The Interface Theory of Perception and Why Reality is Not What it Seems

Despite centuries of unrelenting scientific progress, the problem of consciousness remains unsolved. How subjective experience can arise from the electrochemical irritation of nervous tissue remains one of the deepest mysteries of the universe.

But according to Donald Hoffman, we have yet to solve the problem of consciousness—not because we lack data or the intellectual capacity—but because our conception of reality is entirely wrong. Once we come to grips with the true nature of reality, the problem of consciousness can be solved.

The first thing to note is that, while this book may entirely transform the way you see reality, the ideas are not new. Hoffman’s “Interface Theory of Perception” is in many ways a re-statement—supported by research in cognitive science—of Imannuel Kant’s transcendental idealism (Hoffman does give appropriate credit to Kant). In the Critique of Pure Reason, Kant claimed to have achieved a “Copernican revolution” in thought by inverting the traditional relationship between subject and object.

According to Kant, objects in the world (things-in-themselves) provide the sense data that the mind uses to construct its perceptions and ideas of those objects in pre-configured ways. However, the ideas of the objects are not the objects themselves, and since we can only experience the world through our perceptions and ideas, we can never get outside of our own minds to discover the true nature of those objects. Our minds are not passive observers of an external reality but are actively involved in the construction of our own reality.

Hoffman is essentially claiming that the latest research in cognitive science and perception—and even in quantum physics—vindicates Kant. Hoffman, of course, provides details from cognitive science that Kant could not have had access to, but the larger point remains the same—that what we perceive is a construction of the mind and that objective reality, which must exist for the mind to perceive anything at all, is fundamentally different from what we directly perceive. Hoffman introduces the evolutionary concept of “Fitness Beats Truth” to show that evolution almost certainly sculpted our minds for fitness, not to accurately represent reality, thus creating the mismatch between “things-in-themselves” and our perceptions of them.

Hoffman uses the analogy of a computer desktop. Our computer files may be represented by icons that occupy space and take certain shapes and colors, but the files themselves do not sit in the middle of our screens or have any shape or color. The files are, at bottom, bits of information and electrical currents in our computer’s memory; the icons allow us to work with the files in an intuitive way but do not represent the underlying reality of the file.

In the same way, consciousness is a three-dimensional virtual desktop that allows us to interact with the world in useful ways but does not accurately represent the underlying reality, whatever that reality is. Hoffman uses convincing examples throughout the book to demonstrate that things like color are not inherent in objects themselves but are active constructions by the mind in response to certain wavelengths of light. In an interesting case study, Hoffman shows us that if the area of the brain that processes colors is damaged, color can disappear entirely from conscious awareness.

The implications of this—if Hoffman (and Kant) is right—are huge. It means that all natural science is essentially reduced to psychology. A deeper understanding of the material world—including both macro-level objects (including brains and neurons) and quantum particles—are simply icons and pixels in the interface of our consciousness. They tell us nothing about objective reality, only about our interface.

Here’s another way to think about it: an expert Minecraft player that is very good at manipulating and controlling the Minecraft world remains entirely ignorant of the underlying computer code and hardware running the game. Likewise, scientists may have expert knowledge of our virtual interface of the world, but, like the Minecraft player, they have no access to the underlying reality that makes the world of conscious perception possible. This inversion of subject and object also explains why quantum experiments are so dependent and influenced by observation—quantum particles are not the deepest components of objective reality, they are the pixels of our conscious interface that the mind creates.

Kant would agree with all of this, but Hoffman wants to go further than Kant. Kant would see the Interface Theory of Perception as defining the limits of human understanding, in that we simply can’t transcend the limits of perception to see the ultimate cause of our perceptions. Stated in another way, the fundamental nature of reality is about as discoverable as a new color you’ve never seen.

But Hoffman, for some reason, refuses to accept this. He thinks that the ultimate nature of reality can be discovered scientifically and that it is essentially composed of conscious agents. According to Hoffman, we have yet to solve the mystery of consciousness—not because we’re awaiting new scientific discoveries or have reached the limit of human understanding—but because our entire conception of reality is wrong. Once we understand that the world is composed of conscious agents that ultimately create spacetime and all the objects contained within it, we can finally solve the hard problem of consciousness.

I’ll admit that I found this argument to be less persuasive. I think that Hoffman has discovered, like Kant, the boundaries and limits of human understanding. We can investigate the world scientifically as its presented to us, but we have no conceivable way to transcend the limits of our own virtual conscious interface. The things-in-themselves, the objective reality that must exist to provide sense data to our minds, cannot be investigated directly because whatever data we acquire will always be filtered through perceptual systems that we can’t control or transcend. It’s like being born blind and trying to understand what it’s like to see color.

Some readers may be persuaded by Hoffman’s argument, but I don’t see a way around this. If perception is created by the mind based on an objective reality that is different, then we simply have no way to access to this objective reality. It’s what Wittgenstein meant when he said that what can be said can be said clearly, and “whereof one cannot speak, thereof one must be silent.” We can speak about our conscious interface (science and human behavior and experience), but when we attempt to transcend the interface the result is always nonsense. As Kant said long ago, this is precisely the point where we’ve reached the limit of human understanding. Hoffman thinks otherwise; who is ultimately right the reader is left to decide.

The Case Against Reality is available on