More on Zombies

In my last post I discussed David Chalmer’s idea of philosophical zombies – hypothetical creatures whose brains have precisely the same physical structures as ours and function in the same ways that our brains do, but without consciousness. Several people who read early drafts of my book, Your Living Mind, dismissed zombies as irrelevant. The whole idea is moot, one of them remarked, since it would be impossible for us to know that such a creature is a zombie. (Maybe the person sitting right next to you is one of them!) But Chalmers’ scenario is an example of both the value and the subtlety of thought experiments. If there actually could be such creatures, then conscious experiences are not brain events.

The zombie story asserts that if there could be a creature that is physically identical to you, but not conscious, then consciousness is not a state of your brain. We could dispute this claim by arguing that even though a creature physically identical to you could exist without being conscious, nevertheless consciousness is a state of your brain. But that won’t work. Let’s call your current brain state CBS. If your brain’s being in state CBS is sufficient for your being conscious, then if some other brain is in CBS, it would also have to be conscious. So you could not have a physically identical zombie twin. (What a relief!) On the other hand, if a brain’s being in state CBS is not sufficient for its being conscious, then consciousness is not a brain state. We would need a brain state plus something else to have consciousness – or we would just need the “something else.” So if zombies are truly possible, qualia are not brain states. Since there has been a strong trend toward saying that all real things are, in some sense, physical, that would be a revolutionary finding.

Michael Tye clarifies Chalmers’ idea with an omnipotent-being scenario. “One way to picture what is being claimed here is to imagine God laying out all the microphysical phenomena throughout the universe. Having done so, and having settled all the microphysical properties of those phenomena along with the basic microphysical laws, God did not then have to ask Himself ‘Shall I make lightning flashes or caterpillars or mountains … ?’ No further work was needed on His part.” Why? Because a lightning flash simply is a group of microphysical entities operating according to certain laws. By making all these particles and deciding how they would interact, the Creator would have ensured that lightning flashes, caterpillars, etc. would exist.

But what if consciousness is not physical? In that case zombies are possible. “Even if God had no further work to do in determining whether there would be a tree in place p or a river in place q or a neuron-firing in place r, say, having settled all the microphysical facts, God did have more work to do to guarantee that we were not zombies.”*

Tye is not trying to show that a deity created consciousness. That’s not the point. He’s just noting that this is one way of understanding Chalmers’ scenario. Conceivably, then, there could be an exact physical duplicate of you, right down to the last whirling electron, that does not enjoy a single millisecond of conscious experience.

Chalmers emphasizes that he is not trying to prove that a zombie duplicate of you or me could really exist in this universe – only that this sort of thing is conceivable. But what does “conceivable” mean? Now the fog drifts in. There are several types of conceivability, including a contentious notion called “ideal conceivability.” Philosophical professionals have not yet sorted out these intricacies.

In trying to solve the hardest problems of consciousness we seem to be perpetually stuck at square one. Nagel has stated bluntly that “we have at present no conception of what an explanation of the physical nature of a mental phenomenon would be. Without consciousness the mind-body problem would be much less interesting. With consciousness it seems hopeless.”** And William Seager concludes his book, Theories of Consciousness, with this dispirited admission: “It is indecent to have a ragged and unpatchable hole in our picture of the world. Cold comfort to end with the tautology that an unpatchable hole is … unpatchable.”***

To some it seems as if these scholars are worrying about trivialities, as irrelevant as asking how many angels can dance on the head of a pin. But some questions about the nature of reality actually are quite difficult. I have my own ideas about how to understand consciousness, but on some level I must also bow to this great mystery.

Roger Christan Schriner

*Michael Tye (2009) Consciousness Revisited: Materialism without Phenomenal Concepts. (Cambridge, MA: The MIT Press), pp. 25-26.

**Thomas Nagel (1974) “What Is It Like to Be a Bat?” Philosophical Review, October, 1984, Vol. 83, No. 4, p. 436.

***William Seager (1999) Theories of Consciousness: an Introduction and Assessment. (New York: Routledge), p. 252. Ellipses are in the original text.


What Is It Like to Be a Bat? More on Nagel’s Famous Conundrum

In my previous posting I quoted Thomas Nagel’s famous essay, “What Is It Like to Be a Bat?” Nagel suggested that it is “like something” to be conscious. It is like something, for example, to be a bat. It is like something else to be you, reading these words right now. It is like something to be tasting guacamole. It is like something else to feel nauseous (unless it was really bad guacamole).

And so on. By contrast, most of us assume there is nothing it is like to be a light bulb or a toadstool. They are not conscious, so it is like nothing at all to be them. (Some would argue that the toadstool is sentient, and of course panpsychists would argue that even the light bulb is conscious.)

In time “a consensus … emerged that Thomas Nagel’s expression, ‘what it is like to be’ succeeds in capturing well what is at stake” in discussions about consciousness” (Varela and Shear, Journal of Consciousness Studies, February/March, 1999, p. 3). But even though it was a stunning intuitive breakthrough, some people doubt that it has any clear meaning. David Rosenthal complains that the term “‘what it’s like’ is not reliable common currency” and quotes William Lycan as saying that this phrase is “positively pernicious and harmful” (Rosenthal, Analysis, July, 2011, p. 434).

Here’s an example of the way this phrase can confuse us. Some say that what-it’s-like includes only sensory experiences, such as seeing the blueness of the sky, hearing a harpsichord, or suffering a migraine headache. Others say that non-sensory mental states such as highly abstract thoughts can be “like something.” As Rocco Gennaro writes, “It does indeed seem right to hold that there is something it is like to think that rabbits have tails, believe that ten plus ten equals twenty, or have a desire for some Indian food” (The Consciousness Paradox, p. 27). It’s not easy to adjudicate this dispute.

Another problem is that this term allows us to fuse the subject of experience and the object of experience without realizing we’re doing that. If that sounds confusing, it probably means you’re paying attention. It is very difficult to think and communicate about this issue, but I’ll give it a go:

People sometimes use “what it’s like” to refer to what it is that we are experiencing – blueness, musical notes, pain, and so on. But others use what-it’s-like language to mean what it’s like to subjectively experience these things – what experiences are like for the creature that has those experiences.

This reflects a duality in the way we think about consciousness. Sensory experiences seem to be both what we experience and the way these experiences seem to us. They are a certain way, and they seem a certain way. There is a subtle but crucial difference between the sense that you are experiencing something and the sense that you are experiencing something.

I read Nagel himself as emphasizing the second interpretation. He didn’t talk about what a bat’s echolocation patterns are like. He talked about what it was like to BE the bat, sensing via echolocation. But many philosophers who speak of what-it’s-like emphasize the first interpretation – what the mental states that we are experiencing are “really like.”

I’ll mention just one reason this distinction is important. Theoretically, what we are experiencing and what it’s like for us to experience it could come apart. Suppose pain is a brain state that is sometimes conscious and sometimes unconscious, as when a headache drifts in and out of my awareness. And suppose the experiencing self is a (very complex) brain state that detects and responds to sensory inputs. In principle, my brain could malfunction so that when the experiencing self detects a pain state, it operates as if it was enjoying the experience of tasting peanut butter. In that case, what am I really experiencing, pain or peanut-flavor? (For a spirited argument about this point see the articles by Block, Rosenthal, and Weisberg in Analysis, July, 2011.)

So when people talk about what it’s like to have conscious experiences, this implies both the experience that we’re aware of and what it’s like to be aware of this experience. It fuses the object of experience with the subject of experience. Discussing what-it’s-like makes it sound as if we’re dealing with one idea, but it’s actually an amalgamation of two ideas. This causes confusion.

And speaking of confusion, I’d appreciate feedback about which aspects of this blog-post are unclear to readers. I’m trying to refine my presentation of this murky topic.

In Your Living Mind I wrote: “We seem to have needed such a term, but perhaps we will eventually find better ways to express what Nagel was getting at.” I still find myself using what-it’s-like language, but I try to make clear what this phrase means to me. To me, consciousness involves what experiences are like for the experiencing subject. This seems more in keeping with Nagel’s original intent.

Roger Christan Schriner

Six Persistent Enigmas about Consciousness

It seems obvious that consciousness is remarkable and mysterious, but we struggle to say just why it’s so special. In recent decades, however, several philosophers have managed to articulate some of the key features that make consciousness extraordinary. These new insights are intriguing, but they also make it hard to understand how consciousness could occur within a brain. In fact, some of them make it hard to understand how consciousness could occur at all, in any conceivable medium.

In the next few weeks I will explore some of these insights and conundrums. So here is the first of six persistent enigmas about consciousness:

In 1974 Thomas Nagel challenged behaviorism with an essay called “What Is It Like to Be a Bat?” (Philosophical Review, October, 1984, pp. 435-50). According to behaviorists, if we want to learn about bats, we study the way bats behave. But what about knowing how it is to be the bat itself?

Nagel used bats as his example because they use an exotic navigation system called echolocation. They send out high-frequency shrieks and monitor the way these sounds are echoed back. Since we do not typically navigate in this way, we have a hard time guessing what it is like to have this sensory ability.

But Nagel wasn’t really talking about bats. He was using echolocation as a dramatic example. His real point is that for every conscious organism there is something it is like to be that organism. It is this what-it’s-like aspect of experience that is left out by behaviorism – and, some would say, by science itself.

If I knew everything that could possibly be known about you except what it’s like to be you, would my knowledge of you be complete?

Nagel drove home his point by writing that “to form a conception of what it is like to be a bat … one must take up the bat’s point of view” (p. 442). But if we can only understand an organism’s experience from its special vantage point, how can science ever understand consciousness? Science strives for objectivity, and Nagel declares that “any shift to greater objectivity – that is, less attachment to a specific viewpoint – does not take us nearer to the real nature of the phenomenon: it takes us farther away from it” (p. 445).

Nagel’s essay was only 15 pages long, but it has had an enormous impact. The phrase “what it’s like” now permeates consciousness literature. Some think this is an unfortunate development, and in my next entry I’ll consider the strengths and weaknesses of this revolutionary piece of scholarship.

Roger Christan Schriner

Opening a Window into Philosophy of Mind

No doubt there are still cocktail-party conversations about Descartes, Nietzsche, and Sartre, but I wonder how many Bordeaux-sipping intellectuals discuss Dretske, Nagel, and Kripke. The relationship between academic philosophy and the general public is nearly non-existent. Professors mostly speak to each other, in a technical language full of confusing terms with multiple definitions – “qualia,” “intentionality,” “representationalism,” “epiphenomenalism,” and so on. A few, such as Daniel Dennett and Nicholas Humphrey, have written for a wider audience, but most seem comfortable remaining within their own ivory towers.

I have been a member of the American Philosophical Association for nearly 25 years, reading books and professional journals and regularly attending conferences and colloquia. So I have spent years as the proverbial fly on the wall, listening to professorial interchanges within these lofty retreats. I am impressed with the need for competent philosophical analysis, and one of my life goals is to open a window into contemporary philosophy of mind for interested non-philosophers.

But I have sincerely wondered whether this is possible. When I tell people about my book, Your Living Mind: The Mystery of Consciousness and Why It Matters to You, I cannot sum it up in a sound bite. In the book itself, it takes the Introduction and the first five chapters just to explain the key problems.

Last Sunday, however, I had a very encouraging experience. I presented Part One of a workshop called Your Mysterious Mind: New Insights into Baffling Enigmas at the Unitarian Universalist Church of Palo Alto. The program concludes with Part Two on February 15. About 35 showed up, an excellent turnout for an early Sunday afternoon program, and participants seemed interested and engaged.

It was especially heartening to see that some attendees had an intuitive feel for the problem of consciousness and its possible solutions. One person (“K”) dealt with Frank Jackson’s Mary-scenario by proposing what academicians call the ability hypothesis – after seeing colors for the first time, Mary acquires new abilities but does not acquire new facts. “M” suggested that sensory experiences are memories, perhaps implying that they involve cognitive responses to recent (not current) perceptual inputs. And “E,” who has a strong science background, wondered whether some consciousness-conundrums are merely pseudo-problems. I could imagine Daniel Dennett cheering her on: “Right! There isn’t any special Problem of Consciousness. There just seems to be.”

I’m under no illusions that conveying contemporary philosophy of mind will be easy, but I am now more hopeful that my project will make a positive difference.

Roger Christan Schriner