Philosopher Wilfrid Sellars had a term for the world as it appears, the “manifest image.” This is the world as we perceive it. In it, an apple is an apple, something red or green with a certain shape, a range of sizes, a thing that we can eat, or throw.
The manifest image can be contrasted with the scientific image of the world. Where the manifest image has colors, the scientific one has electromagnetic radiation of certain wavelengths. Where the manifest image has solid objects, like apples, the scientific image has mostly empty space, with clusters of elementary particles, held together in configurations due to a small number of fundamental interactions.
The scientific image is often radically different from the manifest image, although how different it is depends on what level of organization is being examined. For many purposes, including scientific ones, the manifest image, which is itself a predictive theory of the world at a certain level or organization, works just fine. For example, an ethologist, someone who studies animal behavior, can generally do so without having to concern themselves about quantum fields and their interactions.
But if the manifest image of the world is how it appears to us, how do we develop the scientific ones? After all, we only ever have access to our own subjective experience. We never get direct access to anything else.
The answer is that we start with those conscious experiences, sensory experiences of the world, and we work to develop models, theories, of how those experiences relate to each other. (We sometimes forget that “empiricism” is just another word for “experience.” One comes from Greek, the other Latin.) We judge these theories by how accurately they’re able to predict future experiences. It’s the only real measure of a theory, or any kind of knowledge, we ever get.
But often developing these theories, these models, requires that we posit aspects of reality that we can’t perceive. For example, no one has ever seen an electron. We take electrons to exist because they’re crucial to many theories. But they’re most definitely not part of the manifest image.
So the theories give us a radically different picture of the world from what we perceive. Often those theories force us to conclude that our senses, our actual conscious experience, isn’t showing us reality. The only reason we take such theories seriously, and give them precedence over our direct sensory experience, is because they accurately predict future conscious experiences.
Of course, there are serious issues with many of these theories. Two of the most successful, quantum mechanics and general relativity, aren’t compatible with each other. And there’s the measurement problem in quantum mechanics, the fact that everything we observe tells us that there is a quantum wave, until we measure it, then everything tells us there’s just a localized particle.
These are truly hard problems, and solving them is forcing scientists to consider theories that posit a reality even more removed from the manifest image. It’s why we get things like brane theory, the many worlds interpretation of quantum physics, or the mathematical universe hypothesis. If any of these models are true, than the ultimate nature of reality is utterly different from the manifest image.
But as stark as the distinctions between the manifest and scientific images are or could be, it’s not enough for some. Donald Hoffman is a psychologist and philosopher whose views I’ve discussed before. Hoffman has a new book that he’s promoting, and it’s putting his views back into the public square. This week I listened to a podcast interview he did with Michael Shermer.
Hoffman’s main point is that evolution doesn’t prepare us to accurately perceive reality. That reality therefore can be very different than what our perceptions tell us. But Hoffman is going much further than the typical manifest / scientific image distinction. He contends that there isn’t even a physical reality out there. There are only minds. Our perception of reality is a “user interface” that enables access to something utterly alien in nature. Even the various scientific images don’t reflect reality. These are just more user interfaces.
What then is the ultimate reality? Hoffman appears to believe it’s consciousness all the way down. In my last post on Hoffman, I labeled him an idealist, in the sense of thinking that the primary reality is mental rather than physical, and I still think that’s the right description.
Although in the Shermer interview, he says he does think there is an objective reality. Based on what I’ve heard, he sees this objective reality existing because there’s a universal mind of some sort outside of our minds thinking about it, a view that seems similar to the subjective idealism (and theology) of George Berkeley, where objective things exist because God is thinking about them.
How does Hoffman reach this conclusion? He starts with the fact that natural selection doesn’t seem to favor an accurate perception of reality, just an effectively adaptive one. He tests this using mathematical simulations which reportedly tell him that there’s zero probability of natural selection selecting for accuracy.
Here we come to my issues with this idea. Hoffman is using an empirical theory (natural selection) along with empirically observed results of simulations, to conclude that empirical observations aren’t telling us about reality. But if all of reality is an illusion, then how can he trust his own observations? In the interview, he assures Shermer that he avoids this undercutting trap, but if so, it doesn’t seem evident to me.
The second issue is that Hoffman is taking this insight and apparently making a major logical leap to conclude that it leads to much more than the manifest vs scientific image distinction. The established scientific images exist because they’re part of predictive models. Extending these images to another level requires additional models and evidence, and those models must explain the successes of the previous ones. Hoffman owns up to this requirement, but admits it hasn’t been met yet.
My third issue is that Hoffman’s stated motivation for positing this idealism is to solve the hard problem of consciousness. Per the hard problem, there’s no way to relate physics to consciousness, so maybe the solution is to do away with all physics.
But there is an easier solution to the hard problem, one that doesn’t require radically overturning our view of reality. That solution is to recognize what many psychological studies tell us, that introspection is unreliable, including our introspection of experience.
This too is a sharp distinction between the manifest image and the scientific view. The problem, of course, it’s that this version isn’t emotionally comforting. Like Copernicanism, natural selection, relativity, and quantum physics, it takes us ever further from any central role in reality.
Which brings me to my fourth issue with Hoffman’s view. It’s a radical view that’s emotionally comforting, seemingly positing that it’s all about us after all. Of course, just because it’s comforting doesn’t mean it’s wrong, but it does mean we need to be more on guard than usual against fooling ourselves.
I’m a scientific instrumentalist. While I generally think our scientific theories are telling us about reality, I think to “tell us about reality” is to be a useful prediction instrument. They are one and the same. There is no understanding of reality which is not such an instrument.
We can’t rule out idealism. We can only note that any feasible version of it has to meet all the predictive successes of physicalism. Once it does, it has to then justify any additional assumptions it makes. It’s not clear to me that we then have anything other than physicalism by another name, or perhaps a type of neutral monism that amounts to the same thing.
But maybe I’m missing something?