Introduction

You probably agree with the two following statements: 1) you have a mind, and 2) you have a body. Both of these statements seem obvious enough. But what’s less obvious is the relation between these two statements. That is, what’s the relationship between your mind and your body? Is your mind actually just a part of your body, or is it something else entirely? Or maybe your body is really just a part of your mind. In thinking through these questions, you might begin to wonder, what even is a mind? And do you even have a mind at all?

In this chapter, we’ll explore the mind-body problem: the question of the relationship between mind and body. In doing so, we’ll consider different views about what the mind is, including dualism, physicalism, idealism, behaviorism, and functionalism. But first, we need to start with a more basic metaphysical question: What substances is the world made up of?

Basic Ontology

Before we can talk about the mind, we need to get a basic introduction to ontology. Ontology is sometimes thought of as the study of what exists. But it’s more than simply cataloguing all the objects that exist in the universe. It’s about figuring out the exact nature of all of those objects’ existence.

For instance, I know that tables and chairs exist. But how do they exist? There’s a lot of interesting philosophical questions bound up in that single question, but for now, we’ll focus on just one that will be relevant for us. What are the underlying substances which allows for the existence of tables and chairs? Or put another way, what’s the most basic thing or things that our tables and chairs are made out of? For the table and chair, we might say, the atom (we can of course, be more precise, but we’ll stick to talking about atoms out of ease). The existence of the atom is what allows all of the physical objects in the universe to exist. At the end of the day, all of our physical objects are made out of physical matter which means that every physical thing can be broken down into atoms and nothing more.

So, in answering our question about what underlying substances exist, we should at least include physical matter or the atom in our answer. But our question isn’t just about what substance underlies the existence of physical objects. Rather, we want to know what underlies the existence of everything in the universe. The deeper philosophical question here is this: is there something in the universe that is not made up of atoms? Is there something made up of non-physical substance? And if there is something made up of a non-physical substance, we need to know what that non-physical substance is.

If we accept that all that really exists are physical objects, then there is only one substance that exists: physical matter. This position is called Metaphysical Materialism. The view is a fairly straightforward one. And if you’re scientifically inclined, you might already accept something like the metaphysical materialist position. We can go back to our example of the table.

We all agree that the table is just made up of atoms. But we can be more precise about what we mean by this. If I wanted to fully understand any given table, then what I need to do is understand what that table is made out of. According to the metaphysical materialist, that means all I need to do is understand all of the atoms that make up that table. I need to know some things about the physics of atoms. I need to know how the atoms are organized and interact such that they give the table the properties that it has like its solidity, shape, and color. And that’s all that I need to know to fully understand the table.

And of course, we’re not just talking about tables. We’re talking about everything that exists in the universe. Everything exists basically the same way that tables exist. Everything is really just a complex collection of atoms, and all there is to understanding that thing is to understand how those atoms come together to give rise to the more complex properties of those objects.

We of course might not accept that everything is exclusively made up of physical matter. We might think that in addition to physical matter, there also exists some non-physical substance as well. The Metaphysical Dualist holds—as their name suggests—that there are two substances that make up all of the objects in our universe: both physical matter and some non-physical substance.

Importantly, the metaphysical dualist doesn’t think everything is made up of two substances. They’re perfectly happy to say that the metaphysical materialist is right about tables. The metaphysical dualist wants to say that not everything is like a table. There are some things that exist which are made up of more than atoms. Some objects include a non-physical substance. And some objects are entirely made up of this non-physical substance.

We know what physical matter is. It’s ultimately an atom. And I can pretty easily point out what objects are made up of atoms. But if there is some non-physical substance, what is it? And what things are made up of this non-physical substance? To answer the second question first, you might say the soul or God if you’re a religious person. But—and we’ll come back to this in a later section—the mind is another option here.

There’s no easy answer to the first question, however. After all, there’s no non-physical analogue for the atom. But we might figure out what this non-physical substance might be like by contrasting it with the atom. Atoms are physical. What that means is they exist in space, and I can make contact with them. I can touch an atom. Whenever I put my hand on a table, I’m making physical contact with some of the atoms that the table is made of. And I can do this because those atoms occupy a location in the universe. Our non-physical substance is not like this. It doesn’t occupy a physical location in the universe. And because it doesn’t, we can’t come into contact with it. We’ll return to this when we start talking about the mind in the next section.

If we open up the possibility of there existing a non-physical substance, then we can take the opposite of the metaphysical materialist position. The metaphysical materialist accepts that physical matter exists and rejects the existence of a non-physical substance. So, one could also accept that the non-physical substance exists and rejects the existence of physical matter. This is the position of the Metaphysical Idealist. According to metaphysical idealism, everything in the universe—even seeming physical objects like tables and chairs—are really made up exclusively non-physical substances.

So far, we’ve avoided talking about minds, but we can’t do that while talking about the metaphysical idealist position. The non-physical substance is essentially mental for the metaphysical idealist. What this ultimately means is that all the objects that appear to be physical are, in some sense, a manifestation of our minds. Or, put another way, the existence of the seeming physical world depends on the existence of our minds. Without minds to perceive the seemingly physical world, it wouldn’t exist.

We’ll talk more about the idealist position in the next section. But now that we have all of our ontological positions on the table, it’s time to start talking about the mind.

The Mind-Body Problem

With all of our ontological positions laid out, we can start talking about the ontology of the mind. We’re now in a position to ask, what are minds made up of. And we can also start to think about how minds are related to our (potentially) physical bodies. Importantly in asking questions about the ontology of the mind, we’ll be asking questions about the ontology of mental states. Mental states are what philosophers call the different kinds of psychological states you might have or be in. Think beliefs, emotions, memories, pain—really anything that might be studied by a psychologist. With all that said, let’s begin with physicalism.

Physicalism

If you find yourself accepting a materialist ontology, then you’re going to need to explain the mind and mental states in physical terms. That is, you’re going to need to explain how our mental states are ultimately made up of atoms. The easiest way to do that is by identifying mental states with something we already agree can be reduced to atoms: the brain. This is the physicalist position. Brains are made up of cells, and cells are physical objects that can be reduced to atoms. So, if we can explain minds in terms of brains, then we have easy way to think about how minds can be made up of physical matter.

The claim that the physicalist wants to make is a kind of identity claim. That is, they want to say that the mind is identical to the brain, such that once I have given you a complete explanation of how the brain works, I should have also given you a complete explanation of how the mind works as well. Importantly, the physicalist also wants to be more precise than to talk about minds and brains generally. They want to hone in on specific psychological events, like emotions or pains. So, they end up saying not that minds are identical to brains (although they do think something like this), but that mental states are identical to brain states.

The initial rationale for this position comes from the fact that there does seem to be an important connection between the brain and the mind. In fact, our best neuroscience seems to show that every mental state correlates with a specific physical state or process in the brain. So, every time I’m having a specific mental event, a specific brain event seems to co-occur with that mental event. For instance, when a person experiences pain, there is a specific pattern of neural activity in their brain, particularly the firing of certain types of nerve fibers known as c-fibers. So, when you accidentally touch a hot stove, the sensation of pain you feel is directly a result of the activation of specific neurons in your brain, which correspond to the experience of pain.

So, in the physicalist account we get a pretty simple account of the ontology of the mind. It’s just the brain. We also have an easy answer to the question of how the mind and body are related. The mind is just a part of the body. But despite its simplicity, there’s a couple critiques we offer against the view.

Importantly, the physicalist doesn’t think there is mere correlation between mental states and brain states. They’re supposed to be identical. What that means is that brain states don’t just co-occur with their corresponding mental states, nor are they just the cause of the mental states. They are the mental states. To claim that two things are identical is to claim that they share all the same properties and features. And crucially, it shouldn’t even be possible to imagine them having different properties. For example, if bachelors and unmarried men are identical, every property that bachelors have, unmarried men must have that property as well. So, if I can imagine a married bachelor, then bachelors aren’t identical to unmarried men. But since I can’t do that, that means they are in fact identical. The same must be true of pain and c-fiber finings as well.

But here’s a problem, I can imagine an instance of pain without an instance of c-fiber firings, and I can imagine an instance of c-fiber firings without an instance of pain. Let’s take the first example. Imagine yourself as a disembodied mind. That is, you’re just a mind floating in space—no body, and thus no brain. Can you imagine feeling pain as this disembodied mind? If yes, then you can imagine pain occurring without c-fibers firing. That means that pain has different properties than c-fiber firings, which means that they cannot be identical.

If you don’t find that version plausible, then consider this other example. Some people suffer from a condition called congenital insensitivity to pain. These are people born without the ability to experience pain at all. Crucially their c-fibers are intact and firing. But again, they lack the ability to experience pain. So, they have c-fibers that fire, but no pain. So again, pain and c-fibers have different properties and cannot be identical.

Maybe you didn’t find this critique convincing. So, let’s look at another one. Philosophers thinking about minds and mental states generally think mental states need to be Multiply Realizable. That is, the same mental state needs to be able to be realized in different kinds of physical systems. Here’s what we mean by this. Humans aren’t the only things that feel pain. Lots of other animals feel pain as well. And we can tell by examining behavior. If I step on my cat’s paw, he’s going to meow and attempt to protect his paw from being damaged. When someone steps on my foot, I’m going to yelp and attempt to protect my foot from being damaged. That we’re exhibiting the same behavior is at least some evidence that we’re both experiencing the same kind of mental state.

So, what’s the problem here? The physicalist claims that pain is identical to c-fiber firings. That means anytime any creature experiences something we want to call pain, they better have c-fiber firings. Otherwise, the physicalist can’t say they’re experiencing pain. Now, this might now be a problem with my cat. He might have c-fibers. This becomes a problem when we begin to consider radically different forms of life. For instance, imagine a sophisticated robot designed to simulate human-like behavior, including responses to external stimuli that typically cause pain in humans. Despite its ability to behave as though it’s in pain, this robot lacks the biological nervous system found in humans, including c-fibers. Therefore, if pain is identical to c-fiber firings, we cannot say that the robot who behaves as though it experiences pain does actually experience pain. We don’t need to consider science fiction examples to make our point. We can examine the octopus. While octopuses do experience pain and exhibit avoidance behaviors in response to pain inducing stimuli, their nervous systems are vastly different from those of humans. Octopuses lack c-fibers, yet they still display behaviors indicative of pain. So, the octopus too lacks pain according to the physicalist.

So, while the physicalist has a simple solution to the mind-body problem, it comes with its own problems. And while the physicalist has responses to these problems, it’s time for us to move on to dualism.

Dualism

We can now move on to Substance Dualism (Hereafter just dualism). The dualist accepts—as their name suggests—a dualistic ontology. That is, they think there are two substances that make up the universe. And in particular, what the dualist claims is that minds and mental states are included in the category of objects that are ultimately made up of some non-physical substance.

The case for dualism picks up right where our first argument against physicalism left off. Remember, according to this argument, we can’t claim that mental states like pain are identical to physical states like c-fibers firing because we can imagine having one without having the other. So, they have different properties, and can’t be identical. But there’s still work that needs to be done to get from the claim that minds and brains are not identical to the claim that minds are non-physical.

The dualist does this by giving us reasons as to why we should think of minds and mental states as non-physical given that they’re not identical to their physical correlates. There are a couple differences between minds and brains (or bodies) that go back to Descartes which will help us understand the dualist’s argument. First, minds are thinking things, but bodies aren’t. Thought is the fundamental feature of a mind. It’s just what the mind does. But bodies don’t think. They’re just hunks of matter.

Second, and more importantly, remember when we talked about metaphysical dualism earlier. When we tried to talk about this non-physical substance earlier, we didn’t say much about it, but one thing we did note is that this non-physical substance doesn’t have a spatial location. This is why the argument against the identity of mental states and brain states serves as evidence for the claim that mental states are non-physical. Remember the first argument, I can imagine being a disembodied being and still imagine feeling pain. How can this be the case? The dualist wants to say because the pain doesn’t have a spatial location. If it doesn’t have a spatial location, that should both cast doubt on the idea that it is physical and give us some reason to think it’s non-physical.

Even in making this point we need not rely on imaginary scenarios. Consider the case of phantom limb. People who have a limb amputated will still find that they feel pain in the amputated limb. That is, after my arm gets amputated, I still feel pain in my arm. But the arm is no longer there, so how can I feel pain in a physical object that doesn’t exist anymore? It must be because the pain was never really physical to begin with. And so, it didn’t have a spatial location.

So, with a sketch of the dualist position, let’s move on to our critiques of the view. First, I mentioned earlier that physicalists have a response to the argument above. This argument centers on the role of imagination as well as the development of a concept. An important feature of this argument against physicalism and for dualism is that we can imagine mental states and brain states as having different properties. So that means that they do have different properties.

Let’s go back to our example of bachelors and unmarried men. These concepts are identical. And they’re identical because they mean the exact same thing. The definition of a bachelor is an unmarried man. And so, if I know what these two concepts mean in their entirety, then I cannot imagine a difference in properties between the two concepts. This is what the physicalist wants to claim about pain and c-fiber firings. The definition of pain is c-fiber firings, and if I know this, then I shouldn’t be able to understand these two things as having different properties.

Of course, I can understand pain as having different properties from c-fiber firings. So where does that leave the physicalist? Their response is that we don’t yet have a fully developed scientific concept of pain. And because we don’t have this fully developed concept, this allows us to wrongly imagine that pain is different from c-fiber firings. Consider this example. Suppose you live in the early 19th century before the discovery that water’s chemical structure is H2O. Some scientists begin to suggest as much, but without full proof of the claim. We could make a version against physicalism, but against the identity of water and H2O. I can imagine water containing no oxygen at all, but I cannot imagine H2O lacking oxygen. So, they have different properties and cannot be identical. We can immediately recognize now how silly such an argument is. But the physicalist wants to claim that this is exactly what’s going on in the argument against the identity of pain and c-fiber firings. In the future when we have an adequate scientific understanding of pain, one will not be able to know what pain is and still imagine that it has different properties from c-fiber firings.

With that critique out of the way, let’s move on to a second one. You’ll notice that thus far we haven’t talked about how dualism solves the mind-body problem. That is, we haven’t addressed how our non-physical minds interact with our physical bodies. This is because the mind-body problem is a problem that arises when one is a dualist. We care about the nature of the mind for many reasons. But one of the main reasons we care about the mind is because our minds are the cause of our behaviors. Why is understanding pain important? Because it’s my pain that motives me to yelp and grab my arm when it’s hit. It’s my sadness that causes me to cry. We want to understand why and how our pain causes our behaviors. But this is a problem for the dualist. And it’s a problem because of how we understand causality.

The scientific picture that we get of cause is—among philosophers—sometimes known as efficient cause. How does anything cause the movement of another object? Well according to the picture we get from physics, motion is transferred from one object to another. When a cue ball hits an 8-ball, the motion of the cue ball is transferred from the cue ball to the 8-ball. How is motion transferred? The cue ball collides with the 8-ball; It makes physical contact with the 8-ball. This is how we understand cause. And you might already see where the problem is for the dualist. If cause is something that happens when one object makes physical contact with another object, then how can mental states cause behavior.

After all, if these mental states are non-physical, then how could they possibly come into contact with our physical bodies, such that they can make them move in the relevant ways? This is a significant problem because if the dualist can’t answer this question, then we have no way of explaining how our minds and mental states are responsible for our behaviors. And that’s an unacceptable consequence, especially if you think we can have a scientific psychology.

Many early dualists attempted to answer this question. Descartes for instance suggested that the pineal gland is the physical part of the brain that the mind occupied. And it was here that it interacted with our physical bodies to produce physical effects. But at least as far as modern neuroscience tells us the pineal gland is merely a part of the brain responsible for producing and regulating hormones. Other dualists suggested a view called occasionalism. According to this view, every time we find ourselves in a relevant mental state that we believe to cause behavior, it’s God who makes it the case that we behave in a relevant. But it’s a bit troubling to suggest that every time I’m crying it’s not because I’m sad, but rather it’s caused by God’s divine will.

The point in laying out these responses is not to dismiss them or poke fun at them, but rather to show that this problem is serious enough that it can require creative solutions. And contemporary dualists are up to the challenge of offering creative but more plausible solutions. We won’t discuss those here. Instead, we’ll move on toward idealism.

Idealism

We can now move on to Idealism. We didn’t talk that much about metaphysical idealism earlier, but it’s the position that everything in the universe, even what appears to be physical is actually non-physical. But the idealist position doesn’t just suggest that everything is non-physical, but rather that everything which exists is inherently mental. This is their solution to the mind body problem. Everything was always metal to begin with event apparently physical objects like bodies or tables. So, not only is the table in front of you right now not made up of physical matter, it’s also somehow a product of my mind.

According to the idealist, everything that exists out there in the world (let’s exclude other people from this group) exists only insofar as it is perceived. This is what it means to say that everything is inherently mental. The objects of the world only exist when they exist in the mind of a person. What this suggests is that the objects of the world are in some sense constructed by the perceiver. Philosophers sometimes think of hallucinations as the perception of an object that isn’t really there. So, when it looks to me like there is a tomato on the counter, but there isn’t one there at all, I’m hallucinating. It’s my mind that is constructing the tomato. We might think of the idealist view as suggesting that all of perception is a kind of hallucination. I never perceive things that are actually there in the world.

You might be tempted to immediately reject the idealist position. It’s a fairly hard sell to suggest that all the seemingly physical objects of the universe are not only non-physical, but also products of my own mind. And it’s also hard to accept that I’m actually just hallucinating about reality 24/7. But there’s something really important in this view that needs to be taken seriously. When you look at an object like a tomato, do you actually see the object as it really is? You might want to say yes but consider that you see the tomato as a three-dimensional object. Now consider that your retina is only two-dimensional. How can your retina be capable of only directly perceiving height and length of objects give rise to visual experiences that include height, length, and depth? The answer is it doesn’t—at least not on its own. The brain helps out.

A significant chunk of what contemporary vision science shows us is that much of what we perceive is the product of our brain constructing a picture of the world. We’re not cameras that passively record the world through vision. We construct the world. So, while this doesn’t get us to the strong claim where everything is a hallucination, it does push us in an idealist direction because every object that I perceive in the world is at least partially constructed by my mind. And so, everything is in some sense mental because I never make direct contact with the world. My own mind structures how I perceive and experience the world.

With a better understanding of idealism, we can now look at two critiques of the view. We’ve sort of hinted at one of these critiques already, but we can make it more explicit. I suggested that the idealist thinks everything is basically a hallucination. That is, I’m perceiving objects which are not really there. And what that ultimately means is that there is no real mind-independent world. That is, if I think everything is constructed by my mind, then the world out there doesn’t exist without me being aware of it. So, what happens when you and I look away from the tree? Does the tree cease to exist? If no one is currently perceiving it, then it must cease to exist on the idealist picture. But that’s a deeply odd consequence of the view.

Also, there’s a second related worry here. You and I can both see the tree. And we can talk about it. We can describe what the tree looks like to each other. And as we do this, we’ll realize we each see a tree that looks pretty similar—identical even—to the tree the other sees. But there’s two questions that arise for the idealist here. First, whose mind is constructing the tree? The tree only exists insofar as it’s perceived. So, whose perception is giving rise to the tree? Yours or mine? Maybe some combination? Whatever the answer the idealists need to be able to answer this question as well as this other one: Why do our perceptions of the tree look identical if there is no mind independent tree on which our experience is based? The reason we want to say our experiences of the tree are identical is because we can say that we’re looking at the same tree. And I can point out a physical object to which that tree refers. But the idealist doesn’t have that option. And so, they can’t offer up an easy response to this question.

Much of the way early idealists attempted to answer these challenges was by appealing to God. But that’s a bit too far afield from what we’re talking about in this chapter. So, we’re going to move on to our next view: behaviorism.

Behaviorism

We can now move on to another view which accepts a materialist ontology. This view is Philosophical Behaviorism. You might have come across behaviorism before, especially if you have a background in psychology. In psychology, behaviorism is the view that if we want to understand human psychology, the best way to do that is to understand human behavior. And specifically, we want to understand how behavior arises from or is caused by external stimuli. Philosophical behaviorism is related to the kind of behaviorism that psychologists talk about, but it’s importantly its own distinct view. According to the philosophical behaviorist, all of our mental states can be explained fully by understanding them as behavioral dispositions. Rather than understanding our mental states like beliefs, emotions, and pains as internal events, we should understand them as behaviors. And specifically, we want to understand them as behavioral dispositions.

But what’s a disposition? A disposition refers to a tendency or readiness to behave in a certain way in specific circumstances. A disposition is a kind of property that an object can have. But it’s different from other properties that objects might have in that an object can have a dispositional property even when that property isn’t manifest in the object at a particular moment. Consider we have a vase. We can figure out a significant set of the vase’s properties by simply looking at it. I can see that the vase is clear, has a blue tint, is a particular shape and size, and so on. These properties are always there. I can always see that the vase has these properties. But I might want to say the vase has other properties too—ones that I can’t see. For instance, the vase is fragile. But I don’t see the fragility when I look at the vase. This is a dispositional property of the vase. Rather than being an apparent property that objects always have, dispositional properties are ways that objects tend to behave in particular circumstances. To say that a vase is fragile, is to say that under certain circumstances that vase will shatter—like when it’s hot by a baseball.

The behaviorist wants to understand mental states in the exact same way. That is, the behaviorist thinks that mental states are particular ways people tend to behave in particular circumstances. So, take pain for example. Pain, behaviorist says, is the tendency to yelp and grab your arm whenever the right stimulus is present in the environment. So, whenever I’m stuck with a needle at the doctor’s office, I’ll yelp and grab my arm, at least if I’m going to count as having pain. Or to be in fear is just to tremble, have an increased heart rate, and engaged in fleeing behavior upon the presence of a fear inducing stimulus. Crucially, the behaviorist doesn’t want to say that to have a particular mental state is always to behave in a single way. For instance, you might yelp in response to some pains, but you might only wince in response to others. The behaviorist is happy with this. All they want to claim is that every instance of pain will be identifiable with some behavioral dispositions.

The behaviorist is attempting to solve the mind-body problem by suggesting that mental states are dispositional properties of the body and thus are ultimately physical. So, they accept a materialist ontology (although you might be able to be a behaviorist and accept a dualist or possibly an idealist ontology). Crucially thought, they want to do this in a different way than the physicalist. While the physicalist locates mental states with brain states, the behaviorist identifies them with behavioral states. One of the reasons for doing this is that if you’re a physicalist, there’s no room to do psychology, at least not really. For the physicalist, all psychology becomes neuroscience. The behaviorist doesn’t want to reject that brains are important for our mental states. What they aim to do is leave room for a psychology that is not merely the study of the brain. We won’t talk about this here, but it’s an important goal of the behaviorist.

One last thing to keep in mind about the behaviorist project. You might feel uncomfortable about the behaviorist attempting to identify mental states not with internal events, but with external behaviors. After all, when we are in a particular mental state, doesn’t it feel a particular way to be in that state? Fear isn’t just a tendency to behave in some way, there’s something it feels like to be afraid. The behaviorist doesn’t want to deny the importance of feelings for our mental states, but they want to understand those feelings differently. Another word that psychologists sometimes use to talk about feelings is ‘affect’. The behaviorist wants to understand feelings as affects. What you feel when you’re afraid isn’t some internal feeling. Rather, you’re affected in a particular way. You feel motivated or compelled to move. This is how the behaviorist wants to understand feelings. The felt part of any given mental state is that we feel compelled to act in some way. To feel afraid is to be motivated to run away.

Now let’s consider two related problems for behaviorism. First, in describing any given dispositional property, what we aim to do is give clear causes for that dispositional property manifesting as well as give clear behavioral effects. Take fragility, for instance. I can give you a very simple definition of fragility. An object is fragile, if when it is struck by something solid, it shatters. That’s all there is to being fragile. But it’s not clear how I can give a similar analysis for mental states. Mental states are complex. There’s a wide variety of events that will cause any given mental state, and even more behaviors that result from those causes. So, the behaviorist runs into trouble of either having to give simple general descriptions of mental states that won’t capture the richness and complexity of those states, or they have to give tens if not hundreds of of descriptions of any particular mental state to capture the variety of ways in which we might feel pain. But if they go in for the second option, the descriptions run the risk of being so specific as to not really give a description of what the general mental state is. For instance, if I give you one hundred different descriptions of one hundred different instances of pain, it’s not clear that I’ve given you a description of what pain is. I’ve just pointed out examples of pain.

Related to this worry is that for the behaviorist project to be successful, I need to give you a description of mental states that is explained fully by the behavioral responses. Importantly, in giving the description of a mental state, I cannot appeal to any other mental states.But consider this example. Let’s say you hit me in the arm, and I cry out in pain. But secretly, your hitting me in the arm didn’t cause any pain at all. I’m lying. In giving a dispositional description of pain then I need to say something like, a person is in pain if upon being it in the arm they cry out in pain and they aren’t lying. But lying is or involves mental states. To lie is to say something that you believe to be false. So, I can’t include that in my description. I need to figure out a way to explain lying in dispositional terms. And then I can include it in my description of pain. But it’s not obvious how I can explain lying in dispositional terms without including in my description some mental states. The problem here is that there is that no matter how hard we try, explaining mental states without appealing to other mental states cannot be done.

So, now that we have our critiques of behaviorism, we can move on to our final view: functionalism.

Functionalism

The final view we’re going to consider is functionalism. Functionalism is a theory that posits mental states are defined by their functional roles rather than by their physical makeup. According to functionalism, what matters about a mental state is not the internal substance or material that constitutes it but rather the role it plays in the cognitive system. This view allows for a more flexible understanding of mental states, accommodating a variety of physical implementations.

At the core of functionalism is the idea that mental states are like software states in a computer. Just as a computer program can run on different hardware systems while maintaining the same functional role, mental states can be realized by different physical substrates as long as they fulfill the same functional criteria. For example, the mental state of pain is characterized by its functional role in producing certain behaviors like wincing or yelping and in generating particular experiences, rather than by a specific type of neural activity or physical substance.

You might notice the similarity between functionalism and behaviorism. Both the behaviorist and the functionalist note the importance of behavior for understanding mental states. But whereas the behaviorist thinks a mental state can be fully explained in terms of behavior, the functionalist thinks the behavior is merely the output of some internal process. So, what’s the mental state for the functionalist? It should be thought of as a kind of program or set of rules.

Conclusion

Now that we’ve looked at questions concerning the mind, it’s important to keep in mind how philosophers engage in the project of talking about and explaining the mind. First, at one level the question about the nature of the mind is just an instance of a deeper philosophical question, namely what kinds of things ultimately exist. As we saw in considering our first three views about the mind (physicalism, dualism, and idealism), the view of the mind is grounded in a particular answer to the question of what exists. It’s important when thinking through philosophical questions to understand the implications of the view that you accept. If you accept a dualist ontology, that might lead you to accepting a dualist picture of the mind. And it’s important to know how your commitment to certain claims constrains and determines what you can say about other topics.

Second, it talking about the mind, there’s a lot of things that we care about. Behavior is important, but so is the intentional and linguistic nature of though—that our mental states are about something. [This is from the functionalism section] We also care about the fact that the brain does play an important role in our psychology, while at the same time recognizing that there’s something more than mere neural processes involved in our mental states. And each of the views that we discussed highlighted one or more of those important features. But it’s important when talking about the mind, we need to take all of those things into account. Now, you should be ready to do that.

Comprehension Questions

1. We talked about five positions one might have with respect to the question of the nature of the mind. First, rank them in order of plausibility. Then, briefly (in only 3-5 sentences for each view) explain why you find those views plausible or implausible.
2. Pick the view you ranked in positions two-four question 1. And in more detail explain why you ranked those in the middle spots. Then compare the views. Why do you find one of them more plausible than the others? How much more plausible do you find that view than the others? Is there anything that could be added to the position or removed from the positions you ranked in the third or fourth spots that could make it more plausible than the position you ranked second most plausible. Explain your reasoning.
3. Physicalism, dualism, and idealism all correspond to a specific ontology. In explaining behaviorism and functionalism it was suggested that they too correspond to a materialist ontology. But this need not be the case. Pick either behaviorism or functionalism and explain how you think the view might work with a dualist or idealist ontology. In doing so, be sure to note whether you find the new version of the view more plausible than the version discussed in the chapter.

Reading Suggestions

Primary Sources

Descartes, René, Meditations on First Philosophy

Locke, John, Essay Concerning Human Understanding

Hume, David, An Enquiry Concerning Human Understanding