Monday, February 19, 2007

Do We Believe What We Dream? (by guest blogger Jonathan Ichikawa)

I guess it's pretty standard to think that when we dream that p, we believe that p. Why?

To clarify the question: obviously, if I dream that I'm a famous opera singer (when in fact I am not a famous opera singer), it's part of the dream that I believe I'm an opera singer, and it's false that I'm an opera singer. But the question I'm engaging in isn't whether I believe it in the dream; it's whether in fact I believe it during the time that I'm dreaming. (Compare: in the dream I am performing at the Met; in fact, I am in my bed, which is not at the Met.)

If I knew the correct theory of belief, this might not be too hard a question to answer. We'd just see whether my dream state falls under that theory. Unfortunately, I don't know what the right theory of belief is. But it looks to me like most of the candidate theories will make the "you believe what you dream" view problematic. That's good news for me, because I reject that view -- but it also makes me wonder whether I'm missing something, in light of the fact that the dream belief view is so standard.

So are there plausible views about belief on which it turns out that we believe what we dream? Laura is sleeping in bed, dreaming that she is in England. What could make it true that she believes herself to be in England?

Some philosophers hold that beliefs necessarily play a certain kind of functional role; that what it is for a mental representation to be a belief is for it to play a distinctive belief-like role in a subject's cognitive economy. But, dream beliefs do not appear to play many of the same functional roles as do prototypical beliefs. Functionalists are of course free to specify which cognitive functions are distinctive of belief, but I am skeptical about there being a satisfactory specification of the functional role of belief that includes Laura's representation I am in England, but excludes obvious non-beliefs, like the representation Laura has when she fantasizes about being in England while awake.

Likewise, if one is tempted by an interpretationalist or dispositionalist theory of belief, one will have difficulty granting belief status to dream beliefs. Let's observe Laura as she's dreaming. On what basis can we ascribe to her the belief that she is in England? She is not behaving as if she is in England – she is not
looking to the right before crossing streets. Neither does she give us utterances that are best interpreted as expressions of the belief that she is in England, so any kind of Davidsonian radical interpretation is out of the question. Indeed, she's exhibiting very little behavior at all, since she is asleep. What is it about Laura in virtue of which she believes she is in England?

Eric, I think, has defended a view relating beliefs to long-term dispositions -- Laura's I'm in England representation definitely isn't one of those. It'll be gone when she wakes up, if not sooner! Maybe Eric can clarify whether I'm interpreting his view right, and how dreaming could fit in.

So, why would anybody think we believe what we dream?


Eric Schwitzgebel said...

Delightful post, Jonathan! (And you do have my view of belief right.)

If one thinks that behavioral dispositions are central to belief (as I do), then one question is: Do we behave (or act) in our dreams? I don't actually cross streets of course, but I can imagine someone suggesting that there's a sense in which I do something internally indistinguishable from crossing a street; and maybe what's essential to belief is just what that internal "as if crossing the street" thing has in common with actually crossing the street. I don't think I'd go that way myself; but on the other hand, if we don't accept something like that, maybe it makes our work against the dream skeptic too easy? I know that I believe I'm here in Kinko's; if it were a dream, I wouldn't believe it; therefore I'm not dreaming.

Another issue is reasoning. Sometimes in dreams, I think, I make inferences. Is there a way to make sense of this, if I'm not believing? (Maybe so -- parallel to inferences within fictions?) And even if I'm not believing, at least there's a functional role or set of cognitive dispositions that are analogous to or similar to that of belief: The tendency to draw Q from P and P->Q.

Anonymous said...

This was a very helpful post for me Jonathan. Thank you. I have not thought much about belief ascription in relation to imaginative simulation. Your thoughts about dreaming seem applicable to a lot of things, including the reading of fiction. I hope to see more on this.

If much of our general experience of the world is rooted in imaginative simulation (I’m currently inclined to think so), the gap between real belief and belief within our story-worlds might not be very large . . .

Anonymous said...

Thanks, Eric. A few thoughts:

...if we don't accept something like that, maybe it makes our work against the dream skeptic too easy? I know that I believe I'm here in Kinko's; if it were a dream, I wouldn't believe it; therefore I'm not dreaming.

A major part of my dissertation is basically a response to this suggestion. Ernest Sosa thinks that the imagination model does give us this easy response to dream skepticism; I disagree, suggesting instead that, given the indistinguishability and non-identity of 'dream belief' from belief, it's a mistake to think of false beliefs as having an essential role to play in skeptical arguments.

RE: reasoning: Since I think that we imagine what we dream, instead of believe it, that we reason with our 'dream beliefs' isn't a threat to my view. Because we reason with our imaginings in just the same way as we do with beliefs.

Clark Goble said...

Great post.

Dreams are just so odd on many levels. For instance when I first wake up the "dream" often seems real and I'm for a moment troubled by reconciling the waking world with the "reality" of the dream world. Further, for at least several minutes, I have full memory of the dream world as if it were part of my consciousness. That is it appears that I was conscious as I was dreaming even though we'd say I wasn't conscious.

I half way wonder if some of the problems of dreaming and beliefs are related to the problem of consciousness and dreaming.

The other odd thing is if, in a dream, I believe I am dreaming. Now is that a belief? Yet often within a dream while staying in the dream state I appear able to distinguish what is or isn't a dream and access the non-dream reality. It's quite odd.

Anonymous said...


Perhaps the following is relevant.

For many years, when I lectured on Descartes and his stuff on the skeptical hypothesis that perhaps one is dreaming right now, I would emphasize that one's dreams are never actually what I would call "a Cartesian dream": An incredibly realistic dream in which you wonder for an extended period of time whether you are dreaming and are convinced after a while that you are not dreaming.

However, I stopped giving that lecture when I one day (night) had a full-blown Cartesian dream. In this dream I did all sorts of things to test wheter I was dreaming: I examined my surroundings for fantastic violations of natural law; I scrutinized the intricate details of the woodgrain in my desk and the hairs on the back of my hand; etc. After a series of inqueries, I arrived at a mental state that was introspecitviely indistinguishable from a belief to the effect that I was not dreaming.

I'm convinced, retrospectively, that the whole thing was a dream. (Largely due to the episode's being book-ended by my being in bed.) But at the time, I subjected my mental state to all of the introspective tests I would normally run if asked to figure out what I really believe.

Assuming that everything I wrote above is sincere (it is!), then wouldn't that be a pretty powerful consideration for concluding that, at least sometimes, we believe what we dream? I think it would be. I think further that a decent functionalist theory of belief should be consistent with this.

Eric Schwitzgebel said...

One thought: The fact that you now believe that you had such a dream is not, in my view, conclusive evidence that you did in fact have such a dream. (You know my usual skepticism about reports about the stream of conscious experience.)

But, just for fun, let's suppose (as might be the case) that you did have a "Cartesian dream". Jonathan, are you committed to the impossibility of that?

Anonymous said...

Sorry for the slow response!

Pete, I think that the dream you describe is possible, even given my view that we do not believe the contents of our dreams in virtue of dreaming them. Can you tell me more about why you think it represents a "be a pretty powerful consideration for concluding that, at least sometimes, we believe what we dream"?

Is the idea that anything subjectively indistinguishable from a belief must be a belief? I deny this. This has some interesting and surprising consequences for consideration of dream skepticism.

Eric Schwitzgebel said...

Jonathan, I'm curious how the possibility of a Cartesian dream fits with your imagination model of dreaming. There's an old literature that suggests that vivid images are qualitatively indistinguishable from sensory experiences. Are you accepting that, or...?

Anonymous said...


I don't know if subjective indistinguishability is sufficiently clear for me to know what I'd be agreeing to. On some readings, that's what I meant to suggest. Here's another way of putting it.

All of the tests I myself can perform to see whether I believe P can be performed in a Cartesian dream.

I presume you wouldn't want to deny that we can have beliefs even under conditions in which we are systematically deceived. I also presume that we ought to embrace the possibility of belief formation and testing in systematically decptive environments like the Truman Show soundstage or Star Trek's holodeck.

Assuming that you agree with these presumptions, I'm left wondering what the crucial difference is between the Cartesian dream and being fooled some highly convincing Virtual Reality.

Anonymous said...


Given the possibility of a Cartesian dream, I'm committed to the following: there are possible cases in which we experience imagery/imagination and are unable to recognize them as imagery/imagination.

That's weaker than the claim that vivid images are qualitatively indistinguishable from sensory experiences, because it leaves open the possibility that the reason we're unable to distinguish them is that we're cognitively impaired, or not attending to the right features of the experience.

Anonymous said...

Pete: I'm not quite sure I see what you're getting at. Tell me if this helps.

I think that this -- All of the tests I myself can perform to see whether I believe P can be performed in a Cartesian dream. -- is false. I'm not sure what tests you have in mind, but unless they're all very internal, I don't see any reason to think that this will be true.

I think I agree with the things you're assuming I agree with, if I understand them properly. Then you ask:

Assuming that you agree with these presumptions, I'm left wondering what the crucial difference is between the Cartesian dream and being fooled some highly convincing Virtual Reality.

Crucial with respect to what? One interesting difference is that I think, and have argued, that in the Cartesian dream, we don't have false beliefs. There are other differences too, but without knowing what's motivating the line of questioning, I don't know how to say which ones are crucial.

Anonymous said...


I think maybe I'm losing track of the dialectic here but maybe the following helps.

You grant that there can be belief in the holodeck/Truman show cases but not in the Cartesian dream case. The question I'm pressing concerning the difference is: what's the crucial difference between the cases in virtue of which the dream case doesn't have belief?

Is the crucial difference behavior? It matters that I'm relatively immobile and in bed? Does paralysis likewise prevent one from having beliefs?

Is there something about the functional roles of beliefs that are thereby changed? If, unawares, a virtual reality helmet was placed on you, you could be fooled into believing in the presence of objects that aren't actually before you. This wouldn't change the functional roles of your cognitive economy in so radical a way that you would be prevented from believing the existence of these virtual objects. Why think the Cartesian dream is any different?

Of course, there is the question of why think the Cartesian dream is relevantly the same. My answer is (i)that it seems the same, (ii) while having it I attempted to ascertain what it was that I believed and came to the conclusion that I believed that such-and-such was real, and (iii) retrospectively I maintain that I did indeed hold those beliefs that I now reject. Those constitute at least prima facie reasons for accepting that at least sometimes we believe what we dream. I don't see that I'm obligated to derive them from some other principle (like, "everything subjectiviely indistinguishable from a bleief is a belief"). If functionalism or behaviorism somehow proves me wrong, I'm going to need a lot more convincing. In particular, I'm going to need to see how behaviorism/functionalism can consistently rule out dream beliefs while granting them in the holodeck/truman show cases.

Does this help at all?

Anonymous said...

Thanks, Pete, that does help. Whether or not you lost track of the dialectic, I definitely lost track of it. I think I'm on board now.

I don't know the answer to your question, because I don't know what it takes to be a belief. Different theories will give different answers. Behavior might have something to do with it, although you're right that paralysis presents a complication. Maybe some more internal notion of behavior is what's key.

I agree that there are important unanswered questions here. There's more work to be done. I guess the extent to which one is dissatisfied with what I've said so far will depend on how much he trusts introspective and memory reports of dream experience.

Anonymous said...

um, is it just me, or should you maybe credit the origin of the idea you discuss in your post to Sosa? Your single mention of Sosa in a comment could leave readers thinking that Sosa thinks the thought you attribute to him in response to the interesting thesis about dreams you mention. Which you got from Sosa.