Monday, September 16, 2013

A Smidgen of Dream Skepticism

Every night I dream. And often when I dream I seem to think that I am awake. Is it possible, then, that I'm dreaming now, as I sit here, or seem to, in my office?

How should I go about addressing this question? The natural place to start, it seems to me, is with my opinions about dreams -- opinions that might be entirely wrong and ill-founded if I'm dreaming or otherwise radically deceived, but which I seem, anyway, to find myself stuck with.

Based on these opinions, I don't find it at all likely that I'm dreaming. For one thing, I tend to favor a theory of dreams on which dreams don't involve perception-like experiences but rather only imagery experiences (see Ichikawa 2009). If that theory is correct, then from the fact -- I think it's a fact! -- that I'm now having perception-like experiences, it follows that I'm not dreaming.

However, theories of this sort admit of some doubt. In the history of philosophy and psychology, as I seem to recall, many thinkers have held that when we dream we have experiences indistinguishable from waking perceptions -- Descartes held this, for example, and more recently Allan Hobson. It would be foolish arrogance to think there is no chance that they are right about this. So maybe I should I should accept the imagination model of dreaming with only, say, 80% credence? That seems pretty close to the confidence level that I do in fact have, when I reflect on the matter.

But even if I allow some possibility that dream experiences are typically much like waking perceptions, I might remain confident that I'm not dreaming. After all, I don't feel like I'm asleep. Maybe my current visual, auditory, and tactile sensory experiences could come to me in a dream, but I think I'm more rational in my cognition than I normally am when dreaming. And I recall, seemingly, a more coherent past. And maybe the stability of the details of my experience is greater.

But again, it seems unwarranted to hold with 100% confidence that dreams can't be rational, coherent, and stable in the way my current attitudes and experience seems to be. After all, people (if I recall correctly) have pretty poor knowledge of the basic facts about dream experience (for example, its coloration). Or even if I do insist on perfect confidence in the instability, incoherence, and irrationality of typical dreams, it seems unwarranted for me to be 100% confident that this is not an exceptional dream of some sort. So maybe I should do another 80-20 split? Or 90-10? Let's say the latter. Conditionally upon a 20% credence in a theory of dreams on which we have waking-like sensory experiences while dreaming, I have about 90% confidence that, nonetheless, my current experience has some other feature, like stability or rational coherence, that establishes that I am not dreaming. That would leave me about 98% confident that I am awake.

But I can do better than that! On some philosophical theories, I couldn't even form the opinion that I might be dreaming unless I really am awake. Alternatively, maybe it's just constitutive of being a rational agent that I assume with 100% confidence that I am awake. Or maybe there's some other excellent refutation of dream doubt -- a refutation I can't currently articulate, but which nonetheless justifies my and others' normal assumption, when awake, that they are indeed awake. Such theories are attractive, since no one (well, almost no one) wants to be a dream skeptic! Dream skepticism is pretty bizarre! So hopefully philosophy can succor common sense in this matter, even I don't currently see exactly how. I'm not extremely confident about any such theory, especially without any compelling argument immediately to hand, but it seems likely that something can be worked out.

Thus, I am almost certain that I am awake. Probably dreams don't involve sense experiences of the sort I am having now; or even if they do, probably something else about my current experience establishes that I am not dreaming; or even if nothing in my current experience establishes that I am not dreaming, probably there is some excellent philosophical argument that would justify confidence in the fact that I am not currently dreaming. But of none of these things am I perfectly confident. My degree of certainty in the proposition that I am now awake is somewhat less than 100%. I hesitate to put a precise number on it, and yet it seems better to attach an approximate number than to keep to ordinary English terms that might be variously interpreted. To have only 90% credence that I am awake seems far more doubt than than is reasonable; I assume you'll agree. On the other hand, 99.9999% credence that I am awake seems considerably too high, once I really think about the matter. Somewhere on the order of 99.9% (or 99.99%?) confidence that I am currently awake, then?

Is that too strange -- not to be exactly spot-on 100% confident that I am awake?


Anonymous said...

You're just dreaming that you're certain.

Anonymous said...

So, do you believe you have ever been awake? And if yes, what differences are there between your current state and what you recall? A la the more vivid drug experiences, maybe you remember that you were once fully awake, but not any details...

Keith Frankish said...

Hi Eric. When I've been thinking hard about a philosophical problem during the day, I often find myself dreaming about it at night, running over versions of the arguments. In the dream, the arguments I rehearse often seem coherent and compelling, though anything I recall on waking is usually gibberish. I'd be interested to know if you find yourself dreaming about this argument over the coming nights, and, if so, whether it seems compelling. (The topic might even trigger an episode of lucid dreaming, in which case you might be able to run a genuinely coherent argument for the view that you are dreaming.)

howard berman said...

You're assuming the world is a rational sane place. If we impose reason on a chaotic world, and the world is unstable then maybe our images in what we think are our dreams are really perceptions of an unstable and chaotic world.
I'll try to phrase this argument more clearly and coherently- but that's the first draft.
I'm sure you've had similar thoughts or somebody has

Mike J. said...

If you look at the last paragraph of the Meditations you'll see that Descartes didn't think that our dreams are indistinguishable from waking perceptions. Does that raise your confidence that you're not dreaming?

Unknown said...

Your conclusion seems natural to me.

I have often mistook dreams for reality and visa versa. I'll say to my wife, "Hey honey remember that one time we..." and she'll swear it never happened (probably a dream). And occasionally I'll think a memory was a dream when my wife will swear it was real (because she remembers it just as well as I do).

These scenarios give me pause about being 100% certain that I am awake in any given situation.

Eric Schwitzgebel said...

Thanks for the comments, folks!

Anon Sep 16 02:54: That reminds me of Zhuangzi's story of Lady Li. I'm not worried about defending myself from the skeptical flank here. If you think there's more grounds for dream doubt than I acknowledge in this post, that's fine with me.

Howard: Right. I think there are other arguments for skepticism too; and something like what you say is among them. Again, I'd assign it a very low credence, but not zero. My credence in all radically skeptical scenarios combined is about 1% (see my post on 1% skepticism).

Mike: That's a version of the incoherence objection, as I read it, which is the second of the three argumentative moves in my post; so I don't think that passage undercuts the sense-experience reading of Descartes as I use him in the first part of the argument (I would also appeal to Descartes's comments in Passions of the Soul on this point). But even if I'm wrong about Descartes interpretation, it is an opinion often enough held in the history of psychology and philosophy that dream experience is like sensory experience, that I can give it some minority credence on peer-disagreement grounds, regardless of Descartes's specific position.

Nick: Next question: If you tell your wife you are only 99.9% sure you're awake, how will she react? One of the hazards of even 0.1% skepticism is that it looks plainly wrong and foolish to outsiders who almost certainly do exist!

Mike J. said...

My comment was more idle chatter than serious philosophy. A little more seriously (but still not really seriously), I think that the difference between the first meditation and the last paragraph of the Meditations is that Descartes thinks that he's established the principle that if I'm inclined to believe something and I don't have a faculty to correct it, then the goodness of God is incompatible with my inclination being mistaken. (I think Newman says something like this in his SEP article.)

It's not clear what a belief in the existence of God should do towards the probability that you're dreaming. On the one hand, you might agree with Descartes that the goodness of God forecloses certain unfair sources of error. On the other hand, any technological obstacles to a deceiving dream would go away if God was so inclined.

I think it's less than a million to one that I'm dreaming now.

Callan S. said...

Is it possible, then, that I'm dreaming now, as I sit here, or seem to, in my office?

Alternatively, maybe it's just constitutive of being a rational agent that I assume with 100% confidence that I am awake.

Or the type of dream you are in now allows for you to consider that you are in a dream (though possibly more inclined to consider only that you are in dream type 1 (sleep associated dream) rather than dream type 2, which I describe here).

Is that too strange -- not to be exactly spot-on 100% confident that I am awake?
Possibly dream type 3 allows this formulation...

Eric Schwitzgebel said...

That sounds right about Descartes, Mike. I'm inclined to think that absolute certainty in the existence of God, much less the existence of the kind of God who would not allow you to be mistaken about such things if you reflected in the right kind of way, is unjustified -- pretty much the consensus reaction to Descartes's positive project in the Meditations, I think.

Why only a million to one? Just impressionistic, or do you have an argument?

Eric Schwitzgebel said...

Callan: Did you mean to include a link to your description of dream types 2 and 3?

Scott Bakker said...

All you need do is spin a top ;)

Do you see how this could be interpreted in 'The Mark of Gideon' terms? Essentially, your dilemma is that of Kirk's on either the false ('dream') or real ('awake') Enterprise. Empirically speaking, the difference between being in a dream state and a waking state is easily distinguished, since the brain is doing two quite different things. Assay information pertaining to these differences and presto, distinction made. Metacognitively speaking, none of this information is available, or at least decisively available. So you simply assume - sometimes wrongly. Since questions are how we flag the absence of information, any time you interrogate the difference, you bump into your metacognitive limits, and so are left with some ineliminable degree of doubt.

This kind of philosophical problem, I would argue, is the clear cut consequence of metacognitive neglect.

Eric Schwitzgebel said...

Yes, Scott, that seems like a reasonable way of framing it.

Mike J. said...

I am one of a handful of people to have ever had said anything nice in print about Descartes's argument for the existence of God.

My point wasn't that it was certain that God exists, but rather that the existence of God increases the odds that you are dreaming in one way and decreases it in another.

Why only a million to one? Just impressionistic, or do you have an argument?

Largely impressionistic. I very often have been dreaming and assumed that I was awake, but I've never been in something phenomenologically like a waking state and mistakenly thought that I was awake, and I haven't really heard of it happening to others. I guess there's a chance that the world is radically different than I think it is, but I don't think there's a good chance, and if it is, it probably isn't because I'm dreaming a dream.

I had relatively recently read this post , which may have put the number into my mind. I think that the chances that I'm dreaming should no higher than the chances of the sort of unusual event that Littlewood is talking about. It would be really weird if I were dreaming.

Scott Bakker said...

The scary thing is just how many traditional philosophical problems you can diagnose in this manner.

Perhaps it should come as no surprise that STAR TREK would hold the key to dissolving the riddles of conscious life!

Callan S. said...

Eric: I have no legitimising link! :) My post was very self referential as its means of informing the idea. And I was kind of playing around with making not much distinction between dream types until calling them 1 & 2 latter on.

In an old batman cartoon they insisted you cannot read in dreams (mad hatter had BM unconcious in a 'my parents are alive' dream). I've had dreams where I can read texts in the dream (though it was kind of large print!).

So, with the enabling or disenabling of various cognitive functions, you can get various dream types - or so I'd pitch! Or, various dream types indicate various cognitive functions lacking. Stretch out the idea and even if reflecting on whether one is in a dream - does that just make a new dream type?

Now I'll dream I can actually understand the capcha code so as to post this message...wait, crap, couldn't read it!!!???

Eric Schwitzgebel said...

Thanks for the continuing discussion, folks!

Mike: I agree with your point that the existence of God throws a wrench in things, and also with your point that it does so in a way that isn't straightforwardly unidirectional. I favor imperfection theodicies, to the extent I assign some minority credence to God's existence. Some people -- including me -- *seem* to remember falsely judging, in a dream, that they are having experiences of a waking-life sort, e.g., after a false awakening in a dream within a dream. Maybe they are wrong and this never happens, but I am not highly confident that they are wrong.

Scott: One of my dissertation advisors, Alison Gopnik, worked a Star Trek reference into every chapter of her 1997 book. I think we agree that speculative fiction is underrated as a means of exploring philosophical issues. I think it's an especially powerful tool for the skeptic -- a point I'm thinking of developing into a blog post in the near future.

Callan: Yes, it's possible that there are certain cognitive functions that reliably signal that one is not in a dream. I am inclined to think that reading stable text is not something we can do in sleep. So I'll stack that view, which I hold with >.50 credence but not >.90 credence, into the argument that I should only give a small credence to the possibility that I am now dreaming.

Mike J. said...

Some people -- including me -- *seem* to remember falsely judging, in a dream, that they are having experiences of a waking-life sort, e.g., after a false awakening in a dream within a dream. Maybe they are wrong and this never happens, but I am not highly confident that they are wrong.

Yeah, I very often either assume or judge that I'm awake while I'm dreaming, and that's the generic skeptical hypothesis that we're worried about.

But what never happens to me, and what I think hardly ever happens is that someone is in a phenomenological state like the one I'm in now and falsely thinks that she's awake. The production values for the present experience are too high.

So, do all the tests that they tell you to try in Waking Life: try switching light switches, reading clocks, and reading small letters. (I'm not going to get up to flip the light switch. I know what would happen.)

Set aside the cases where you're doped up or feverous for one reason or another. Consider you're present clear headed state (I assume that you're clear headed. If not, the odds are different.) In cases where everything seems clear and the little letters are visible and stable, there's no ordinary chance that you're asleep.

Little Gold Eunuch (For Your Consideration...) said...

Given that we remember little of what we dream, how can we know even in principle if "
But what never happens to me, and what I think hardly ever happens is that someone is in a phenomenological state like the one I'm in now and falsely thinks that she's awake."?

Putting aside drugs and mental illness, which really put a spanner in the works, I know at least one person who has thought she was in bed dreaming, but turned out (she thinks!) to have been awake.

Some very bizarre things happen in real life, and I have frequently come up with excellent rationalisations for strange things happening in dreams.

The more I consider this issue the less I believe the distinction between dream and reality holds true, and that we are in an infinite branching circular structure of dreams within each other and themselves.

Also, I wrote some film satire using this account a while back. Do let me know if you think it's funny!