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Why Physicalism is Wrong

Grant Bartley argues that to say the mind is physical is an abuse of language.

The most widely accepted attempt at describing the nature of embodied thought in this materialistic age is called physicalism. (It has a variant called materialism, but I’ll use the terms interchangeably.) There are many nuanced versions of physicalism, but in its basic form, it says that all the mental things – sensations, thoughts, ideas, all experiences – are really physical things: matter, energy and physical processes. But does such an idea make sense? Can it mean anything meaningful to say that the contents of minds are physical? I say no.

Let me start by saying that the debate about how to describe the nature of the mind is at its heart an argument about the proper language in which to do so. Although this might make the debate sound trivial or fussy, it is not. This is firstly because what we say about the mind will be fundamental for our understanding of the nature of reality, so to accurately describe the nature of the mind is not trivial but vital. Secondly, using the correct language is what makes the difference between describing something truthfully rather than falsely. And I want to say that describing the mind as ‘physical’ is a grossly false way of speaking about the mind that will hold metaphysics back for as long as people talk that way. In fact, I will argue that people can only believe physicalism because they haven’t thought hard enough about what its core ideas actually imply or they are using the term ‘physical’ so imprecisely that it’s meaningless.

Brains of Sand

As a scientifically-aware thinker, you’ll recognize that the world is in many ways like a meticulous material machine: physical events cause physical events, and in this way the physical universe is kept in business. Physicalists say all events can be explained completely by causal chains of previous physical events. This was, roughly, the scientific worldview before the discovery of quantum physics. Now we know, however, that some events at a subatomic level are affected by whether there is an observing mind.

Since the brain is a physical object, the changing states of the brain can be explained with reference to electrochemical processes and so on. However, the physicalist goes further, and, ignoring quantum mechanics, claims that since scientists can give entirely physical explanations for what happens in the physical world, not only do we not need anything non-physical in our explanation of the world, there is no room for anything non-physical in our explanation of how this big machine runs. Therefore everything must be physical, even experiences and the mind.

The most extreme version of this idea is eliminative materialism. This says that distinct minds and experiences don’t exist: there are only brains and their physical activities.

As just formulated, this is an absurd doctrine. If it were true as stated, you could not be having experiences, such as the experiences you’re having now, and the perpetrators of this doctrine would have to claim themselves to be mindless zombies or automata, writing their books mindlessly. Even to say that experience is an illusion ignores the fact that a supposed ‘illusion’ of having an experience is still having an experience; and for an experience to exist, all that is necessary is that the experience is experienced, regardless of whatever else one might say about its nature or cause.

Well, a clearer-minded materialist might say, “You do have experience; but to speak in terms of experience as something extra to brain activity is simply to misrepresent brain activity. In the end, there is only the physical activity of the brain, and experience is this brain activity.” This variant is often called reductive materialism. This says that science will eventually be able to describe all mind states in the same terms in which we describe brain states.

However, I would reply that this idea doesn’t make sense, since experiences must be defined as not being brain activity. This is because experience content is only specifiable through properties that are distinctly different from brains and brain activity. Indeed, if the mind were not distinctly different from the brain, we could never have come up with the distinct concept of ‘mind’.

Allow me to try and justify this response.

Any usable understanding of the two terms must accept that ‘mental’ and ‘physical’ mean different things. You already know that ‘mental’ and ‘physical’ are different concepts. For instance, you do not conceive your experience of the sounds you hear as being the same sort of thing as the vibration of the molecules streaming through the air to catalyse the experience, nor even the activity of brain cells responsible for generating the sound experience. You recognise that one type of thing is mental and the others are physical. And I think most people distinguish ‘mental’ from ‘physical’ by recognising that the words refer to aspects of the world displaying distinctly different properties. So, the reductive physicalist claim that there is only physical brain stuff amounts to a denial of this evident fact that thoughts have a distinctly different character to physical things. But they evidently do have different characteristics. I challenge any physicalist to deny it with plausible justification.

Moreover, although these physicalists might now bravely assert that experiences will eventually be able to be talked about in entirely physical terms, they are at a loss even to begin to show how this is to be done. I assert it cannot be done, since experiences are distinctly not physical things. So I also challenge any physicalist to show I’m wrong by demonstrating how a single experience can be described in precisely the same terms as a brain state and not just correlated with that brain state.

Further Interpretations of Materialism/Physicalism

Another variant of materialism is called property materialism or property dualism. This says that experiences are properties of brains in just the same way that any physical object has properties – that a beach ball has the properties of being spherical and looking red, for instance.

Unfortunately, to say that ‘experiences are properties of brains’ is either a relatively uninformative truism, if it simply means ‘certain mind states accompany certain brain states’, or it’s another fallacious way of expressing the nature of minds.

For a start, experiences are not properties of brains in the same sort of way that the physical properties of brains are properties of brains. The physical properties of brains are the sorts of properties typical of any physical thing – such as brains having physical shape, or brain cells behaving in characteristically physical ways, such as reacting chemically with each other. Experiences are not properties in this physical way. In fact, this concept is called ‘property dualism’ just because it recognises that mind states have their own properties – that is, that contents of mind have experiential qualities – for instance, the gold sheen of the gold mountain I hope you’re now imagining. So how about this analogy? Someone might say that your teeth are simply a property of your mouth. While in some sense that might be true, it’s not true if it’s taken to mean that your teeth are not distinct things from your mouth as a whole. So it is with the mind and the brain. Mind is not just another part of the brain.

The issue here is one of substance. When we say that properties are material properties, we mean that they are the properties of some material substance – that matter is the substance which has these properties. The property dualist is asserting that the substance of mental properties is also matter – the same brain matter that has its material properties. But this is false. The substance of experience is experience. I mean by this that the exact (substantial) nature of experience is experience itself. What any experience is in itself, is the experience just as it is experienced.

In fact I think the simplest argument that mind and brain are different is that the properties of thoughts and experiences are utterly distinct from the properties of matter. Thus we can say that the mind and its contents have mental properties – for example, sensations such as an experience of red (philosophers call these qualia), or all the distinct properties of thought, emotion, intellect – whereas the brain has physical properties such as weight and spatial extension. Yet how do you tell anything apart from anything else, if not through the differences in their properties? Consider a hippo and the Eiffel Tower. How do we know they’re different things, apart from their properties?

Specifying which sort of thing we’re talking about via its properties is a most fundamental means of distinguishing one thing from another (The widely-accepted claim that no two objects can have exactly the same properties is known as Leibniz’s Law). Yet it’s impossible to talk about the contents of mind in the same terms that we talk about physical objects or behaviour. If they have nothing in common, how can they be the same thing? And why make a special exception here we don’t make anywhere else?

It seems then that the only warrant for making experience a property of brains would be that experiences are generated by brains. But is water a property of a tap just because every time you turn on a tap you get water? Well, in an uninformative sense of ‘property’, the answer is ‘yes’. But the water is not a property of the tap in the same intrinsic sense that ‘being metallic’ or ‘being curved’ is a property of the tap. Further, saying the water is a property of the tap tells us nothing interesting about the relationship between the water and the tap. Similarly, even if we were to allow the misleading property dualist terminology, the mind-body problem would remain, rephrased as the question, “Why do brains in particular have these mental properties?”

So ‘property materialism’ is at best a misleading way of merely affirming that brain states have experiences associated with them, and at worst, a misrepresentation of the relationship between properties and the substances that have those properties. And since it is so misleading, this terminology should be avoided. A better approach is instead what I call naturalistic dualism. Naturalistic dualism is the idea that the mind’s contents are created through the activity of the brain, but that the mind and the brain are different things, indeed, different types of thing.

Often, physicalism is simply assumed by physicalists to be the idea that all experiences are created by the activity of physical brains. I believe the neurological evidence does show that experiences are created through brain activity; but I nevertheless do not call myself a physicalist, because this is not what the word ‘physical’ means. At the very least, physical means having physical properties. So categorising experiences or minds as ‘physical’ or ‘material’ on the basis of their being generated through brain activity is the wrong language just because minds have no physical properties. Again, the experiences created by brain activity are a totally different type of thing from the activity creating them. Let’s again consider taps. Just because a tap produces water doesn’t mean that the water is the same stuff as the tap. So it is with brains and the experiences they produce. Why should the mind, produced by the brain, thereby be the same stuff or the same sort of thing as the brain producing it? Raymond Tallis has made the good point in this regard that the only thing ever thought to produce itself was the God of the scholastics. The truth is rather that although experiences come about through a physical process, the process produces something non-physical – a mind! So if all that a physicalist means when they assert that mental activities are physical, is that brain activities are necessary for the creation of the embodied mind, then although the latter seems true, physicalist language is being asserted here at the expense of truth, since it is utterly misleading as to the nature of mind in particular, and of reality in general. Again, it is more honest and accurate to call the mind-brain situation a naturalistic dualism.

Going Deeper into the Linguistic Confusion

Let’s look at the conceptual distinction between mental and physical in more detail, as I want to drive home how meaningless physicalism is.

Allow me to provisionally but plausibly define ‘mental’ as referring to the realm of things that exist precisely as present to awareness. The concept ‘physical’ must mean something distinct from and even excluding that, otherwise, to say ‘experiences are physical’ would be to say that these particular so-called ‘physical’ things exist entirely to minds! But this idea cannot be physicalism, since physicalism is not the doctrine that some physical things exist entirely to minds – that some physical things are really mental in nature! (That concept is called idealism.)

I imagine that may not be entirely clear, so let me put the argument differently. To say that ‘experiences are physical things’ is to not recognize what the word ‘physical’ means or implies. This is primarily because essential to our concept of ‘physical’ is the idea that a physical thing is something of which there will always be aspects not fully revealed in experience. For instance, to say that an apple is a physical object, is, among other things, to say that an apple will never be all and only what you or anyone else experiences of it. And if the apple did exist entirely as experiences of it, this would on the contrary be good reason to call it a mental rather than a physical thing…

apple cut
Physical things are by definition not only our experiences. So, experiences themselves cannot be physical things.

Not convinced? Consider then instead that core to our concept of physical is that a physical thing exists as part of a world of physical causation that operates independently of our experience of it. That is to say, our experience of the physical world is as if that world is joined together through the behaviour of things external to our minds. For example, we assume, often implicitly, but sometimes explicitly, that our experience of the physical world shows that it is not explainable in terms of it being simply one unconnected experience after another, but only in terms of laws that apply to physical objects that have an existence separate from our experience of them. For example, we can (usually) predict where and when a probe is going to land on Mars even when nobody is in contact with it; or we can come to perceive light that originated from quasars long before there was conscious life on Earth, or even an Earth; or we can leave a computer running an app while we’re out; or assume the fridge is still working when we’re not looking at it; or we see a ball disappear behind a wall, and then reappear on the other side as it rolls along; and so on. These ideas all rely on the idea that physical things exist independent of minds. So by definition, a physical object is not only or purely what is in the contents of experience. This means, conversely, that anything that is purely in a mind, is not physical by definition! So, again, mental things are not physical.

These arguments emphasise that by definition ‘physical’ refers to the sort of thing which does not exist as thoughts do. Given this, to say that thoughts and experiences are physical things contradicts the concepts of both physical and mental. In other words, to assert physicalism is either to not know what the words ‘mind’ and ‘physical’ mean, or to deny their meaning.

Alternatively, if we say that experiences are really physical, then because of what ‘physical’ means, we must be denying that experiences are distinctly mental. “Exactly!” the materialist might reply: “What you think of as belonging to a distinct category you call ‘mental’ is only part of the material world.” But I’d be obliged to then ask, “What does an assertion of the purely physical nature of experiences mean, now? Is it that experiences don’t exist distinctly as experiences?” If we know anything at all, it is that experiences exist as experiences! (We know everything through experience, in one way or another, so the first thing we know is the reality of experience.) Isn’t saying that our mind states are characteristically physical therefore a denial that our mind states are characteristically mind states? But that’s meaningless!

In fact, if ‘physical’ didn’t imply something distinct from ‘mental’, there would be no physical/mental conceptual distinction by which we could formulate the hard problem of how the material brain and mental experiences relate. But we can see what the problem is because we know that ‘mental’ refers to things as they exist experientially, or to a mind, whereas ‘material’ or ‘physical’ refers to things by definition existing not solely in minds. (This doesn’t mean that without the language that distinguishes mental from physical the problem of how thought is embodied wouldn’t exist; only that without the language, we wouldn’t have the concepts of mental and physical to think about what the problem involves.)

Rather than try to deny the distinct nature of experience alongside the distinct nature of the physical, a less incredible interpretation of what physicalists are trying to do would be that they’re trying to redefine ‘physical’ so that ‘physical’ also refers to what I’ve been calling the distinctly mental. Perhaps many a physicalist would respond here, “Yes, that’s exactly what we’re trying to do – say that the list of physical things also includes experiences, thoughts, etc – even though we obviously do not deny that experiences have a distinctly ‘experiential’ nature.” In this case, they would be saying that the term ‘physical’ now includes the experiential or mental aspects of the world, and thus that ‘mind’ has become part of what ‘material’ means. By this handy redefinition, experiences have become physical and the mind-body problem has been solved, since everything is now physical in nature, and so there’s no divide of different natures to have to cross from brains to minds.

However, what would it mean to include experiences and thoughts in our list of physical things? It would be attempting to assert that the physical world which was essentially defined in terms of being distinct from experiences (see above) now includes experiences. Again, this is contradicting the very idea of ‘physical’ – once more demonstrating the emptiness and uselessness of the doctrine of physicalism. Indeed, a redefinition of the concept of ‘physical’ to incorporate the avowedly ‘mental’ would drain the concept of ‘physical’ of all meaning distinct from ‘mental’, so that physicalists would be left saying nothing. In other words, denying the distinction between the concepts of ‘mind’ and ‘matter’ makes both words meaningless.

I don’t think that’s what the physicalists think they’re trying to do. I’m pretty sure that when they say ‘physical’, they’re not really trying to surreptitiously say that ‘physical’ incorporates ‘mental’ as well as ‘physical’. However, I’m equally sure that the assertion that “everything is physical, and this includes experiences” could only ever amount to an incoherent idea. So it seems that the only way physicalism or materialism can be coherently expressed, is as asserting the patently false eliminativist proposition that there are only physical properties in the world.

Final Thoughts About Mind & Brain

Another telling point is that even if we were in whatever way to allow a physicalist’s dodgy redefinition of the meaning of ‘physical’ to include ‘mental’, this wouldn’t eliminate the mind-body problem. The hard problem of consciousness still remains for anyone, whatever their view about the nature of mind and brain. The only thing that physicalism does here, is to require the problem to be rephrased in ridiculous terms, becoming, for example, “How does the non-experiential aspect of the physical world generate the distinctly experiential aspect of the physical world?” Why not more honestly ask, “How does the distinctly physical generate the distinctly mental?”

The conceptual distinction between mental and physical is vital. In fact it is metaphysically fundamental, being, I believe, the most fundamental division of the kinds of things that exist. So if we miss making this distinction, then we misunderstand the nature of reality. As if that’s not bad enough, this also has significant implications for psychology. For example, whitewashing the mind/brain distinction could eliminate the difference for practitioners between whether a psychological problem is physically-originated due to a brain dysfunction or brain damage, or mentally-sourced due to traumatic experience. This conceptual confusion could have dangerous implications for treatment.

So for all these reasons, ‘physical’ is a basically misleading word to describe the mind. Indeed, it’s a semantic abomination.

We already have a good word to encapsulate the nature of mind: ‘mental’. So let’s be honest and clear about the nature of reality, and say that there are both physical and mental things: that there are both brains and minds.

© Grant Bartley 2018

Grant Bartley edits Philosophy Now.

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