The New Science of the Mind Page 2
To this end, this book aims to identify, clarify, render consistent, and, where appropriate, defend the central concepts on which a non-Cartesian cognitive science is to be based. This process begins in chapter 3. There, we shall examine the ideas of embodiment, embeddedness, enactedness, and extendedness with a view to identifying the content of each ideawhat it actually says or claims. Then we shall examine the ways in which each idea fits together with the others and the ways in which it does not. That is, we are going to look at the extent to which each idea either entails the others, or is compatible with the others, or is incompatible with the others. In the process, choices will have to be made. Perhaps one idea will simply turn out to be a version of another. In this case, our non-Cartesian cognitive science may turn out to be 3e (or even less), rather than 4e. More worryingly, perhaps one idea will prove incompatible with one or more of the others. Then, it seems, one of the ideas will have to go, and our task is to work out which one, and how to do justice to the overall framework of the non-Cartesian conception of the mind given these constraints.5
Once the process of identification, clarification, and rendering consistent has been completed, we get to the most important part of the project: defending the new, non-Cartesian, conception of the mind.' In a work of philosophy, this means defending the concepts out of which this new conception is going to be built-the concepts we have succeeded in identifying, clarifying, and rendering consistent. This is the principal task of the book, and most of the book will be devoted to it. None of these tasks is particularly easy. Even if we are witnessing the birth of a new science of the mind, some births are protracted and painful. Nonetheless, this book contends that all these tasks can be successfully completed.
Before we get to them, however, there are a few more preliminary matters that need our attention. The idea that the mind is not "in the head"-that the mind can extend out into the body and even into the world-will strike many as a truly crazy idea that no one who is even remotely sane could ever accept. In the rest of this chapter, I want to sketch, in a preliminary way, the general motivation for thinking that this idea is not as crazy as it seems.
2 Minds and Mental Phenomena
The new way of thinking about the mind is sometimes characterized as the claim that the mind, or even the self, is outside the head. Now that, at least on one way of thinking about the mind or self, would be a truly crazy claim. Happily, no version of non-Cartesian cognitive science commits us to this. That is, none of the various strands that make up 4e-the theses of embodiment, embeddedness, enactedness, and extendedness-should be interpreted as saying anything at all about the mind (and a fortiori, the self)-unless you want to think of this as a construction out of mental states and processes. What a non-Cartesian cognitive science is actually concerned with is mental states and processes, and not whatever it is that has them.'
Where does your mind begin, and where does it end? This is an unusual question. The usual question, at least if the history of philosophy and psychology is anything to go by, is: what is the mind? And the usual answer is: the brain. If this is right, then your mind begins and ends where your brain begins and ends-for your mind is simply your brain and nothing else. But where does your brain begin and end? People who think that the mind is the brain typically draw a firm distinction between the central and peripheral nervous systems. The brain is the lump of gray, gooey matter located in your head, made up of brain stem, hippocampus, and cerebral cortex. And if that is what the brain is, then that is what the mind is. Or more accurately, your mind is part of this triune structure, the part that is responsible for your being able to think and feel, and so on: your mind is (parts of) your cerebral cortex and hippocampus.
This idea is probably still unacceptably vague. But the most serious problem is with it is this: between you and me, I'm not sure I even have a mind-if this is understood as something different from my mental states and processes. This point, or at least something recognizably similar to it, was made a long ago by the philosopher David Hume:
Whenever I enter most intimately into what I call myself I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never catch myself at any time without a perception and never can observe anything but the perception.... If anyone upon serious and unprejudiced reflection thinks he has a different notion of himself, I must confess I can reason no longer with him. All I can allow him is that he may well be in the right as well as I, and that we are essentially different in this particular. He may, perhaps, perceive something simple and continued, which he calls himself though I am certain there is no such principle in me. (1739/1975: 252)
Hume's remarks, here, are addressed to the existence of what he calls the self. It is not clear that the self and the mind are the same thing for Hume.' For our purposes, however, this does not matter. We can make a precisely parallel point about the mind. When I enter, as Hume put it, "most intimately into what I call myself"-that is, when I turn my attention inward or introspect-I never encounter my mind: all I ever come across are mental states and processes. That is, when I introspect, I might become aware of what it is I am thinking, what it is I am feeling, and so on. I might become aware of my beliefs, my desires, my sensations, my emotions; my hopes, fears, aspirations, and anticipations. But what I never come across is the subject of these states and processes, at least if this is understood as something different from these states and processes. I never come across my mind thought of as something lying behind these states and processes.
We must be careful here, because we can easily transform this Humeaninspired observation into a very bad argument. Suppose I am looking at something-say, the can of diet Coke that invariably sits next to my laptop when I work, bearer of the psychotropic substance that I need to give my aged and rather reticent brain the morning kick start it needs. I can see the shape of the can, and its shiny silver surface. I can see the writing on that surface in black and red. But do I ever see the can itself? Well, what I don't see is the can as something separate from, or over and above, these properties. I don't see the shape, the surface, the adornment, and then, in addition, see the can. But does this mean I don't see the can? That would be the bad argument advertised at the beginning of this paragraph. I see the can in virtue of seeing the shape, surface, and adornment. In general, we see objects by way of, or in virtue of, seeing their properties.
That is the best way of understanding this Humean-inspired observation. I am not claiming that when you introspect you don't ever encounter your mind. Rather, I am making a point about what it is to introspectively encounter your own mind: to encounter your mind is to encounter your mental states and processes. You are aware of your mind in virtue of being aware of your mental states and processes, just as you are aware of the can of diet Coke in virtue of being aware of the shape, surface, and adornment of the can.
Nevertheless, lack of subtlety often has a habit of creeping back into our thinking. Often, when we think of the mind we have an idea of something that underlies all our mental states and processes: something to which those states and processes attach-something that holds them all together. Similarly, when we think of the can, we typically think of it as something that underlies its various properties-as something to which those properties attach. To avoid this questionable way of thinking about the mind-the mind as a bare substratum-I am, in the rest of the book, going to do my best not to talk about the mind at all (unless I am talking about someone else who is talking about the mind in this sense). I am only going to be concerned with mental states and processes: mental phenomena broadly construed. The non-Cartesian conception of the mind defended in this book is not, in fact, a conception of the mind at all-not if we understand this as something underlying mental states and processes. It is a conception of mental phenomena: it claims that at least some mental phenomena are either embodied, embedded, enacted, or extended. In this, it rejects the conception of mental phenomena embodied in Cartesian co
gnitive science: mental states and processes begin and end with the brain, because mental states and processes are identical with, or exclusively realized by, brain states and processes.
The view that mental states and processes are identical with, or exclusively realized by, brain states and processes is not a peculiar eruption of contemporary thought. On the contrary, it derives from a view of the mind that emerged in seventeenth-century France.
3 Descartes's Ghosts
It is easy to understand why the ideas of identity of mental and neural tokens combined with exclusive realization of mental types by neural types assumed such position of dominance in scientific thinking about the mind. To deny it seemed, at least at first glance, to commit you to an untenable position: to a form of dualism about the mind. Dualism received its most famous development at the hands of the philosopher, mathematician, and sometime mercenary Rene Descartes.
According to Descartes, the mind is a nonphysical substance. Today, we tend to use the word "substance" to mean something like "the stuff from which a thing is made." However, Descartes inherited his use of this term from medieval philosophers, and, for them, "substance" meant "thing" or "object." So the mind, according to Descartes, is a nonphysical object. In some respects, Descartes thought of the mind as similar to other bodily organs. The heart, liver, kidneys, and so on, are all objects found in the body and, more importantly, they are objects of a certain sort: ones defined by their function or what they are supposed to do. The function of the heart is to pump blood around the body; the function of the liver is to regulate metabolism; the function of the kidneys is to process waste products; and so on.
According to Descartes, the mind, like other things found inside the body, is defined by its function: and its function is to think. However, he argued that there is a crucial difference between the mind and all other organs found inside the body: the mind is a nonphysical substance. By this, he meant, fundamentally, that the mind is nonspatial. Physical things, Descartes claimed, have a single defining feature: extension. By this he meant that physical things occupy space or take up room. This, he thought, is precisely what makes them physical things. Therefore, the mind, being nonphysical, must also be nonspatial.
However, there are actually two different aspects of the idea of space, and Descartes never clearly distinguished between them. On the one hand, there is spatial extension-taking up room. On the other hand, there is spatial location-existing at a particular place. If an object has spatial extension then it must also have spatial location. It is not possible for an object to occupy space without the space that it occupies being somewhere or other (even if this "somewhere or other" is rather vague). But just because an object has spatial location, it does not necessarily follow that it has spatial extension. For example, scientists are willing to countenance (and some even insist on) the existence of point particles: particles that exist at some particular place but do not take up any room. Even if they ultimately turn out to be wrong, their willingness to countenance the possibility shows, at least prima facie, that the ideas or concepts of spatial extension and spatial location are not the same. The idea of spatial extension seems to entail the idea of spatial location. But the idea of spatial location does not entail the idea of spatial extension.
Although Descartes never clearly distinguished between the ideas of spatial extension and spatial location, this distinction can be used to make sense of Descartes's position.' In effect, Descartes's view was that minds do not have spatial extension-this is what makes them nonphysical-but they do have spatial location. Every mind is located inside a (functioning) brain, and every (functioning) brain is located inside a body. Descartes was never exactly clear on the precise location of the mind; but somewhere in the vicinity of the brain's pineal gland seemed to be his favored hypothesis."
Descartes's view is known as dualism-since it asserts that each one of us is composed of two different kinds of thing: physical bodies and nonphysical minds. Despite making something of a recent, limited comeback (e.g., Chalmers 1996), dualism is still almost certainly one of the most reviled philosophical views ever invented. Generations of professional philosophers have spent much time and energy (a) showing that Descartes's arguments for dualism don't work, (b) arguing that dualism itself has empirical and conceptual difficulties so serious as to render it an effectively untenable position, and (c) inventing catchy slurs with which to disparage his view-most famous of which is, perhaps, Gilbert Ryle's (1949) dismissal of the view as the dogma of the ghost in the machine. Today, even the word "Cartesian" is often used as a term of abuse.
The popularity of the mind-brain identity/exclusive neural realization combination stemmed, in large part, from the belief that to deny it was to be committed to dualism of a broadly Cartesian sort. This, we are now beginning to understand, is not true. Indeed, what has been overlooked until very recently is just how much the mind-brain identity theory/ exclusive neural realization combination has inherited from Descartes: they are, in effect, fashioned in the image of the Cartesian conception of the mind.
The Cartesian conception of the mind in fact has two distinguishable aspects. First, there is the claim that the mind is a nonphysical thing. Second, however, there is the idea that the mind is something that exists inside the head. So, when Ryle dismissed Descartes's view as the myth of the ghost in the machine, this dismissal actually has two distinguishable aspects. First, Ryle was rejecting the idea that the mind is a ghost-that is, a nonphysical thing. But second, and for our purposes more significantly, he was rejecting the idea that the mind is the sort of thing that can be found inside the bodily machine. If you reject only the first idea, then you have not fully rejected the Cartesian conception of the mind, but only part of it. And that, in effect, is precisely what the mind-brain identity/exclusive neural realization combination did. It rejected Descartes's idea that the mind is ghostly or nonphysical, but it left intact the second defining idea of the Cartesian conception: the idea that the mind is something that exists inside the head. In other words, the mind-brain identity/exclusive neural realization model is a view fashioned partly, but as things turned out, decisively in the image of the Cartesian view of the mind.
Non-Cartesian cognitive science is based on a more complete rejection of the Cartesian view of the mind. This science is, of course, materialistic: there will be no reversion to nonphysical substances-that particular Cartesian ghost remains well and truly exorcised. However, non-Cartesian cognitive science also rejects, or is at least thought of as rejecting, Descartes's second idea, the idea inherited by the mind-brain identity/ exclusive neural realization model. That is, it rejects the claim that mental states and processes occur purely inside the brains. Some of them do; but not all of them do. Mental states and processes are not just things that happen inside our brains; they are also things that happen, partly, in our bodies and even, partly, in the world outside of our bodies. The qualification "partly" is (i) obvious, (ii) crucial, and (iii) ignored with surprising frequency. With (iii) in mind, let me risk being tediously overemphatic. No one is going to claim that there can be free-floating mental processes hovering around in the world outside the head. That would be an example of a truly crazy idea that no remotely sane person would want to hold. Almost as insane would be the idea that there can be mental processes that are entirely made up of processes occurring inside the body but outside the brain. No one wants to maintain that either. The idea, rather, is that in the case of some mental processes but not all, part of that mental process-but never all-is made up of factors that occur outside the brain of the subject.
Our next obvious question is: why think this?
4 Best Friends and Barking Dogs
The starting point for non-Cartesian cognitive science is the extent to which we make use of things around us in order to solve problems and get things done. Our tendency to do so has become more and more obvious in recent years. Consider, for example, a relatively new acquaintance of mine: my car's GPS (global positioning s
ystem). Actually remembering how to get to a destination: that was so 2007 (or, for more those of a less technophobic persuasion than I, so 2005). In 2009, my GPS will tell me how to get anywhere I want to go. "Make a safe and legal U-turn," the reassuring, and apparently vaguely stoned, voice tells me. OK, will doll
The knowledge afforded me by my GPS is essentially situated. That is, it provides me with practical and easily digestible instructions because it uses my physical location to encode at least some of the information I require to follow those instructions. The information with which my GPS provides me is, in this sense, indexical: it has a meaning that is partly made up of is made up of the meaning of words such as "here," "there," "this," "that," and associated locutions. Because of this the instructions, we might put it, show more than they say. If the instruction is "make a safe and legal U-turn": then that is precisely what the instruction says. But what it shows is that you should make the U-turn at the next intersection-which is "there," in front of you.12 The instructions show more than they say because part of their informational content-part of their meaning, broadly construed-is encoded in my physical location at the time the instructions are given.
Think about the difference between my GPS and its precursor: MapQuest. For our purposes, both the similarities and differences between the GPS and MapQuest are important. Consider, first, the similarities. Both the GPS and MapQuest are external forms of information storage-external to my body. I don't need to remember how to get somewhere, because the information about how to get there is contained in both the GPS and in MapQuest. These external forms of information storage, therefore, reduce the burden on my biological memory. Memory tasks that I would find difficult are offloaded onto the environment.