The role of consciousness

(First in a series. I'm going somewhere with this.)

Suppose two objects are placed before you. The one on the left is a can of Coca-Cola. The one on the right is completely identical to that can, right down to the subatomic level. Both cans have the same artwork, the same metallurgical composition, and the same opening mechanism. Inside, they contain the same quantities of the same ingredients. When you open them, they fizz in the same manner. When you drink them, they taste exactly the same. They are entirely identical and indistinguishable.

Well, not quite identical. You see, the can on the right isn't Coca-Cola at all. It's Zombie Coke. The pertinent difference is that while Coca-Cola has flavor, Zombie Coke does not. Certainly, Zombie Coke tastes the same as Coca-Cola, and gives every indication of having flavor. Nevertheless, it is completely devoid of flavor. (Bear with me; this is all about abstract concepts.)

What does this say about the attribute called "flavor" I've defined? First off, since there's no physical difference between Coca-Cola and Zombie Coke, flavor must be something non-physical—supernatural, you could say. It also has no effect on either soda, as they both taste the same. And because flavor has no effect, there's no way to observe it.

If you find all this confusing, or even dumb, don't worry (it's going to get a lot dumber!). Perhaps you're wondering, why would I even bother defining "flavor" as something separate from taste, when they're clearly synonymous? Why would I posit the existence of something unobservable which doesn't even affect anything? And you'd be right to object. There is no evidence for a supernatural attribute called "flavor" that's separate from taste. There's not even any reason for it to exist.

But you can't disprove it! (Hey, I told you this would get dumber.)

Now, suppose a person exists who is an exact duplicate of you, right down to the subatomic level. They look and behave just like you, they say the same things as you, they're as autonomous as you are, and they read the same pink website you do. For any given stimulus, they react just as you would. Because of this, they are entirely indistinguishable from you.

They aren't quite the same, though. This person is actually a zombie (no, not the flesh-hungry, undead kind of zombie). The difference is that while you possess consciousness, your zombie does not. You're aware, and aware you're aware, and aware you're aware you're aware, and so forth, but your zombie isn't. Yes, they have the exact same brain as you, with the same neural structures firing in the same patterns, they just aren't conscious. If they get punched in the face, they react as you would, but they feel nothing—there's no consciousness to feel anything. Your zombie may read a pink website just like you, but they don't perceive the color pink. Of course, if you ask them about the "pinkness" of pink, they'll demonstrate an apparent comprehension and experience of the color pink, just as you would. The absence of consciousness is not a stumbling block; the brain simply continues functioning just as it should, and gives every indication that consciousness is present. The lights are on, but nobody's home.

What does this say about consciousness? Well, as there's no physical difference between you and your zombie, consciousness is not physical in nature. Since its presence or absence makes no difference in the behavior of you and your zombie, it has no effect upon either of you. And because consciousness has no effect, it can't be observed. This is the one philosophical view that is capable of supporting the existence of zombies. It's called epiphenomenalism, and it states that while physical events cause both physical and mental events, mental events cause neither physical nor mental events^[1] (when I say "events", you can interpret that as meaning "things", or "stuff", or whichever term you find suitable). It's essentially a one-way street, with mental events being a mere byproduct—an epiphenomenon—which can't affect anything. And this is the only system in which you can eliminate consciousness, the great ongoing mental event, without inducing any observable changes. If you're a visual learner, the following diagrams may facilitate your understanding of epiphenomenalism:

Here, epiphenomena—mental events—are present. What happens when you take them away?

The ghost is gone, but the machine keeps rolling along, just the same as before. Consciousness can be entirely removed from a person without causing any changes; consequently, your own consciousness doesn't actually affect anything! Whenever you make a choice, however great or small, you aren't really choosing at all. It's simply a perfect illusion that arises from your mental events—your consciousness—precisely mirroring physical events every step of the way. Though it may seem as if you can affect physical reality, this is nothing but a constant and perpetual deception. And remember, not only are mental events unable to cause physical events, they also can't cause mental events. If you think you're the director of your thought processes, controlling your own mind, you've got another think coming—literally. Your consciousness, the very essence of that which is "you", is forever held hostage by physical events, yet you're not even aware of it. You couldn't be!

Now, if you think this is as dumb as flavorless-but-tasty Zombie Coke, you should be aware that the concepts^[2] of zombies and epiphenomenalism are endorsed, explicitly or implicitly, by lots of very intelligent^[3] people (and many more laypeople), though they all may not fully grasp its implications. But what reason is there to propose the existence of mental events as something not only separate from physical events, but also having no effect on anything, thus making them unobservable? There's certainly no evidence of these discrete and supernatural mental events, nor is there any apparent reason to make such a claim in the first place.

But you can't disprove it!

And that's exactly the problem. Epiphenomenalism, and its zombie spawn, are specifically designed to be unfalsifiable. By placing mental events firmly in the realm of the supernatural, and ensuring they have no effects, they're insulated from any sort of study or analysis. And yet this impenetrable barrier of uncertainty ultimately suffocates epiphenomenalism. Not only can it not be proven wrong, it can't be proven right! It makes no predictions, it's guaranteed to never make any predictions, and it freely admits to this, almost as if it considers this a virtue. And why shouldn't it cling desperately to that? The only thing epiphenomenalism can do is taunt us with "Well, you can't prove me wrong!", as there is absolutely no evidence in its favor. That's because there cannot possibly be any evidence in its favor. It is utterly incapable of standing on its own merits—it has no merits to stand upon, and it never will. And in spite of all this, it steadfastly refuses to recognize that any sort of proof is impossible in the very system it has constructed.

So I must ask: Why? Having defanged these supposedly supernatural mental events so thoroughly, why do epiphenomenalists insist on separating them from the physical realm in the first place? Why do they go to such great lengths to render the supernatural entirely irrelevant, but refuse to take the final step of accepting that there is no supernatural, and mental events are physical events? They've already made such compromising concessions, it certainly wouldn't change anything—after all, it couldn't! If epiphenomenalism makes no difference, and by its very definition cannot ever make a difference, what does it even do?

Nothing. When you get right down to it, there's simply nothing there. It provides no illumination of the workings of the mind, has no possible utility, and it's just plain unnecessary. It amounts to nothing more than yet another invisible, incorporeal, unobservable, undetectable dragon in the garage, floating beyond space and time. Why should we believe this dragon even exists? There is no value to be found in epiphenomenalism, and when confronted with an unproven, unprovable assertion so fundamentally flawed it verges on incoherence, we should not hesitate to reject it outright.

At this point, you might be wondering: just why do I oppose epiphenomenalism so forcefully? If it is indeed so utterly useless, why am I so bent out of shape about it? Though it may be useless, that doesn't mean it's harmless. Useless concepts can become surprisingly harmful when widely endorsed, and as I mentioned, epiphenomenalism has no shortage of supporters, whether they know it or not. Acceptance of its tenets entails various logical consequences; not only the possibility of zombies, but also:

• The hard problem of consciousness^[4] and the explanatory gap, which assert that subjective experience can't be explained solely by the mechanisms of the brain.
• The problem of other minds, which asks how we can determine whether other people are conscious, or merely zombies.
• The inverted spectrum. Imagine a precise physical duplicate of yourself who, unlike a zombie, has the same consciousness as you. However, the colors they see differ from the colors you see; for instance, they experience the chartreuse-ness of pink. Regardless, their behavior is exactly the same as yours, because their brain is identical.

Now, I must admit to having experienced some confusion over the direction of causality between epiphenomenalism and its attendant issues—how strangely appropriate. You see, I thought these problems result from accepting epiphenomenalism, and believed their obvious absurdities pose a challenge to its validity. I stand by that assessment, but this isn't how these issues were meant to be used. Rather, they are intended as arguments in favor of epiphenomenalism (or, at the very least, against physicalism, the view that all things are physical). This hadn't even occurred to me, as it would be entirely preposterous. Why? Because the premises of these "arguments" assume the validity of their conclusions.

The zombie argument is typically formulated as follows:

1. We can imagine a world exactly identical to ours, except everyone is a zombie, lacking consciousness but exhibiting the same behavior anyway.
2. Because we can imagine this, it is possible that such a world could exist.
3. If this is possible, consciousness must be non-physical in nature.
4. Because physical and mental events behave this way, epiphenomenalism is true.

Many philosophers attack this argument by claiming the zombie world cannot actually be imagined, or by disputing the notion that something is possible if it can be imagined. I'd rather focus on the conditions necessary for the zombie world to be possible. Such a world can only exist if consciousness is non-physical and affects nothing, allowing it to be added and removed without causing any changes. What view would best describe this? Epiphenomenalism. Stripped to its bare essentials, the zombie argument is revealed to be begging the question:

If zombies are possible, epiphenomenalism must be true.
If epiphenomenalism is true, zombies must be possible.

If epiphenomenalism isn't true, the proposed zombie world isn't possible, and the zombie argument falls apart, along with the rest of these arguments. They all presuppose the truth of epiphenomenalism, and therefore suffer from the same flaw. The hard problem of consciousness is only "hard" if subjective experience really is something that can't be explained by physical events. The problem of other minds is only a problem if the presence or absence of consciousness makes no difference and is thus unobservable. And an inverted spectrum is only possible if physically identical people can have differing minds, yet behave identically in spite of this. For these arguments to even have a chance at validity, epiphenomenalism must be accepted from the very beginning; if it is not, they lose their footing entirely.

What truly bothers me about epiphenomenalism is that it offers less than nothing. It goes beyond mere failure, and attempts to actively hinder our progress towards understanding consciousness. All of these arguments are bricks in a wall of ignorance, bearing the warning: "You cannot possibly know such things, so don't even try!" Lots of very intelligent people have been sidetracked into spending a great deal of time demonstrating that this obstacle is illusory, and explaining why these "arguments" are invalid and irrelevant. Unfortunately, their time has likely been wasted, as reason is toothless against the unreasoned and unreasonable.

Notes

¹ Attentive readers may wonder why identical physical events wouldn't cause identical mental events. I haven't found any answers to this, but I'm also uncertain as to whether epiphenomenalists consider it a valid issue. Others may ask how physical events can bridge the apparent gap between the physical and non-physical in order to cause mental events (and why mental events are unable to bridge the same gap), but such mechanisms are typically left unexplained—if an explanation is even possible.

² As far as I'm aware, nobody actually believes zombies exist.

³ Some might say "otherwise intelligent".

⁴ Consciousness is a very difficult problem; that is not in dispute. But in this context, "hard" has a meaning closer to "insoluble". It's interesting to note that David Chalmers, who coined the "hard problem" and supports the possibility of zombies, proposes an explanation of consciousness based on new and (purportedly) fully natural laws, much like gravitation and electromagnetism:

We know that a theory of consciousness requires the addition of something fundamental to our ontology, as everything in physical theory is compatible with the absence of consciousness. [...]

In particular, a nonreductive theory of experience will specify basic principles telling us how experience depends on physical features of the world. These psychophysical principles will not interfere with physical laws, as it seems that physical laws already form a closed system. Rather, they will be a supplement to a physical theory. A physical theory gives a theory of physical processes, and a psychophysical theory tells us how those processes give rise to experience. We know that experience depends on physical processes, but we also know that this dependence cannot be derived from physical laws alone. [...]

This position qualifies as a variety of dualism, as it postulates basic properties over and above the properties invoked by physics. But it is an innocent version of dualism, entirely compatible with the scientific view of the world. Nothing in this approach contradicts anything in physical theory; we simply need to add further bridging principles to explain how experience arises from physical processes. [...] Indeed, the overall structure of this position is entirely naturalistic, allowing that ultimately the universe comes down to a network of basic entities obeying simple laws, and allowing that there may ultimately be a theory of consciousness cast in terms of such laws. If the position is to have a name, a good choice might be naturalistic dualism.

What are we to make of this? Chalmers claims that while consciousness arises from physical events, it's non-physical and has no effect on physical events, allowing it to be removed without changing anything. How is this at all naturalistic? He's correct in one regard: this view is completely compatible with the physical realm, as it contradicts nothing. But this is an inevitable consequence of affirming that the non-physical can't affect the physical. For that reason, there's no way to observe and determine how physical processes give rise to non-physical events. How can a theory of consciousness, or of anything, be derived from the unobservable? And what evidence is there of these undiscovered laws of nature that generate consciousness? Well, such evidence could not exist, as there's nothing to observe. This is starting to sound quite familiar. Chalmers' view of consciousness isn't natural at all—it's downright epiphenomenal.