Right now you have a movie playing in your head. It’s an incredible movie with multiple pieces. It’s three-dimensional, with multi-channel sound for whatever you see and hear at this moment, but that’s just the beginning. Your movie has smell, taste, and touch. It has a sense of your body, pain, hunger, orgasms. It has feelings, anger, and joy. It has memories, like scenes from your childhood playing out in front of you. It has that continuous voice narrating at the frequency of your consciousness. At the heart of this movie, you are the one experiencing all this directly. This movie is your consciousness, the object of the mind’s experience of itself and the world.
Consciousness is one of the fundamental principles of human existence. Each one of us has consciousness. We all have our inner movie. There is nothing more direct than this. I certainly know directly about my own consciousness. I cannot be sure that the same applies to you.
Consciousness is what makes life worth living. If we didn’t have consciousness, nothing in our lives would have meaning or value. But at the same time, it is the most mysterious phenomenon in the universe. Why do we have consciousness? Why do we have inner movies? Why aren’t we simply robots processing all this data, producing the result, without experiencing any inner movies at all? At this moment, no one knows the answers to these questions. I propose that in order to integrate consciousness into science, some radical ideas will be needed.
Some say that the science of consciousness is impossible. Science, by its nature, is objective. Consciousness, by its nature, is subjective. So there can never be a science of consciousness. For a long time, and throughout the 20th century, this view prevailed. Psychologists studied behavior objectively, neurologists studied the brain objectively, and nobody ever referred to consciousness. Even thirty years ago, when TED began, there was very little scientific work on consciousness.
About twenty years later, this has started to change. Neurologists like Francis Crick and physicists like Roger Penrose said that now is the time for science to attack consciousness. Since then, there has been a real explosion of scientific work on consciousness. This work is incredible. It is excellent. But it has some basic limitations so far.
In recent years, the crown jewel of consciousness science has been research into correlation—correlation between specific regions of the brain and specific states of consciousness. We saw something related to this from Nancy Kanwisher in the excellent work she presented earlier. We now understand much better, for example, which parts of the brain are associated with the conscious experience of seeing faces, feeling pain, or experiencing happiness. But this remains correlational science. It is not science of explanation. We know that these parts of the brain are related to specific kinds of conscious experience, but we don’t know why. I mention this by saying that this kind of work from neuroscience answers some of the questions we have about consciousness—the question of what specific brain regions do and what they correlate with. But, to some extent, these are the easy problems.
I am not attacking neurologists. Consciousness is not an easy problem. But the real mystery at the heart of this issue is not being touched: Why should all these activities in the brain be accompanied by consciousness? Why is there this inner personal movie? So far we have no clue.
You might say, “let’s give neuroscience a few years. It will eventually turn out to be another emergent phenomenon, like traffic, hurricanes, and life, and we’ll figure it out.” Classic cases of emergence are all cases that arise from emergent behavior 1—how traffic behaves, how a hurricane functions, how a living organism reproduces, adapts, and metabolizes—questions about objective functioning. We could apply this to the human brain to explain behaviors and functions of the human brain as emergent phenomena: how we walk, how we speak, how we play chess—questions related to behavior. But when it comes to consciousness, questions about behavior belong to the easy problems. When the hard problem comes up, the question is, “why is all this behavior accompanied by personal experience?” And here, the basic emergence model, even the basic model of neuroscience, doesn’t have much to say—at least not yet.
I am a scientific materialist. I want a scientific theory of consciousness that works, and for a long time, I wracked my brain looking for a theory of consciousness in purely physical terms that would work. But eventually I realized it couldn’t be done for systematic reasons. It’s a big story, but the basic idea is that what we get from simplified explanations in physical terms, in terms of the brain, are stories about how a system functions, its structure, its dynamics, the behavior it produces—great for solving easy problems, like how we behave, how we function.
But what about personal experience? Why does all this feel like something from the inside? That’s something essentially new, and it’s always one more question. I think we’re at an impasse here. We have this incredible, wonderful chain of explanations—we’re used to it—where physics explains chemistry, chemistry explains biology, biology explains parts of psychology. But consciousness doesn’t seem to fit into this picture. On one hand, it’s a given that we have consciousness. On the other hand, we don’t know how to fit it into our scientific view of the world. I think consciousness right now is a kind of anomaly, something that needs to be integrated into our view of the world, but we still don’t see how. Faced with such an anomaly, we may need revolutionary ideas, and I believe we may need one or two ideas that might seem crazy before we can understand consciousness scientifically.
There are some crazy candidate ideas. My friend Dan Dennett, who is here today, has one. His crazy idea is that there is no hard problem with consciousness at all. The whole idea of the inner personal movie involves some kind of illusion or confusion. We just need to explain the objective functions, the brain’s behaviors, and then we have explained everything that needs explaining. We should give Dennett more credit. This is the kind of radical idea we need to explore if we want a simplified brain-based theory of consciousness. However, for many of us, this view comes dangerously close to entirely dismissing consciousness in a way that is unsatisfying. So I’ll change direction. In the time remaining, I want to explore two crazy ideas that I think are very promising.
The first crazy idea is that consciousness is a fundamental principle. Physicists often accept certain elements of the universe as fundamental principles: space, time, and mass. They build fundamental laws around them, such as the law of gravity or quantum mechanics. These basic properties and laws are not explained by anything more fundamental. On the contrary, they are considered given, and the world is built from there onward.
Sometimes the list of fundamental principles is expanded. In the 19th century, Maxwell discovered that you cannot explain the electromagnetic phenomenon with the existing fundamental principles—the space, time, mass, Newton’s laws—so he proposed fundamental laws of electromagnetism and suggested the electric field as a basic element governed by these laws.
I believe we are facing a similar situation to the case of consciousness. If we cannot explain consciousness with the existing fundamental principles, space, time, mass, charge, then according to logic we need to expand the list. The first thing we need to do is to consider consciousness itself as something fundamental, a fundamental building block of nature. It doesn’t mean we can’t examine it scientifically. On the contrary, something like this opens the way for us to examine it scientifically. Then we need to study the fundamental laws that govern consciousness, the laws that connect consciousness with other fundamental principles: space, time, mass, with physical processes. Physicists sometimes say that we want fundamental laws so simple that we can write them on t-shirts. Well, I believe we face something similar with consciousness. We want to find fundamental laws so simple that they can be written on t-shirts. We don’t know yet what these laws are, but that’s what we’re pursuing.
The second crazy idea is that consciousness might be universal. Every system might have consciousness to some degree. This view is called panpsychism: “pan” for all, “psychism” for mind, every system has consciousness, not just humans, dogs, mice, flies, even Rob Knight’s microbes, or basic particles. Even a photon has some degree of consciousness. The idea is not that photons are smart or that they think. We’re not saying that a photon is anxious because it thinks, “wow, I’m always running near the speed of light. I never get to stop and smell the roses?”. No. But the thought is that photons might have some trace of raw, subjective feeling, some simple precursor to consciousness.
This might sound a little crazy to you. Why would someone think of something so crazy? Some motivation comes from the first crazy idea, that consciousness is a fundamental principle. If it is a fundamental principle, like space and time and mass, it is natural to believe that perhaps it is also universal, in the way that the rest are. It is also worth noting that although the idea seems unreasonable to us, it is less unreasonable to people from other cultures, where the human mind is treated more as a continuation of nature.
A deeper motive arises from the idea that perhaps the simplest and most powerful way to find fundamental laws connecting consciousness with physical function is to connect consciousness with information. Whenever there is information processing, there is consciousness. If there is complex information processing, such as in a human being, then there is complex consciousness. In simple information processing, simple consciousness.
Something very exciting in recent years is that a neuroscientist, Giulio Tononi, took this theory and developed it with a rigorous mathematical framework. He introduced a mathematical measure of information integration called Φ (Phi), which quantifies the amount of information integrated within a system. He proposes that Φ correlates with consciousness. Thus, in a human brain where a large amount of information is integrated, we have high Φ, and therefore a high level of consciousness. In a mouse, with a moderate level of information integration, consciousness is also considered significant, implying a considerable level of Φ. But as we move toward simpler organisms like worms, microbes, or particles, the value of Φ decreases. The amount of integrated information declines but remains non-zero. In Tononi’s theory, this means that even these simple entities possess a non-zero level of consciousness. Therefore, he proposes a fundamental law of consciousness: High Φ equals high consciousness. I don’t know if this theory is correct, but it might currently be the leading theory in consciousness science, and it is being used to integrate a broad range of scientific data. Moreover, it has the appealing quality of simplicity—so much so that you could print it on a T-shirt.
Another final motivation is that panpsychism might help us integrate consciousness into the natural world. Scientists and philosophers have often noted that physics is oddly theoretical. It describes the structure of reality using a bunch of equations, but it doesn’t tell us about the reality underlying them. As Stephen Hawking put it, “what breathes fire into the equations?” On the panpsychist view, we leave the equations of physics as they are, and consider that they describe the flow of consciousness. This is, after all, what physics does: it describes the flow of consciousness. On this view, consciousness breathes fire into the equations. On this view, consciousness does not hover outside the physical world as something additional. It is in the right place, just like the heart.
This theory, I believe, the theory of panpsychism, has the potential to change our relationship with nature, and perhaps it also has some important social and moral implications. Some of these might be unreasonable. I used to believe that I couldn’t eat anything that has consciousness, so I should be a vegetarian. If you are a panpsychist and take this theory literally, you will starve. So I believe that this can change our views, since whatever touches moral purposes and ethical thoughts, does not concern so much consciousness itself, but rather the degree and complexity of consciousness.
It is natural to ask about consciousness in other systems, such as computers. What about the artificial intelligence of Samantha in the movie “Her”; 2 Does she have consciousness? If we approach her with the theory of panpsychism, Samantha performs complex information processing and integration, so the answer is most likely yes, she has consciousness. If this is true, some serious ethical issues arise regarding the ethics of developing smart computational systems and the ethics of deleting them.
In the end, you might ask about the consciousness of entire groups, of the planet. Does Canada have its own consciousness? Or even at a local level, a group, such as the TED conference audience, do we currently have a collective TED consciousness, an inner movie for this TED group, separate from the inner movies of each of us? I don’t know the answer to this question, but I believe it’s something worth taking seriously.
Thus, the panpsychist’s vision is groundbreaking, but I don’t know if it’s correct. I’m much more confident in the first radical idea—that consciousness is fundamental—than in the second, that it is universal. This view raises questions and challenges, such as how this minimal consciousness adds up to the complex consciousness we know and love. If there are answers, we will progress in our search for a more serious theory of consciousness. If not, since this is perhaps the hardest problem in science and philosophy, we can’t expect to solve it overnight. But I believe that in the end we will crack it. Understanding consciousness, I think, is the key to understanding the universe and ourselves. Perhaps it takes the right radical idea.
Thank you.
[ David John Chalmers ]
Translation: Ziggy Stardust
part of the tribute: neuroengineering: the gears of mechanical consciousness
cyborg #15 – 6/2019
- “Emergent behavior” in systems refers to the appearance of increasing complexity originating from simpler states. It is a term used uniformly for both natural animal phenomena (e.g., the behavior of a flock of birds) and for the “self-organization” of robotic systems. ↩︎
- Her: a 2013 science fiction film (;) directed by Spike Jonze. A digital artificial intelligence “assistant” (similar to those already available on the market: Alexa, Siri) but of a much higher level, who enchants the protagonist solely with her voice and “company”… ↩︎