I was recently interviewed by Francesco D’Isa for the Italian magazine L’Indiscreto. Here’s the Italian version; below is the English translation:

Why do we feel something? Where does our experience come from? What’s the purpose of consciousness? Could we function without it? These are very difficult questions and not surprisingly consciousness is known as a ‘hard problem’. Well, there’s a theory called Panpsychism that offers an elegant, rational and slightly weird answer: everything is conscious.

The position is held, among others, by Philip Goff, philosopher and consciousness researcher at Durham University (UK). In his very interesting book Galileo’s Error: Foundations for a New Science of Consciousness, Goff reviews the most common answers to the ‘hard problem’ with clarity and depth: dualism, materialism and panpsychism. He clearly favors the last one, but since I had the luck to interview him about his book, I decided to explore all the possibilities with him.

Let’s start with dualism. Goff writes, «According to dualism, reality is made up of two very different kinds of thing: immaterial minds on the one hand and physical things on the other». Then, the hard problem for dualism is that «Dualists have to explain why empirical investigation of the brain shows no trace of mind-brain interaction». The so-called interaction problem is an old one and it was already raised by Princess Elisabeth of Bohemia against Descartes. Over time it became more complex, but the issues remains. As he writes,

«Imagine an immaterial mind were impacting on the brain every second of waking life, by initiating physical processes that caused limbs to move in accordance with the wishes of the conscious mind. When the mind wants to raise the right arm of the body, for example, it causes a change in the brain that will begin a causal process resulting in the raising of the arm. Each event that is directly caused by an immaterial mind will lack a physical cause. In this sense, each impact the mind has on the brain will be an anomalous event, a little miracle.»

We know that for some specific neural activity there corresponds a behavior: let’s say that some neurons fires and I raise my left arm. Why should I suppose another link in the causal chain, like a mind that command the neurons to make my arm raise? Arguments like these put dualism in a very difficult position.

FD: Now, pretending to be dualist, could I argue for a different chain: neurons causes both 1) the rising arm 2) the feeling of it. This way a dualist wouln’t solve the correlation problem, but could maybe make her position easier… what do you think about this possibility?

PG: That’s an interesting proposal. In fact, there’s a name for that view: epiphenomenalism. It’s the view David Chalmers used to defend, and others still do. The problem is that it means that consciousness doesn’t do anything, that it has no impact on the physical world. My pain doesn’t cause me to tell you I’m hurting; my conscious thoughts don’t cause my words. Here’s a ways of bringing out how strange epiphenomenalism is: I’ve just written a book about consciousness. If epiphenomenalism is true, my consciousness had no role to play in shaping my thoughts and my writings about consciousness. It could turn out to be true, but it would be better if we could find a way of allowing one’s consciousness to play a role in determining one’s behaviour.

FD: Then we have materialism. «For the materialist, the inner subjective world of experience is to be explained in terms of the chemistry of the brain, in something like the way the wetness of water is explained in terms of its molecular structure». You subject this thesis to an harsh criticism, founded on the idea that materialists have the theoretical obligation to explain how subjective qualities could be accounted for in terms of objective quantities. As the famous thought experiment of Mary points out, it’s hard to accept that I know everything about a state of consciousness – let’s say pain – just with a perfect knowledge of how it works, without having ever felt it. Moreover, as you write, a ‘philosophical zombie’ who looks and behave exactly like us without having any subjective feelings is logically possible – some joke that Daniel Dennett is one of these zombies. Is it your opinion that complete materialist knowledge of pain should be painful? And why do you think so many thinkers are unable to abandon this point of view about consciousness, despite its problems?

PG: The claim of the Mary thought experiment is not that complete knowledge of pain ought to be painful (that’s a nice way of putting it!). Rather, the idea is that if materialism is true, you should be able to have complete knowledge of pain without actually feeling pain, just from studying the relevant neuroscience. Physical information is all the information, if materialism is true. The problem is we do gain new knowledge when we feel pain: we learn what pain feels like, we gain knowledge about the character of the experience. This is information that neuroscience can never convey. And if there’s information that neuroscience can never convey, then materialism is false.

I think we’re currently going through a phase of history when people are understandably blown away by the great success of physical science, and the extraordinary technology it has produced. This leads people to think that the story we get from physcial science is a complete story of the universe. The irony is that physical science has been so successful precisely because it was never intended to be a complete story of the universe. It has always been focused on a quite narrow, limited task: roughly producing mathematical models to predict the behaviour of matter. Explaining the subjective qualities of experience is a quite different explanatory project.

FD: Let’s finally talk about panpsychism, «the view that consciousness is a fundamental and ubiquitous feature of physical reality». Panpsychists,

 «…believe that the fundamental constituents of the physical world are conscious, but they need not believe that every random arrangement of conscious particles results in something that is conscious in its own right. Most panpsychists will deny that your socks are conscious, while asserting that they are ultimately composed of things that are conscious. Secondly, and perhaps more importantly, panpsychists do not believe that consciousness like ours is everywhere. The complex thoughts and emotions enjoyed by human beings are the result of millions of years of evolution by natural selection, and it is clear that nothing of this kind is had by individual particles. If electrons have experience, then it is of some unimaginably simple form.»

FD: Despite its weirdness, Panpsychism is an elegant and rational solution that avoid all the problems of dualism and materialism. Why should we think that humans (or animals) have the monopoly of consciousness? You discuss evidence of consciousness that there is also consciousness in plants  – and point out that our philosophical arrogance has always turned out to be wrong in the past. The first question that comes to my mind is not around animals or plants, but about the more alien consciousness out there. What does it feel like to be a rock, an atom or a quark? Do spacetime or magnetic fields have consciousness as well?

PG: Most panpsychists will deny that rocks are conscious. The claim is not that everything is conscious, but that everything is made up of things that are conscious. So the rock is not conscious, but perhaps it’s made up of fundamental particles, such as electrons and quarks, that are conscious. Will we ever know what it’s like to be a quark? I think we can know something about the structure of a quark’s experience, as this will correspond to the very simple structure of a quark. I’m not sure we’ll ever fully understand what it’s like to be a quark, as I don’t think we can adopt the perspective of something with so simple a mental life. But that’s a general problem with studying consciousness. As the philosopher Thomas Nagel pointed out, no matter how much we learn about the physiology of bats, we’ll never fully understand what it’s like to be a bat, because we can’t adopt the perspective of a creature that echolocates its way around the world. Our knowledge of the consciousness of others will always be limited by our own limited viewpoint on the world.

Do fields and spacetime have consciousness? Actually, quantum field theory tells us that the fundamental constituents of reality are not tiny particles but universe-wide fields. Particles are then understood as excitations in these fields. If we combine panpsychism with quantum field theory, then we get cosmopsychism. This is the view that the fundamental forms of consciousness are universe-wide fields, and the fundamental conscious mind is the bearer of these fields: the universe itself.

FD: Even panpsychism has its problems, and you dedicate a big part of your book to the biggest of them: the ‘combination problem’:

«How do you get from little conscious things, like fundamental particles, to big conscious things, like human brains? We understand how bricks make up a wall, or mechanical parts make up a functioning car engine. But we are at a loss to understand how little minds could somehow combine to make up a big mind».

Your answers can’t be summarized easily, but what in your opinion the strongest response to the combination problem?

PG: It’s a very serious challenge. One easy way of solving it is by postulating basic principles of nature to bridge the gap. So it might just be a basic law of nature that when you have conscious particles arranged in such and such a way, a consciousness corresponding to the whole system emerges. The problem then, however, is that we don’t seem to see signs in neuroscience of these new forms of consciousness popping into existence. In other words, we’re back to the problems of dualism. I’m currently developing a theory according to which there are basic principles of nature which bring into existence new conscious minds, but those new conscious minds inherit experiences which already exist at the level of fundamental physics. My hope is that, if it’s designed in the right way, it can be entirely compatible with the findings of neuroscience.

FD: This is my biggest doubt: I don’t understand when (and if) conscious minds overlap and when one erases the other. In the split-brain example – people who develop two different personalities once their brain’s hemispheres can’t communicate due to the corpus callosum at the centre of the brain being severed, to treat severe epilepsy. – it would seem that one consciousness is substituted by two new ones. But let’s take the example of a tapeworm: this worm probably has a rudimentary consciousness, but once I get it in my intestine it affects my own consciousness, since I get hungrier, I feel pain, I change some habits… in a way, a parasite is a part of my mind, similar to how hormones affect my consciousness. So, do different conscious minds erase each other, or are there a lot of intersections and sub-sets?

PG: It’s a very interesting question and I think different panpsychists would respond in different ways. Many panpsychists do believe there are many differences conscious minds in your body, and perhaps the split brain case is evidence of that. It could be that there is a consciousness associated with your liver, but we don’t think of it as your consciousness, because it has nothing to do with your thoughts and the words that come out of your mouth. But we also shouldn’t underestimate the role sub-conscious cognitive processes play in a person’s psychology, and it could be that some of the phenomena you point to can be explained in that way. How can a panpsychist make sense of the sub-conscious? The brain processes constituting your sub-conscious mental life will be made up of conscious particles, but it doesn’t follow that the brain processes themselves are conscious.

FD: I find interesting how you link mysticism and panpsychism in the fifth chapter. If we take the mystics’ insight as informative about reality, if panpsychism is correct and if there’s some truth in perennial philosophy (a perspective that views all of the world’s religious traditions as sharing a single, metaphysical truth), maybe mystics experience a ‘formless consciousness’, as you put it, something that might turn out to be «the intrinsic nature of spacetime itself, in a way that is not localized but equally present at all regions of spacetime». I wonder if in the panpsychist frame even rocks, atoms and quarks experience ‘formless consciousness’… are all  things illuminated?

PG: Sometimes mystics do claim to experience a spiritual light shining through all of nature. William Blake talked about a world where every particle of dust breathes forth its joy, as the novelist Philip Pullman pointed out to me in our public discussion. I’m still not sure about the rocks. I guess I think a rock isn’t a really a ‘thing’; it’s just a random collection of particles that we think of as a ‘thing’. But if we’re thinking of universe-wide fields of consciousness, then certainly consciousness pervades the whole of reality in a very literal sense. Perhaps mystics just have a deeper insight into the nature of all-pervasive consciousness than the average person. I’ll keep on mediating and maybe one day I’ll find out!