticism, derived from Hume and Kant, is, I think, very misguided. It led people to question their senses and their understanding of the world for no good reason.

The way that the scholastic philosophers and the classical philosophers explained knowledge was very straightforward. Our mind grasps the forms of the things in the world. So there’s no problem with explaining how we can know things. The intelligible aspects of things in the world are in our minds. So, that’s how we know.

Epistemology is a brand new problem. And it’s a brand new problem, because we got the philosophy wrong beginning in the 17th and 18th centuries. And we screwed it up so badly, we had to invent a whole new field of philosophy to try to fix the problem that we created in the first place. (00:52:33)

Arjuna Das: I think there’s some truth to that. I do think many problems in philosophy are invented problems. But I do think that epistemology as a discipline of philosophy has merit. In Vedic thought the word they use would be was pramana, which meant proof.

When you boil it down to the simplest, you get three different categories, which is pratyaka, direct sense experience and taka, which is logic. And the third one is testimony. The Sanskrit is shabda pramā which is transcendental sound vibration. So that the highest evidence you can have for something is revealed knowledge. Obviously, most people aren’t going to accept that, but you get the same kind of thing going on in science. (00:53:41)

So what do scientists do? Well, they look empirically at the world. Well, actually a lot of what they do is accept the testimony of other scientists who’ve gone and looked at the world… Our experience can fail because the moon looks like it’s the same size as a coin but actually it’s much larger than a coin. Logic can fail because someone who’s an expert logician can argue any conclusion… So real conclusions come from accepting statements from an authority, from someone who actually knows the truth. When you accept what they say, then you also know. (00:54:29)

Michael Egnor: Yes, but when I show disdain for epistemology, I certainly don’t mean to show disdain for a thoughtful investigation of how we know things and what we know. Certainly that has a long and a very honorable tradition in philosophy.

But it is true that epistomology as a discipline in philosophy really didn’t begin until the 19th century. And so it wasn’t thought of as a separate problem.

And it wasn’t until the skepticism that arose with Hume and with Kant then that people saw a radical problem with knowledge. Knowledge, prior to that, was understood as something to be explored but not something to be doubted. The problem Hume and Kant raised was how can we even have knowledge? And I believe that came from philosophical mistakes. (00:55:12)

Note: Scottish philosopher David Hume (1711–1776) was renowned for his skepticism. German philosopher Immanuel Kant (1724–1804) argued that the structures of the human mind are a distorting influence on our perception of reality.

Arjuna Das: I reckon to solve those persistent logical problems, we just need to make two very simple assumptions. One is that we have an ability to know. So we have a mind and it can access truth if we use it properly. And we have senses and all that.

And two, phenomenological uniqueness or the identity of phenomenology with ontology. What I mean by that is, you can’t have two things which are identical and our experience and perception of them under scrutiny, which are ontologically different. So you have fake leather. You could think it’s real leather but if you scrutinize that you’ll find out, oh, no, this is fake leather. (00:56:18)

Michael Egnor: Yes. There are fascinating ways to look at those issues. I think we were sent down a rabbit hole by the skeptics of the early modern era. But that doesn’t mean that there aren’t some very interesting questions to ask about that, for sure. (00:57:01)

Next: What neuroscience can tell us about the mind and the brain

Here’s a transcript and notes for the first 47 minutes:

How did Descartes come to make such a mess of dualism? Mathematician René Descartes strictly separated mind and matter in a way that left the mind very vulnerable. After Descartes started the idea that only minds have experiences, materialist philosophers dispensed with mind, then puzzled over how matter has experiences.

What’s the best option for understanding the mind and the brain? Theories that attempt to show that the mind does not really exist clearly don’t work and never did. Neurosurgeon Michael Egnor reviews the mind-brain theories for East Meets West: Theology Unleashed. He think dualism makes the best sense of the evidence.

How we can know mental states are real?
Mental states are always “about” something; physical states are not “about” anything. Michael Egnor argues that doing science as a physicalist (a materialist) is like driving a car with the parking brake on; it’s a major impediment to science.

Why neurosurgeon Mike Egnor stopped being a materialist atheist. He found that materialism is just not working out in science. Most propositions in basic science are based on mathematics and mathematics is not a material thing.


How science points to meaning in life. The earliest philosopher of science, Aristotle, pioneered a way of understanding it. Neurosurgeon Michael Egnor talks about the four causes of the events in our world, from the material to the mind.

You may also wish to read: Why the universe itself can’t be the most fundamental thing. Atheist biology professor Jerry Coyne is mistaken in dismissing my observation that proofs of God’s existence follow the same logical structure as any other scientific theory. (Michael Egnor)

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How Philosopher John Locke Turned Reality Into Theatre