Conscience and Consciousness

As a philosopher, I like to use thought experiments. Suppose a BBC newsreader tweeted that there were more and more black families moving into their area and it was really bringing down the tone of the neighbourhood. I don’t know about you, but I’d be outraged. I’d probably want to express my outrage through social media, and I’d enthusiastically sign a petition to get that newsreader sacked from their job. This seems like a totally normal reaction to someone in a position of public responsibility making such an abhorrent statement.

Would that make me part of the ‘woke mob’ intent on destroying free speech that many on the right of politics have been railing against of late? The intro video on the ‘Free Speech Union’ (FSU) website presents the firing of Danny Baker for tweeting an image of a couple with a chimp to accompany the birth of the first mixed race royal baby as an example of suppressing free speech. But was Baker’s tweet any less abhorrent than the tweet of my imagined newsreader? I suspect Toby Young – Secretary General of the FSU – would argue that it is. He’d be free to do so. But those who do find that tweet deeply morally abhorrent are also free to express their view and to lobby for consequences. That’s how free speech works. What is singularly lacking from the FSU is a consistent and principled policy on when moral outrage is and is not warranted.

The right-wing free speech warriors are also pretty inconsistent about real world cases of free speech infringement. There wasn’t much to be heard from these valiant heroes when the General Secretary of the Labour party barred MPs and Labour party members from discussing Jeremy Corbyn’s suspension – a literal ban on free speech. Nor when an outraged mob of 26 MPs and 2 peers took their pitchforks to the National Trust for daring to produce a report on the links between the Trust’s properties and the slave trade. And when the government took the scarily authoritarian step of ordering schools not to use resources from organisations opposed to capitalism? Not a peep. It seems that their concern with free speech is conditional on what is being said.

This blatant lack of consistency was also apparent recently when Deputy Research Director of the Free Speech Union Emma Webb went on Talk Radio to express her support for the decision of the International Olympic Committee to ban athletes from taking the knee. Webb seemed not even to register the tension in a campaigner for free speech advocating the quashing of free expression. I tweeted about this, and actually received a polite response from Webb. For some reason, however, Webb deleted her response to me a short while later. In the absence of someone to talk to on twitter, I decided to write this article instead.

Webb defended her position by saying that her point was that rule 50 – that ‘no kind of demonstration or political, religious or racial propaganda is permitted in any Olympic sites, venues or other areas’ – was being consistently applied, and that what she had said was consistent with thinking that rule 50 should be scrapped. However, what Webb actually said in the interview was that the committee’s action was the ‘right decision’, not merely that it was a consistent application of rule which may or not be a good one. If I said that the Taliban’s decision to stone a particular individual for adultery was ‘the right decision’, it would be reasonable to interpret me as asserting not merely that they were consistently applying a law, but that that law was appropriate. Why would anyone bother to praise the consistent application of a rule they didn’t agree with?

Indeed, Webb went on to defend rule 50, on the basis that 70% of athletes surveyed wanted to keep the rule. Do the FSU decide all of their policies based on surveys of non-members? Wouldn’t it be better to defend a principled stance of their own? Perhaps the Free Speech Union could develop a consistent policy that there should be safe spaces where sensitive souls can be protected from certain kinds of speech. But it would take some work to make that consistent with Toby Young’s attack on a workplace in which football talk was banned from the work environment. It’s all a bit of mess.

If at any point the FSU is interested in formulating a coherent statement on what they stand for, I’d recommend taking some time to reflect on the important distinction between ‘freedom of speech’ and ‘having a platform.’ Most of the so-called infringements of free speech they focus on are actually just instances of people being declined a platform. The fact that I don’t have as many twitter followers as Toby Young doesn’t mean my speech is being curtailed. That’s not to say there aren’t important ethical issues regarding who gets a platform. We surely want a range of views to be aired, and minority voices to be heard. But if that’s really your concern, then you’d make better use of your time focusing on issues of media plurality. You might, for example, be concerned with the fact that there are hardly any trans columnists at our national newspapers. And you would certainly be worried that exploitation of the UK’s antiquated libel laws might be about to destroy the only radical left print magazine left in this country.

It’s not for me to look into the hearts of Young and Webb, to judge whether their motives are pure. But my job is to spot incoherence and inconsistency, and I can see a mile off that the policy platform of the FSU needs a lot of work. I wish them well and would be happy to offer philosophical consultancy at a modest fee. But if they are serious about developing a consistent stand on free speech, then they should be prepared to find themselves in a very different Free Speech Union from the one that exists today.

Our best current science suggests that our universe is fine-tuned for life. That is to say, certain numbers in basic physics – e.g. the strength of gravity, the mass of electrons, etc. – are, against improbable odds, exactly as they need to be for life to be possible. Many scientists and philosophers think this is evidence for a multiverse, but I disagree. What we have evidence for us that our universe is fine-tuned and postulating a huge number of other universes doesn’t explain this.

I recently wrote a Scientific American article on this, and there have been two blog posts from Skeptics Guide to the Universe in response. Earlier this week, host Steve Novella and I got together to discuss the issue, and an edited version of our discussion will be going up on their podcast tomorrow. The discussion prompted me to clarify my argument in my own mind, and I’d like to share here how I’m thinking about it now.

Steve accuses me of committing the lottery fallacy. But what is the lottery fallacy? Suppose against improbable odds my lottery numbers come up. Clearly there’s something going wrong if I think there needs to be some special explanation of the fact that I won. Steve suggests that the error consists in focusing on the particular person who won – Philip Goff – rather than merely the fact that someone won. Similarly, by focusing on the fact that our universe – rather than just some universe – is fine-tuned, he thinks I’m committing the same fallacy.

I don’t think this is the right explanation of the lottery fallacy. Sometimes a focus on the particular person is appropriate. Suppose, for example, that the partner of the person who picked the numbers wins on a billion to one odds. Then it does seem we want to focus on the particular person who won.

What’s the difference between the two cases? The fact that Philip Goff won the lottery is improbable, but it’s not improbable that it happened by chance. Why is that? Because there’s no (non-ad hoc) non-chance hypothesis that would render it much more probable. Whereas when it comes to the fact that the partner of the person who picked the numbers won, this is just as improbable as Philip Goff winning, but in this case it’s not only improbable but improbable that it happened by chance. Why? Because there is a (non-ad hoc) non-chance hypothesis that would render it more probable, namely the hypothesis that there was collusion between the person who chose the numbers and her partner. Assuming that hypothesis, it’s much more likely that the partner would win that it is on the hypothesis that the numbers were picked randomly.

What about the fine-tuning case? I think we’re struck by the fine-tuning not because it’s improbable – whatever numbers had come up would be equally improbable – but because it’s improbable that it happened by chance. And, again, this is because there’s a non-chance hypothesis that would render it much more probable, namely the hypothesis that considerations of value were involved in determining the values of the constants. If the process that determined the constants was sensitive to the value of the resulting universe, then it wouldn’t be surprising that the constants would end up fine-tuned, much less surprising that it would be if they were selected at random.

So I don’t think the lottery fallacy is anything to do with focusing on the particular individual rather than the general fact; rather it’s a matter of fallaciously inferring from the fact that something is improbable to the fact it’s improbable that it happened by chance. But the fact that our universe in fine-tuned is not only improbable, it’s also improbable that it happened by chance. Therefore, focusing on the fact that our universe is fine-tuned – rather than that some universe is fine-tuned – does not commit the lottery fallacy.

So that’s why I don’t agree with Steve’s argument against my position. Let me try a different way of making the case for my position (this is a modified form of the argument White defends in the postscript to a reprint of this article). We can only gain support for a hypothesis with the evidence we in fact have. We can either think of evidence as our actual observations, or as the concrete, physical states of affairs we know about through observation. Whether you think of the fine-tuning evidence as our actual observations, or you think of it as the concrete fine-tuned physical universe we live in, in either case our evidence is not made more probable by the multiverse hypothesis. Yes, the existence of some fine-tuned universe is made more probable by that hypothesis. But we have to work with the evidence we in fact have, and the evidence we in fact have is constituted by the properties of this concrete, physical universe (or our observations of it), and this is not made more probable by the multiverse hypothesis

Many people have worried about the Joker analogy I make in my Scientific American article, on the grounds that, in this thought experiment, you pre-exist the flukey event. In the discussion I had with Steve, I got around this with a different thought experiment. Suppose your conception came about through IVF. And suppose you discover as an adult that when the doctor fertilised the egg, she rolled twenty dice to see whether she’d do it, committing only to fertilise the egg if they all came up sixes. Does your discovery that your birth was dependent on this improbable event provide you with evidence that the doctor did the same in many other IVF cases, rolling dice to decide whether to fertilise the egg? I don’t think so; all you have evidence for is that your conception was decided in this way, and whether or not the doctor did this in other cases has no bearing on how likely it was that the right numbers would come up with your conception. By analogy, all we have evidence for is that the right numbers came up for our universe, and whether or not there are other universes has no bearing on how likely it was that the right numbers came up for our universe.

In correspondence after our discussion, Steve proposed tweaking the thought experiment: suppose I’m considering whether the doctor rolled dice many times or only once to decide whether to fertilise the egg that made me. I agree in that case you would have evidence for that hypothesis, as that hypothesis makes *your* existence more likely, and your existence constitutes your evidence. But that modified IVF hypothesis corresponds to a sci fi scenario in which our universe had a number of shots at fixing its constants (i.e. random processes reset them numerous times) and the Guardian of the Universe only allowed it to proceed if they came up fine-tuned. That hypothesis would make our evidence (our fine-tuned universe) more likely. But that’s not the multiverse hypothesis. According to the standard multiverse hypothesis (eternal inflation + string theory) our universe had only one shot at fixing its constants. That corresponds to a scenario in which there is only one dice roll to determine whether the egg that produced you gets fertilised.  

In our discussion, Steve came up with another thought experiment. Suppose the mischievous god Loki has just brought you into existence, and he tells you that he rolled twenty dice to decide whether or not to create a person, committing only to create a person if they all came up six (I’ve modified the example a little to make it similar to mine, but the substance is the same). Do you have grounds to think Loki has done this many times, on the assumption that each time he creates a person it’s a distinct person? I admit I did have to think about this one, and my intuitions are less firm that in the IVF case. So we need an explanation of why intuitions are different in these two cases. I suggest it’s because in the IVF case, it’s totally clear that the hypothesis I’m considering is one in which other babies would be born who aren’t me, whereas in the Loki case, it’s easy to slip into thinking he’s been having lots of shots at creating me. If I’m considering the scenario in which Locki had numerous shots at creating me, then I do find evidential support. But this is analogous to the tweaked IVF thought experiment in which the doctor rolled dice numerous times to decide whether to create me, and, as I argued above, this does not mirror the real-world fine-tuning case.

In summary: the fine-tuning is very puzzling, but it’s not evidence that we live in a multiverse.

Do the laws of physics rule out free will? Neuroscientist Kevin Mitchell has a recently argued (paper and blog post):

• If the laws of physics are deterministic, then free will is ruled out
• If the laws of physics are indeterministic, then this makes room for the reality of free will.

It’s a really interesting paper but I have some disagreements, which I would like to outline here.

A quick preliminary remark: there is a huge debate in philosophy as to whether or not human freedom is compatible with determinism (we can define determinism as the thesis that the initial state of the universe, in conjunction with the laws of nature, determine everything that will happen subsequently). Compatibilists believe is that free will and determinism can happily co-exist. Mitchell is well aware of this debate, and briefly motivates his commitment to incompatibilism: that view that if the universe is determined, we’re not really free. For the purposes of this blog post I will assume incompatibilism.

Given the assumption of incompatibilism, Mitchell argues that the way to avoid the clash between freedom and indeterminism is to embrace the indeterminism entailed by many interpretations of quantum mechanics. Now, many have pointed out that mere randomness isn’t what we need to make sense of freedom, and Mitchell acknowledges this. But he thinks that the absence of total determinism in fundamental physics provides some ‘causal slack’ that mental processes at the neurophysiological level can then take advantage of:

“The inherent indeterminacy of physical systems means that any given arrangement of atoms in your brain right at this second, will not lead, inevitably, to only one possible specific subsequent state of the brain. Instead, multiple future states are possible, meaning multiple future actions are possible. The outcome is not determined merely by the positions of all the atoms, their lower-order properties of energy, charge, mass, and momentum, and the fundamental forces of physics. What then does determine the next state? What settles the matter?”

Mitchell’s answer this posed question is the agency of the organism: physics leaves certain options open, the organism then decides from among those options.

It sounds intuitive, but I don’t think this strategy ultimately works. Even among indeterministic interpretations of quantum mechanics, although the physics doesn’t conclusively settle what will happen, it does determine the objective probability of what will result from any given physical circumstance. Although we can’t predict with certainty, say, where a given particle will be located when we make a measurement, the Born rule tells us, for any given location in the universe, precisely how likely we are to find the particle in that location. It’s not determinism, but it’s not a ‘free for all.’

Mitchell worries that if the physics determines what I’m going to do, then I’m not really free. But physics determining the objective probability of what I will do is no less constraining. If whether I water Susan (my Madagascan dragon tree) is really up to me – in the strong incompatibilist sense – then surely the physics can’t fix how likely it is that I will water Susan. If it’s just totally up to me, then it could go either way depending on my radically free choice.

Here’s a little thought experiment to make the point clear. Take the moment when I’m about to decide whether or not to water Susan. Let’s say the Born rule determines that there’s a 90% change my particles will be located in the way they would be if I watered Susan and a 10% chance there’ll be located in the way that corresponds to not watering Susan (obviously this is a ludicrously over-simplistic example, but it serves to make the point). Now imagine someone duplicated me a million times and waited to see what those million physical duplicates would decide to do. The physics tells us that approximately 900,000 of the duplicates will water Susan and approximately 100,000 of them will not. If we ran the experiment many times, each time creating a million more duplicates and waiting for them to decide, the physics tells us we would get roughly the same frequencies each time. But if what happens is totally up to each duplicate – in the radical incompatibilist sense – then there ought to be no such predictable frequency. The number that do and don’t water the plant should change each time, as the radically free choices of each individual varies.

In other word, indeterministic quantum mechanics doesn’t provide the kind of causal slack Mitchell is seeking. The problem is that objective probabilities constrain our choices as much as deterministic laws. After all, a deterministic law is just a law that yields an objective probability of 1 that a given outcome will occur.

All is not lost, however. I think Mitchell is conflating two claims:

• The laws of physics are deterministic
• The universe as a whole is deterministic

How could these come apart? They come apart if the laws of physics are ceteris paribus laws, i.e. laws that tell us what will happen in the absence of other causal influences. On this interpretation of physical law, the probabilities yielded by the Born rule are the objective probability of what will occur in the absence of some other causal influence. Such other causal influences might include the kind of irreducible causal powers Mitchell believes reside at the level of neurobiology. Mitchell seems to be concerned to avoid a violation of the laws of physics. But if the laws of physics are ceteris paribus laws, then higher-level causal powers should be thought of as complementing the laws of physics rather than contradicting them. If physics basically tells us ‘X will happen unless there are some higher-level causal forces,’ and X doesn’t happen precisely because there are higher-level causal forces, then nothing occurs that is inconsistent with physics.

It does not follow that there are no empirical challenges for a proponent of incompatibilist free will. Some philosophers have argued that we have strong empirical grounds for thinking there are no irreducible causal influences of the kind Mitchell believes in, that everything that happens at higher levels can be reduced to the causation we find in physics. But this is an empirical question about neurobiology. My point here is just that the question of whether the laws of physics are deterministic has no bearing on the question of whether the universe as a whole is deterministic, and hence no bearing on the question of whether or not we have free will.

The success of natural science over the last five hundred years has been truly mind-blowing. It doesn’t follow, however, that science is well-suited to answering all questions. Sam Harris has suggested that science can answer the questions of ethics as well as our questions about the nature of reality. But like many, it seems to me that there are many ethical questions which are just not suited to being answered scientifically. There’s no experiment that will tell us whether ethics is ultimately about maximizing good consequences or about fundamental rights and duties.

It is commonly assumed that the task of explaining consciousness is scientific rather than philosophical. I think that’s half right. It’s the job of neuroscience (among other things) to establish the neural correlates of consciousness (NCCs), that is, to work out which physical states of the brain are correlated with which subjective experiences. We have a robust and well-developed experimental approach for answering these questions.

However, establishing the NCC is just one half of a theory of consciousness. We also want to explain those correlation, to work out why certain physical states are correlated with experiences. As things stand, I think this is a philosophical rather than a scientific question. Philosophers have offered a number of different answers to this question. Here are three of them:

• Naturalistic dualism – A subjective experience is a very different kind of thing from a physical brain state, but the two are bound together by natural law. In addition to the laws of physics, there are fundamental psycho-physical laws of nature which ensure that, in certain physical circumstances, certain experiences emerge.
• Materialism – Each subjective experience has a purely physical nature. Having subjective experiences – feeling pain, seeing red – wholly consists in having certain complex patterns of neuronal firing.
• Panpsychism – Each physical state has a purely experiential nature. Physical science tells us what matter does whilst leaving us in the dark about what it is. Having physical states – being negatively charged, being a certain pattern of neural firing – wholly consists in having certain kinds of subjective experience.  

All of these theories are empirically equivalent: there is no experiment that can decide between them. That’s not really a surprise, as this is not a purely empirical question. It’s rather a question of why something that is publicly observable (brain activity) always goes together with something that is not publicly observable (subjective experience). This is isn’t the kind of question an experiment can answer, just as questions about the fundamental character of ethics can’t be answered experimentally.

One option is agnosticism. If we can’t decide between these views experimentally, then maybe we should simply say that we don’t know which is true. Another option is to try to decide between them on the basis of non-experimental considerations. In other words, to do philosophy.

If I don’t think explaining the NCC is a scientific question, why is my book subtitled ‘Foundations for a New Science of Consciousness’? The task of explaining the NCC is currently in the domain of philosophy. But when a broad consensus arises as to how to address a question, philosophy turns in to science. The aim of my book is precisely to develop such a methodology for that bit of the science of consciousness which is currently in the domain of philosophy.  

So is it the job of science or philosophy to explain consciousness? As things stand, the task of accounting for consciousness is partly scientific (establishing NCCs) and partly philosophical (explaining the NCCs). If we one day achieve societal consensus on how to address the latter half of the puzzle, the task of accounting for consciousness will move entirely into the domain of science. I think this is starting to happen, but – just as at the start of the scientific revolution – there needs to be some serious engagement with philosophy before we get there.

The BBC’s recent documentary of ‘The Rise of the Murdoch Dynasty’ is worth watching. However, two important details from the history it conveys were missed out:

1. During 2011, Murdoch was attempting to buy all of BskyB (as reported in the documentary). The then culture secretary Jeremy Hunt was put in charge of assessing ‘on a quasi judicial basis’ whether Murdoch’s plan was compatible with media plurality. In 2012, the Leveson enquiry revealed a lengthy record of emails, texts and phone calls showing a secret communications channel between Hunt and James Murdoch devoted to pushing the deal through and giving Murdoch what he wanted. In one email, Frédéric Michel, James Murdoch’ chief lobbyist, wrote to Murdoch of Hunt ‘He said we would get there in the end and he shared our objectives.’

• When Prime Minister David Cameron was still refusing to speak out against Murdoch, Labour leader Ed Miliband made the decisive intervention of declaring that Murdoch’s empire should be broken up. This was the first time in a long time a leader of a major political party had challenged Murdoch’s power. Without this detail, the audience is left with the impression that both former Labour and Conservative leaders have been equally subservient to Murdoch.

There was also no discussion of how Murdoch is ensuring his grip on UK politics continues in spite of failing newspaper sales through the establishment of talkRadio and Times Radio (Murdoch is also planning to launch a Fox News-style show in UK, although perhaps this was announced after the documentary was made). We are not left with the awareness that this is still going on and is something we can challenge.

I’ll leave to readers to decide whether the BBC is reluctant to criticise a still prominent Conservative MP or to praise of a Labour leader significantly more left wing than Tony Blair.

I’m delighted to announce that there will be a special issue of the Journal of Consciousness Studies on my book Galileo’s Error: Foundations for a New Science of Consciousness, which will be edited by Alex Moran (Oxford University) and myself. The issue will feature short papers (4-6,000 words) on the themes of the book, contributed by leading physicists, neuroscientists, theologians and philosophers, as well as a response piece by me commenting on each of the papers. Publication will probably be in October 2021. Current contributors are:

Carlo Rovelli, Centre de Physique Théorique de Luminy of Aix-Marseille University

Lee Smolin, Perimeter Institute for Theoretical Physics

Christof Koch, Allen Institute

Joanna Leidenhag, St. Andrews

Sara Lane Ritchie, University of Edinburgh

Annika Harris, New York Times bestselling author of CONSCIOUS: A Brief Guide to the Fundamental Mystery of the Mind

Chris Fields, Independent researcher

Alyssa Ney, University of California

Michelle Lui, University of Hertfordshire

Alex Moran, University of Oxford

We have a few other scientists and philosophers tentatively on board time allowing, who I’ll hopefully confirm in due course. Very excited about what looks like it’s going to be a really great, interdisciplinary volume on consciousness!

I have just published a piece in the Institute of Art and Ideas, raising some objections to Bernardo’s Kastrup’s analytic idealism. One aspect of the disagreement between Bernardo and I is whether the following conditional is true: if physicalism is true, conscious states are epiphenomenal (i.e. have no causal effect on the physical world). Bernardo thinks it’s true; I think it’s false. I gave my reasons for thinking this in the IAI piece, but I would also like to counter-respond to some responses Bernardo raised in this blog post. I thought it better not to include this in the IAI piece, as it’s a somewhat peripheral concern. But I would recommend reading the IAI piece before reading the discussion below.

Bernardo argues for the claim <if physicalism is true, conscious states are epiphenomenal> by appealing to the work of David Chalmers on this topic, which is generally taken as canonical. Bernardo said:

“David Chalmers recapitulates the mainstream physicalist argument that, because the physical world is putatively causally-closed, phenomenal states must be physical states. In other words, because they have no causal efficacy, phenomenal states cannot exist as phenomenal states; instead, all the qualities they entail must be reducible to the quantities of physics.”

The first sentence above is correct. The second sentence, however, is not only not a correct interpretation of the first, but it contradicts the first. Again, we’re back to the logic of identity (see the IAI article). If phenomenal states are – are identical with – physical states, it follows – from Leibniz’s law – that, if physical states have causal efficacy, then phenomenal states have causal efficacy. I suspect from what he says elsewhere in the post that Bernardo will think I’m playing academic games. But the laws of logic don’t play games for anyone.

I think Bernardo may be confusing identity with elimination. Some physicalist hold that phenomenal qualities should be eliminated, in which case they don’t have causal efficacy but only because they don’t exist. The more common physicalist position is that conscious states are identical with, or wholly constituted of, physical states, in which case they have causal efficacy because they are identical with/wholly constituted of physical states. Bernardo seems to be trying to get to a middle way option for the physicalist: phenomenal states exist, but they don’t exist ‘as phenomenal states’ because they’ve been ‘reduced’. But what on earth would it mean for a phenomenal state to exist but not to exist as a phenomenal state? When physicalists say that they’ve reduced phenomenal states, they mean that phenomenal states really exist (as phenomenal states, how else would a phenomenal state exist?), but that they’re either identical with or wholly constituted of physical states.

In any case, the mainstream argument for physicalism that Chalmers is discussing claims that if dualism is true, then phenomenal states have no causal efficacy (because the physical world is causally closed), and hence that the only way we can ensure that phenomenal states have causal efficacy is if physicalism is true. I don’t buy that argument as panpsychism also gives us a way of ensuring that phenomenal states have causal efficacy (Chalmers agrees with this, which is one of the main points of the article). But the point is that Bernardo is misunderstanding what the causal closure argument is trying to show. If you don’t believe me, I recommend asking Chalmers, or any other academic philosopher working in this area, on either side of the debate. This is not a point of controversy.

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!

The March edition of Investigación y Ciencia, the Spanish edition of Scientific American, published a translation of my Scientific American article ‘Galileo’s Big Mistake‘. In June it published my answers to a couple of questions from readers. Below is the English translation of the questions and my replies.

First Letter: In “Galileo’s Big Mistake,” Philip Goff argues that, in order to scientifically confront the problem of consciousness, one should overcome Galileo’s scientific viewpoint based on limiting the explanation of the natural world to its quantitative properties. This conclusion is based on the fact that consciousness only manifests itself when the subject confronts the qualitative —not quantitative— properties of natural entities.

However, when considering the natural world from the perspective of a conscious subject, all of it boils down to consciousness, since even the mathematical laws used by Galileo to quantify natural phenomena are nothing but ideal entities: they need a subject who thinks about them, and as such they don’t belong to the realm outside the subject. In fact, if the philosopher George Berkeley was right with his motto “esse est percipi,” nature itself wouldn’t exist in the absence of a conscious subject perceiving it.

In summary, what a subject can know about consciousness will always be limited to their own conscious activity. And it doesn’t seem possible for the empirical science to establish what consciousness is by means of experiments carried out outside consciousness itself, beyond the mere correlations mentioned by the author between the various mental tasks and the neural activity of certain brain regions.
JOSÉ ENRIQUE GARCÍA PASCUA; Torrecaballeros, Segovia (Spain)

My Reply: I certainly agree that all knowledge of mediated through consciousness, and that consciousness is the only thing we know for certain is real. But if I only believe in things I’m utterly certain of the existence of, then I’ll be quickly led to solipsism: the view that my conscious mind is the only thing that exists. We cannot know for certain that other people exist, or, as Bertrand Russell observed, whether the world was created more than five minutes ago. In order to live life, we need to trust our memories, and we need to trust that the people our sensory experiences seem to put us in touch with are real. 

It could be that these other people are non-physical conscious minds, as George Berkeley supposed. But the trouble with Berkeley’s view is that we require some explanation of the commonalities and regularities in our experiences. Why is it that when my wife and I look in the same direction, we both have an experience of a table. Berkeley postulated a constantly intervening God to make sense of this, but this seems to me an extravagant and inelegant postulation. Michael Pelczar and Donald Hoffman try to make sense of this without God, and their work is really interesting. However, it seems to me much more simple and straightforward to postulate a shared physical world to account the commonalities and regularities in our experience. Why do my wife and I both experience a table? Because there’s a table out there in physical reality, and it causes our experiences by impacting on our bodies. 

However, in order to avoid Galileo’s Big Mistake, I adopt a panpsychist, rather than a materialist, conception of physical reality. There is a physical world out there, but it’s infused with consciousness. This is the positive bit of my book ‘Galileo’s Error: Foundations for a new Science of Consciousness.’

Second Letter: The general idea behind Goff’s article stems from the thesis implied by the example of the tree: “When a tree comes crashing down in a forest, the crashing sound isn’t really in the forest, but in the consciousness of an onlooker. No onlooker, no consciousness, no sound.” However, I don’t agree with such viewpoint: the sound produced when the tree crashes doesn’t depend on whether an observer is present or not, since the pressure waves exist anyway, also in the absence of an observer.

In Galileo’s time, the existence of neurons and brain functionalities wasn’t known, and therefore it didn’t make sense to talk about modelling internal perceptions of any kind. But today we have mathematical models that are able to determine the effect of the sound when, in the form of neural pulses, it reaches the various brain regions and activates them in specific ways. Therefore, and at least up to this point, a scientific model based on mathematics would still be valid.

The fact that we are still ignorant about the origin of consciousness doesn’t mean that consciousness cannot be modelled mathematically. It’s true that such a modelling may be impossible, but we won’t know until we learn about the nature of consciousness and try to detect it and measure it.
JOSÉ MEDINA FERRER

My reply: It depends what you mean by ‘sound’. If you mean ‘vibrations in the air’, then, yes, there is sound out there, independent of the observer. But if you mean ‘the qualitative sound we seem to encounter in our experience,’ then I would disagree that this exists out there in the physical world.

Galileo’s contemporaries had crude theories of brain mechanisms. We certainly have a much better understanding of the mechanisms of the brain. But none of this has made the slightest difference with respect to the problem of consciousness. The problem is that physical science, whether the science of Galileo’s time or are own, works with a purely quantitative vocabulary, and you can’t capture the qualities of consciousness in these terms. The language of physical science can’t convey to a colour blind neuroscientist what it’s like to see red. I agree that we can model consciousness in mathematics, and such models are useful. But they abstract away from the qualities involved in consciousness, and hence only tell a partial story. It’s a bit like how mathematical models in economics are very useful, even though they abstract away from the specific details about individuals and their labour. 

I believe we are currently going through a phrase of history in which we are blown away by the success of physical science, and this leads us to think that physical science is the only source of knowledge, that everything else is superstition. The irony is that physical science has been so successful precisely because it was designed to be a partial description of reality, abstracting away from those aspects of reality that can’t be captured in mathematics.  

Happy Easter! I hope people are managing to enjoy some leisure and pleasure in these unique circumstances of lockdown. One thing I did was to watch this video of Daniel Kaufman and Massimo Pigliucci raising some objections to the (very different) views of Keith Frankish and I. I enjoyed this and I’m very grateful to Daniel and Massimo for thinking about my work. I’d like share a couple of quick responses.

My first issue is that they reject my version of panpsychism without really articulating what it is. This is especially striking when they discuss the response I gave to Sabine Hossenfelder’s blog post critiquing panpsychism in my public exchange of letters with Massimo. At 28:29, Massimo says that I respond by saying that ‘panpsychism is not about physical properties as we understand them.’ This is at best a massive oversimplification of my response to Hossenfelder and is arguably misleading. Daniel then goes on to criticise me in very strong terms (including accusing me ‘either unresponsive or obtuse’ on twitter…I thought we’d got on on twitter!) for not appreciating I need to offer an account of how certain properties can be ‘elemental properties of matter but not material’ (he contrasts me to his former supervisor Katz, who wrote ‘a whole book’ articulating a view according to which there are entities with both abstract and concrete properties).

The thing is, I do have an account, which I have written two books (one academic and one popular) defending. And that account is built on upon two further books, one by Bertrand Russell and one by Arthur Eddington (or rather, it’s based upon those books and the huge literature that they have spawned). The idea is that the properties physicists refer to – mass, spin and charge – are identical to forms of consciousness, and that we can make sense of this identity because physics only describes the behavioural properties of physical properties and is silent on their intrinsic nature. Now there are all sorts of ways you can criticise that account, and I’m sure some will doubt it’s ultimately incoherent. But I find it bizarre that Massimo and Daniel don’t even describe my view but instead dismiss me on the grounds that I don’t have a view.

Later in the discussion, the issue of empirical evidence comes up. Massimo correctly reports that I don’t think that a case can be made for panpsychism over materialism on the basis of empirical evidence. However, he then goes on to say that when he challenged me on this, I said that ‘the very asking for empirical evidence assumes a physicalist view’ (38:20). This is something Massimo also pressed in this recent popular article, suggesting I put metaphysics before epistemology and that I provide no epistemological justification for my view. I’ve looked back at the letters I wrote, and I have no absolutely no idea how Massimo is reaching this interpretation of what I said.

In fact, for better or worse, I do have an argument for the seemingly odd claim that we have grounds for believing panpsychism despite not having straightforward empirical grounds for believing it. My reasoning is as follows. We tend to think of the aim of science as accounting for the data of public observation and experiment. The trouble is, consciousness is not known about in this way. We know that consciousness exists not on the basis of observation and experiment but on the basis of our immediate awareness of our feelings and experiences. Hence, if we religiously follow the dictum ‘only believe in the things that are known about on the basis of public observation and experiment’, we’d have no grounds for postulating consciousness at all (the illusionists, also discussed in this video, are wonderfully consistent on this point).

Therefore, if we want a science of consciousness, we need to expand our conception of the data science needs to account for. We need to be looking for the simplest theory that can account for both the data of public observation and experiment and the first-person reality of consciousness. I think panpsychism is that theory (partly because I think it can be demonstrated that materialism can’t account for consciousness), and this constitutes the basis of my epistemological justification of it.

Now there are all sorts of things you can attack about the above position, and the very interesting claims Daniel and Massimo make later in the discussion could certainly be used in this way. But if you’re going to discuss my case for panpsychism surely you should at least say what that case is. And the stuff Massimo attributes to me about ‘the request for empirical evidence assumes physicalism’ is wild misinterpretation.

Later in the discussion, Daniel and Massimo agree that idealism is empirically equivalent to materialism, and Daniel mocks Samuel Johnson for trying to refute Berkeley’s idealism by kicking a stone. There is a deep irony here: the Russell-Eddington inspired panpsychism I defend is also empirically equivalent to materialism, which makes Hossenfelder’s post the contemporary equivalent of Johnson’s stone-kicking. Furthermore, given that Massimo accepts that materialism and idealism are empirically equivalent, surely by his own strict empiricism he should be agnostic about which view is true. Perhaps he is, but one doesn’t get that impression.

I’m sure there’ll be lots of people who watch this video and say, ‘Oh my god, Goff defends a view without any evidence, he’s such an idiot.’ But I think anyone fair-minded who’s read, watched, or listened to anything I’ve said on this, whether they agree with me or not, will recognise that my view is not being charitably represented here. In fact, it’s barely represented at all.