Consciousness

Josh Weisberg

• Publisher: Polity
• Year: 2014
• Print ISBN: 9780745653457, 9780745653440
• eBook ISBN: 9780745686639
• Edition: 1
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

Each of us, right now, is having a unique conscious experience. Nothing is more basic to our lives as thinking beings and nothing, it seems, is better known to us. But the ever-expanding reach of natural science suggests that everything in our world is ultimately physical. The challenge of fitting consciousness into our modern scientific worldview, of taking the subjective "feel" of conscious experience and showing that it is just neural activity in the brain, is among the most intriguing explanatory problems of our times.

In this book, Josh Weisberg presents the range of contemporary responses to the philosophical problem of consciousness. The basic philosophical tools of the trade are introduced, including thought experiments featuring Mary the color-deprived super scientist and fearsome philosophical "zombies". The book then systematically considers the space of philosophical theories of consciousness. Dualist and other "non-reductive" accounts of consciousness hold that we must expand our basic physical ontology to include the intrinsic features of consciousness. Functionalist and identity theories, by contrast, hold that with the right philosophical stage-setting, we can fit consciousness into the standard scientific picture. And "mysterians" hold that any solution to the problem is beyond such small-minded creatures as us.

Throughout the book, the complexity of current debates on consciousness is handled in a clear and concise way, providing the reader with a fine introductory guide to the rich philosophical terrain. The work makes an excellent entry point to one of the most exciting areas of study in philosophy and science today.

1

The Problem

What is the problem of consciousness? If there's one most pressing worry about consciousness in contemporary philosophy, it's what philosopher David Chalmers calls “the hard problem” (Chalmers 1996). It's the problem of explaining why anything physical is conscious at all. More specifically, why do certain physical brain processes result in the subjective experience of color, rather than experiences of sound or no experiences whatsoever? The problem is a version of an older philosophical conundrum, the so-called “mind–body problem,” famous from the work of René Descartes. The hard problem of consciousness is where much of the fighting over the mind–body problem ends up after the rise of modern psychology, cognitive science, and neuroscience. Consciousness seems to be the remaining bit that fails to fit nicely into the modern scientific worldview. Even after we've explained all of what the brain does, down to the finest neural detail, the hard problem of consciousness appears unanswered. The hard problem, and philosophers' attempts to deal with it, is the main focus of this book.

But what is consciousness? As with many philosophical questions, even agreeing on the thing we disagree about is difficult! How we pick out consciousness in the first place can have big implications for how hard the hard problem appears. If we define consciousness as “the mysterious, unknowable core of human experience,” then it's not surprising that consciousness seems inexplicable. But if we define consciousness as “whatever causes our verbal reports about how we feel,” then we may be defining a real mystery out of existence at the get-go. So it would be nice if we can find a way to characterize consciousness that neither builds in unsolvable mystery, nor rules it out by stacking the explanatory deck. While there isn't a single agreed-upon definition in contemporary philosophy, unfortunately, we can focus on a set of puzzling “thought experiments” – imagined scenarios where innocent-looking steps lead us to philosophical worries – to zero in on what's at issue. And while not every philosopher agrees that the thought experiments carry great meaning, all can agree that something must be said to explain the puzzlement they generate. What's more, much of the contemporary literature on the philosophical problem of consciousness at least touches on some or all of these imagined scenarios, so they are needed background knowledge for anyone wanting to go down this particular rabbit hole.

The Knowledge Argument

The first thought experiment is called the “knowledge argument” against physicalism (Jackson 1982). Physicalism is the claim that everything is ultimately made of physical stuff like atoms and nothing else. Physicalism is a central feature of the standard scientific worldview of today. The knowledge argument seems to show that consciousness cannot fit into that worldview. The thought experiment brings out an everyday intuition that many of us have before we get near a philosophy classroom. Intuitions are generally unarticulated beliefs or gut feelings we have about certain subjects. For example, most people feel it's wrong to kick a puppy, even if we can't really justify why that is. A key job of philosophy is exposing these underlying intuitions and investigating whether they're to be kept or thrown out as we develop a deeper understanding of a subject. The everyday intuition brought out by the knowledge argument is the idea that a person blind from birth will never really know all that sighted folk know about colors. A blind person might ask us to describe red. We can say things like “it's a feature of objects which can vary independently of shape.” The blind person might say, “Oh, you mean like texture!” But we'd have to say that's not it. We might say, “Red is hot, like the sound of a trumpet.” But we'd quickly recognize that there's something we can't put into informative words, something that's left out of any description we offer to our blind friend. That left-out something, whatever it is, is a key element in the problem of consciousness.¹

The knowledge argument takes this intuition and makes a more general point about the limits of physicalism and the scientific worldview. Instead of imagining (or actually talking to!) a blind person, we are asked to imagine a super-scientist of the future. She lives in a time when all the outstanding problems of science have been solved. What's more, she has a prodigious memory and an unfailing ability to digest and understand science. In fact, she has gone through all the relevant material and knows all of the facts of a completed science. But this super-scientist – let's call her Mary, following Frank Jackson who introduced this story in 1982 – has been brought up in a very special environment. Everything in her world is black and white and shades of grey (perhaps this is achieved by fitting her with special lenses which make the world look like it does on a black-and-white TV set). She has never in her life seen colors. Now for the crucial intuition-tapping question: when she's finally released from her black-and-white captivity and sees a red rose for the first time, does she learn anything new? Most of us would say that she does learn something new. She learns that this is what red looks like, that this is what it's like for one to see red. This seems like a fact she couldn't have known beforehand. But given that she already knew all of the facts of science, this must be a fact beyond the reach of science, something left out of science altogether! So there are facts beyond the scientific worldview. And since science plausibly contains all the facts about physical stuff – where all the atoms are, how they interact, and so on – this new fact must be about something that isn't physical. So physicalism, which claims that, ultimately, all the facts are physical facts, must be incorrect.

And what does this tell us about consciousness? When we think about it, the fact that Mary doesn't know before her release is a fact about her (and others') experience. It is a fact about what it's like to see red from the inside. She already knows all the “outside” facts about red: that it's feature of the surfaces of some physical objects, that such surfaces reflect light at certain wavelengths, and so on. She even knows, in neurological terms, what happens in normal observers when they see red: cone cells on their retinas fire in a particular ratio, activity occurs in area V4 of their brains, and so on. But none of these scientific facts helps her to know what it's like to experience red. That is a fact about conscious experience. There's a special quality there – the “redness” of red. Philosophers label these sorts of special qualities of consciousness “qualia.” Mary lacks knowledge of red qualia. And no amount of scientific information can give her that knowledge, or so it seems. There is clearly something special about conscious experience.

So are we any closer to figuring out just what the problem of consciousness is all about? From the knowledge argument, we can see that consciousness possesses special qualities, and these qualities seemingly defy description. If you haven't experienced them yourself, no amount of what philosopher David Lewis calls “book learning” will tell you (Lewis 1988). And as philosopher Ned Block says, channeling Louis Armstrong, “if you gotta ask, you're never gonna know!” (Block 1978). And if qualia can't be informatively described, then they can't be explained scientifically, or so it seems. We are left with a hard problem! Now, not all philosophers agree with this bleak assessment of consciousness, but it's hard to deny that there at least appears to be an explanatory puzzle here. Throughout this book, we'll consider a range of responses to the problem, from those who accept the knowledge argument and try to sketch out what must be added to our worldview to fit in consciousness, to those who argue that the argument is misleading, inconclusive, or completely invalid. Those theorists have to explain why it is that consciousness prima facie poses a problem and then explain where consciousness fits in the current physicalist worldview. But all that matters so far is that we begin to get a feel of the philosophical worry here. A second thought experiment may help to bring that worry out further.

Zombies!

This thought experiment asks us to imagine, if we can, a creature just like us in all physical respects, right down to the last atom, but lacking consciousness (Chalmers 1996). Could you, for example, have a perfect physical doppelgänger, a molecule-for-molecule twin, who nonetheless fails to be conscious? This sort of nonconscious physical twin is called a “zombie” by philosophers. Unlike the zombies in monster movies, these “philosophical zombies” look exactly like us from the outside. But inside “all is dark” – there is no experience at all. Consider that many of the tasks we perform repeatedly in a day can become automated, so that we can do them on “auto-pilot.” For example, if I have to wash the dishes (a task I perform many times a week at our house!), I may become so lost in philosophical or football-related thought that I lose focus on the dishes and may not even be aware at all that I've finished several plates and bowls. Might it be that a zombie does everything on autopilot? If such a creature is merely conceivable – if we can form a coherent mental picture of one – that may show that consciousness is something over and above a physical process. If consciousness were nothing more than a physical process, we shouldn't even be able to imagine zombies. Or so some philosophers argue.

Consider, by contrast, trying to conceive of something physically identical to a mountain, yet somehow not being a mountain. It's hard to even figure out what this means. That's because a mountain is nothing more than a huge pile of basic physical bits. If you have all those bits arranged in the right way, you've got a mountain. That's all there is to being a mountain. Because of this, philosophers say that mountains supervene on physical matter. Now back to our zombie twin. Unlike the mountain, it seems that we can at least imagine a creature just like us physically but lacking consciousness. It seems that the supervenience of consciousness on physical matter is not a straightforward affair. There seems to be at least a conceptual gap between consciousness and physical stuff, in contrast to the mountain case. To take another example, imagine a molecule-for-molecule physical duplicate of yourself, doing everything that you do, but not breathing. Or walking. Again, it seems impossible to imagine what's being asked. If a creature has all the molecules we do, and it's using them to exchange oxygen and carbon dioxide with the atmosphere, then it is breathing! That's all there is to it. Likewise, if a creature shares our molecular structure and is moving in a controlled way on two legs, it's walking. So breathing and walking supervene on our physical makeup and the action of our physical systems. But that's not obviously so for consciousness. It's not clear that all there is to consciousness is the performing of some action by a physical system. And that's the problem. What is consciousness if it's more than just something physical? Figuring out what consciousness is seems harder than figuring out what breathing is.

And again we can focus on just what's seems to be missing in the zombie case to try to pin down just what consciousness amounts to. When we engage in certain behaviors, it feels a certain way to us – there is something it's like to be us, for us, as we do these things.² Not so for our imagined zombie twins. This “feel,” this “something that it's like for us,” is the feature of the mind at issue in philosophical debates about consciousness. It's the way experience feels from the inside, for us, subjectively. And due to the apparent slippage between consciousness and physical stuff, we are faced with a puzzle. Given the success of physical science in explaining how we work, we might expect that everything about us is explainable in this way. But consciousness seems to buck the trend. It may well mark the limits of natural science. There may be a special inner core of the mind, a special property of experience, lying forever beyond the reach of scientific theory. This is the problem of consciousness.

The Long-Distance Driver

Yet another thought experiment, this one far closer to home, may help get at what's at issue. Rather than imagining super-scientists of the future or strange nonconscious doppelgängers, imagine (or recall, if you can) driving for a long spell down a stretch of relatively deserted highway (Armstrong 1981). If you're like me washing the dishes, you may have found that you've driven for some time while lost in thought. You then snap back to reality and focus again on the highway in front of you. While you were “out,” you didn't lose control of the car (hopefully!). That means you must have taken in visual information and used it to handle the car properly. But something was missing, something that clicked back on when you noticed the road again. That something is arguably conscious experience. It's what's lacking during the autopilot moments and what returns when you're aware of the road again. Now this thought experiment doesn't generate the puzzle the others do, but that may help us to be more clear about the subject matter here. Sometimes our mental states occur consciously, sometimes they don't. Now, what does that difference amount to? And can we explain the difference in brainy terms?

Androids

Yet another way to see the problem is to think about what we'd do if we ever met a really intelligent android. Imagine a spaceship brings a visitor from outer space to our world. It can speak our language, and we eagerly converse with this being. It tells us of its home far, far away, the trials and tribulations of spaceflight, the trouble with tribbles, and so forth. At this point, we'd probably all think such a creature must be conscious. But then imagine that we notice some wires poking out from its scalp and we ask it if it's an android. Yes, it says, and dramatically pulls off its faceplate, revealing a grid of sensors, lights, gears, and circuits! At this point, are we so sure that the being is conscious in the way we are? Many people become hesitant to attribute consciousness to such a creature, once they learn it's a robot. Why is this? Well, one aspect felt to be missing is inner feelings, the emotions and sensations we experience. An intelligent android might be able to reason and remember, perhaps even better than we do. But there seems to be an open question as to whether or not the creature is conscious.

We then might wonder if there's any further test we can do to the robot to determine once and for all if it's conscious. But what could we possibly do? We might kick it in the shins and see how it reacts. But what if it yells out and starts hopping around? Can we be sure that this is because it's in pain and not just because it's following a program of avoidance and evasion? Couldn't it just be “going through the motions”? So maybe we can try to observe its electronic “brain” in action when we kick it in the shins. But again, how would this help? No doubt we'd see all sorts of complex mechanical interactions. Circuits would allow energy to flow through various processors, analyzers would process data, and motor programs and reactions would be triggered. But is there anything there to tell us that those actions, no matter how complex, are conscious? That is, is there anything to tell us that there's subjective inner experience, replete with the “ouchy” quality of pain, going on? It seems like all could go on in the absence of consciousness. And even if consciousness is there, we don't seem to know how to detect it. As you can see, consciousness is becoming rather slippery!

And note that we'd have the same exact problem even if the visitor turned out to be fully organic and not an android at all. Imagine our visitor is filled with green goo. Could that tell us if it were conscious? How? Why is gooey organic material any better than non-gooey mechanical stuff? We seem to be in the same pickle. Even if the alien told us, in English, that it is in serious pain, that it hurts, how do we know that it's not just saying that because of some automatic, autopiloted response, one that occurs without the kind of inner quality we feel? At this point, you may be worried that we can't even tell if another human is conscious! And that is a worry, called by philosophers the problem of other minds. But, at least in our case, we can gain some traction by noting that we're all made of the same sort of stuff, that we have the same evolutionary backgrounds, that we have relevantly similar brain structures, and so on. But still, the very fact that this sort of worry is possible at all shows that there's something weird about consciousness. We know it intimately in our own case – what is better known to me than my conscious pains and pleasures? But we can only attempt to infer it in others, and it looks like a space opens up for us to be wrong about its presence. Now, this is nuts. Surely I can know that you're in pain when I kick you in the shins with my cowboy boots. So it seems, but we can feel the slippage here between conscious experience and other things we do, like breathing and walking. Some philosophers take this slippage to indicate a serious metaphysical rift in reality, a place where the normal physical rules break down. Others think that, despite first (or even second or third) appearances, consciousness in the end can be roped back into the corral of science. But it will take some doing, if it can be done at all.

A Few Disclaimers, Definitions and Distinctions

I hope that you have a bit of a feel for the problem of consciousness. We will need to become more precise as we go, but the best way to really grasp the key issues is to grapple with the pros and cons of various theories of consciousness offered by philosophers and scientists. This is the best way to learn about any complex and controversial subject: study the back-and-forth tennis match of ideas. It's hard to understand one theory without getting a good idea of its rivals, and it's hard to know what we really think if we don't understand views opposed to ours. This task will take up the rest of the book. We'll survey theories holding that consciousness is radically different from anything else in the universe and thus requires special metaphysical maneuvering to fit into our understanding. We'll look at views that see consciousness as just another problem for science to conquer without the need for major philosophical renovations. And we'll even look at views claiming that any deeper understanding of consciousness is beyond us. But first we need to lay out a few helpful ideas in order to make our journey more manageable. And we'll need to say a bit about what this book is not. That task will take up the rest of this chapter.

While this book deals with the most persistent and central philosophical worry about consciousness, it is distinctly a work of what is loosely known as “analytic philosophy,” the sort of philosophy focused deeply on issues of language and logic, an approach inspired by the work of Gottlob Frege, Bertrand Russell, Ludwig Wittgenstein, Rudolf Carnap, and others from the early and mid-part of the twentieth century. This approach, in its purest form, tries to first analyze our concepts, and then to see what those concepts, properly clarified, might...

Table of contents

• Cover
• Key Concepts in Philosophy
• Title page
• Copyright page
• Dedication
• Acknowledgments
• 1: The Problem
• 2: Mysterianism
• 3: Dualism
• 4: Nonreductive Views
• 5: The Identity Theory
• 6: Functionalism
• 7: First-Order Representationalism
• 8: Higher-Order Representationalism
• References
• Index