• Aaron R
    218
    Let's open up this can of worms again...

    The dream argument attempts to demonstrate that belief in the existence of an "external" world is never justified. The argument apparently traces its roots to Pyrrohnian skepticism, but ultimately found it most popular and memorable expression in Descarte's Meditations.

    Klein, in his SEP article on skepticism, contends that the Dream argument conforms to the following schema:

    1. If I know that p, then there are no genuine grounds for doubting that p.
    2. U is a genuine ground for doubting that p.
    3. Therefore, I do not know that p.
    — Klein, 2014, Skepticism, SEP

    A suitable appropriation might look something like this:

    1. If I know that the object I am holding in my hand exists independently of my mind, then there are no genuine grounds for doubting it.
    2. If I were now dreaming, then there would be ground for doubting that the object in my hand exists independently of my mind.
    3. Therefore, I don't know that the ball in my hand exists independently of my mind.

    The argument turns on several considerations, but here are a few of the most important:

    1. Having grounds for doubting a claim is incompatible with a claim counting as knowledge.
    2. Dreams are (in principle if not in practice) epistemically indistinguishable from waking experience.
    3. Mind and world are ontologically dichotomous, with experience being entirely "internal" to the mind (e.g. qualia, ideas, representations, etc.) and the world being entirely "external" to it.

    I've found that a person typically finds the argument convincing to the extent that they find the above considerations convincing.

    Do you think the argument is a decisive objection those who think belief in the mind-independent existence of the world is justified? Why or why not?
  • Marchesk
    4.6k
    One problem with the argument is that dreams are epistemically distinguishable from waking experience, in that they do differ quite a bit from waking experience. It's just that usually our ability to judge is suspended while dreaming, although not always. In lucid dreaming, we do realize we're having a dream, and can take control of it to some extent. It's not like we go to sleep and experience another life just like the one we're having, such that we can't tell which is the real life upon waking. Dreams often don't make sense, they're jumbled up and weird. They don't follow the rules of waking perception.

    However, the reality of dreaming does raise the spectre that all experience is going on inside my head. If I can dream of people, trees, colors, sounds, even feels on occasion, then what makes my perceptions fundamentally different? A challenge for direct realism is to account of the fact that sometimes, we do experience an internal world (this also applies to daydreaming).

    This, I suppose, is the motivation for some, like Dennett (at least in the past, not sure about now), to deny that we actually dream. Instead we "come to seem to remember" upon wakening. Thus, dream skepticism can be avoided. But I find that entirely unbelievable.
  • Real Gone Cat
    346
    Following the appropriation, only if a person were unable to distinguish between dreaming and non-dreaming would they have grounds to doubt. But, not being able to know when they were in a dream state, they would not have reason to believe that they were ever in a dream! In fact, they would not even know what a dream was - even if you tried to explain it to them (like trying to explain blue to a blind man).

    EDIT : After re-reading this, I realized that it might not be clear as to what I was trying to say.

    Conclusion : The act of dreaming can never be used as grounds for doubting existence-sans-minds. Either we know the difference between dreaming and non-dreaming and could not logically use dreaming to disprove something about non-dreaming or, we do not know what a dream is and cannot hold it up as evidence for doubt.
  • wuliheron
    440
    Reality without dreams is just somebody's nightmare, while dreams without reality are someone else's fantasy. Stay awake long enough and you will hallucinate, while reality always catches up to us in our dreams because one without the other is a demonstrable contradiction. Someone without dreams is a statistic of one which is just flat out impossible and even suicides have turned out to be much more common among those with a history of making poor decisions and having poor impulse control. Without both reality and dreams, memories and awareness, there's simply nothing to discuss and nothing to be done about it.
  • Nerevar
    10
    I believe that the argument for the world as a dream isn't to say that the world is identical to a single human dream, but rather that since it is possible to be fooled as to what is real, it is possible that the entire universe is no more real than a dream. The fact that we can point out that it is more internally consistent and persistent than a human dream is irrelevant. It still boils down to a series of experiences that can be doubted.

    In the end, the dream argument is more of an argument through metaphor than a logical argument. If you were to bring logic into it, you'd have to have an ultimate reason for something to exist, rather than nothing. Since there can be no ultimate reason, nothing can logically exist. Since 'somethingness' is logically untenable, it cannot be true. Thus, anything appearing to exist is false, such as dreams and balls and universes. The real fun begins when you begin to define nothingness, which is true.
  • Terrapin Station
    13.8k
    Do you think the argument is a decisive objection those who think belief in the mind-independent existence of the world is justified?Aaron R

    I'm one of the realists around here. I don't think it's a decisive objection at all. One big problem with it is that it confuses the conceivability that not-p, or the coherent possibility of doubting that p with grounds for doubting that p. Grounds for something need to be more than conceivability or coherent possibility. After all, just as it's possible that one is merely dreaming that p, it's also possible that "one is dreaming that p" is false just as well. So if possibility is sufficient for belief, it's required that one believe contradictory claims, p and not-p, for almost every claim.
  • Michael
    15.6k
    I'm one of the realists around here. I don't think it's a decisive objection at all. One big problem with it is that it confuses the conceivability that not-p, or the coherent possibility of doubting that p with grounds for doubting that p. Grounds for something need to be more than conceivability or coherent possibility. After all, just as it's possible that one is merely dreaming that p, it's also possible that "one is dreaming that p" is false just as well. So if possibility is sufficient for belief, it's required that one believe contradictory claims, p and not-p, for almost every claim.Terrapin Station

    That it's a contradiction to believe two opposing things is not that it's a contradiction to claim that neither thing is sufficiently justified.
  • Wayfarer
    22.5k
    The argument apparently traces its roots to Pyrrohnian skepticism,Aaron R

    I think it would be useful to provide some context by providing some detail on Pyrrhonian scepticism.

    Pyrrho summarized his philosophy as follows: "Whoever wants to be happy (eudaimonia) must consider these three questions: First, how are pragmata (ethical matters, affairs, topics) by nature? Secondly, what attitude should we adopt towards them? Thirdly, what will be the outcome for those who have this attitude?" Pyrrho's answer is that "As for pragmata they are all adiaphora (undifferentiated by a logical differentia), astathmēta (unstable, unbalanced, not measurable), and anepikrita (unjudged, unfixed, undecidable). Therefore, neither our sense-perceptions nor our doxai (views, theories, beliefs) tell us the truth or lie; so we certainly should not rely on them. Rather, we should be adoxastous (without views), aklineis (uninclined toward this side or that), and akradantous (unwavering in our refusal to choose), saying about every single one that it no more is than it is not or it both is and is not or it neither is nor is not.

    Adiaphora, astathmēta, and anepikrita are similar to the Buddhist Three marks of existence, suggesting that Pyrrho's teaching is based on what he learned in India, which is what Diogenes Laertius reported.
    — Wikipedia

    (Ref: Beckwith, Christopher I. (2015). Greek Buddha: Pyrrho's Encounter with Early Buddhism in Central Asia. Princeton University Press. p. 28.)

    The point is that Pyrrho's original intention was soteriological, i.e. concerned with attaining 'ataraxia', equanimity or imperturbability; it was a different kind of attitude to the later development of academic scepticism and sophistry, or 'doubt for the sake of doubting'.
  • Janus
    16.3k


    Realism is sufficiently justified only insofar as it is implicit in the logic of all our linguistic usages; but not beyond that. Beyond that it is simply incoherent. The notion that everything might be a dream is doubly incoherent; both in terms of our linguistic usages and beyond that as well.
  • Michael
    15.6k
    The notion that everything might be a dream is doubly incoherent; both in terms of our linguistic usages and beyond that as well.John

    The "everything might be a dream" hypothesis just suggests that the relationship between waking experiences and whatever mind-independent things explain the experiences might be similar in kind to the relationship between dreams and the brain, i.e. there's a causal relationship between the two but no constitutive relationship such that the experience (or dream) is of its cause. When I dream of a tree I'm not dreaming of my brain, even though my brain is the cause of the dream, and so when I see a tree I'm not seeing whatever things are the cause of the experience, even though they're the cause of the experience.

    It might be wrong, but I don't see how it could be incoherent.
  • Janus
    16.3k


    I see it as incoherent because it relies on an analogy with a relationship that is meaningful only within a context. And this very context, and hence the meaningfulness of the relationship the hypothesis is dependent upon, is denied by the hypothesis itself.
  • ssu
    8.6k
    2. Dreams are (in principle if not in practice) epistemically indistinguishable from waking experience.Aaron R
    You even say it here yourself: in principle if not in practice. That "in principle" is thus a quite limited argument when it goes against practice.
  • Mongrel
    3k
    You even say it here yourself: in principle if not in practice. That "in principle" is thus a quite limited argument when it goes against practice.ssu

    "In principle" is enough for a hefty argument. If it's true that there's nothing I might observe (even in principle) that would tell me whether I'm dreaming, then per Leibniz's Law, there is no difference between this and a dream.

    Leibniz's Law is a bi-conditional that claims the following: Necessarily, for anything, x, and anything, y, x is identical to y if and only if for any property x has, y has, and for any property y has, x has.
  • jkop
    905
    The dream argument attempts to demonstrate that belief in the existence of an "external" world is never justified.Aaron R
    That's a bad argument. You shouldn't ask for justification of belief in the existence of an external world under the assumption that the external world doesn't exist, or that we would never encounter the external world, only our own internal constructs.
  • Aaron R
    218
    Interesting. Most here seem to agree that the argument either fails or is not decisive, and for similar reasons. I thought we'd see more defenders of the argument (or some variation of it). Ah well.

    For my part, I don't think it works either, for reasons similar to those provided above. I thought 's analysis provided in his "conclusion" was particularly pithy.
  • Cavacava
    2.4k
    I've always found the dream argument interesting. The argument only seems feasible (to me) because we understand the difference between being awake and being asleep and in knowing this difference we can at the same time logically deny our ability to cognitively differentiate between these two forms of experience. Perhaps a fault in applying logic to experience, not logically incorrect but practically incoherent.
  • jkop
    905

    But experiences are not objects of observation; it's trivially true that you don't observe whether this has dreamy or veridical features... and from the lack of such observation it doesn't follow that there would be no difference between this and a dream.
  • Mongrel
    3k
    But experiences are not objects of observationjkop

    Is there a difference between the dream table and the real table? What properties does one have that the other doesn't?
  • Janus
    16.3k


    You can fly off the dream table, or it could turn into something else.

    On the other hand you probably cannot choose to do a comprehensive spectroscopic and carbon dating analysis of the dream table or have it be reliably there for use for the next twenty years.
  • jkop
    905
    What properties does one have that the other doesn't?Mongrel

    Unlike the dream the real table has the property of being the object of your experience of a table. For example, its present features in your visual field cause your visual experiences of it.

    The dreamt table, however, is not causing your dream of it, instead it is evoked by your memories of a table, or your will, habits, or familiarity with describing tables.

    The two experiences might be momentarily indistinguishable despite their difference in objects experienced, but it is not difficult to find out whether there is a table in your visual field.

    The mistake of the skeptic is to assume that what the dream and the veridical case have in common would also be the object that you experience, or an element of the experience. It isn't. They only have in common what is constituitive for any experience, brain events. They differ, however, in what causes them, e.g. the real table as the intentional object of perceiving it, and in the dream it is your memories etc.
  • Mongrel
    3k
    You can fly off the dream table, or it could turn into something else.

    On the other hand you probably cannot choose to do a comprehensive spectroscopic and carbon dating analysis of the dream table or have it be reliably there for use for the next twenty years.
    John

    Among the table's properties is that you can fly off of it? But one can fly off a real table. A real table can change into something else. There may be in there some marks of distinction between dreaming and reality, but I don't think it has to do with the table's properties.

    Dream tables can definitely be carbon dated and spectroanalyzed. If it's my dream, the analysis will inevitably yield some odd results like it spells the word "Fractured," or it's the name of a King, but I don't know which King and maybe it's a chess King.

    A dreamworld is not a duplicate of the real world. It's usually pretty easy to tell them apart objectively.. But dreams do have quite a bit in common with the real, and the real has quite a bit in common with dreams.

    If it's Descartes' dream argument we're talking about, it's not a side-by-side analysis we're doing anyway. It's a subjective thing. Are you dreaming now? If not, how do you know? What tells you that you're not?
  • Mongrel
    3k
    its present features in your visual field cause your visual experiences of it.jkop

    You'd say exactly the same thing in the dream if the question came up.
  • jkop
    905

    Nothing is literally said in the dream.
  • Mongrel
    3k
    "You said that P in the dream" is true IFF you said that P in the dream.
  • jkop
    905

    You're not making sense. Would you care to explain?
  • Punshhh
    2.6k
    I thought we'd see more defenders of the argument (or some variation of it). Ah well.
    Perhaps I can help. It occurs to me that if one looks at the issue in terms of the occurrence of being, rather than the experience of that being, there is equivalence. So in a dream, a being finds herself in a dream. Likewise upon birth a being finds herself in a world. Irrespective of whether there are circumstances in experience to suggest that a being in a dream is caused by something in experience, empirical( a birth might likewise have a full complement of causes, which we are not aware of).These two instances of a being finding themselves somewhere are the same. Like a process of waking up, a being arrives somewhere through an unknown process, one ocassion a dream and another a birth into a world.

    So it seems to me that in both cases, we are simply describing the physical conditions which appear to result in these two examples of beings finding themselves somewhere and then deciding that one, being born, is more real than the other. In the ignorance of the basis of being and how beings come into being.

    An aside, I have on ocassion woken from a dream with a strong sense that I am awake, only to find subsequently that I am still asleep and in a dream, a dream in which I am convinced I am awake. Then I wake up again and have to concentrate really hard on where I am and we're I was before I fell asleep, to establish that I am indeed awake.
  • Terrapin Station
    13.8k
    That it's a contradiction to believe two opposing things is not that it's a contradiction to claim that neither thing is sufficiently justified.Michael

    I didn't say anything about it being a contradiction to say that neither thing is sufficiently justified.
  • Michael
    15.6k
    But you were addressing @Aaron R's question "Do you think the argument is a decisive objection those who think belief in the mind-independent existence of the world is justified?". So the objection is "a belief in realism isn't justified", and you "don't think it's a decisive objection" because "it's required that one believe contradictory claims".
  • Terrapin Station
    13.8k


    So what? How in the world are you getting from that question and my response that I was saying something about it being a contradiction to say that neither thing is sufficiently justified?
  • Michael
    15.6k
    So what? How in the world are you getting from that question and my response that I was saying something about it being a contradiction to say that neither thing is sufficiently justified?Terrapin Station

    The objection is "the belief that we're not dreaming isn't justified because there are ground for doubting it". You suggested that the same can be said about the belief that we are dreaming; it isn't justified because there are grounds for doubting it. And you said that because this entails believing contradictory things, the objection fails. But it doesn't involve believing contradictory things. It isn't a contradiction to claim that both the belief that we're not dreaming and the belief that we're dreaming are not justified.
  • mcdoodle
    1.1k
    Klein, in his SEP article on skepticism, contends that the Dream argument conforms to the following schema:

    1. If I know that p, then there are no genuine grounds for doubting that p.
    2. U is a genuine ground for doubting that p.
    3. Therefore, I do not know that p. — Klein, 2014, Skepticism, SEP
    Aaron R

    I've just been reading Fogelin on skepticism so I may be writing Under The Influence. My feeling is that this is all what he would call 'Cartesian' rather than Pyrrhonian skepticism: some rules for debate are pre-assumed in which 'genuine' can reasonably be defined, for instance, so it's only skepticism within a certain framework, not skeptical of the framework.

    I can imagine - indeed a friend told me there really is such a thing, but the reality or not doesn't matter for the argument - a society in which dreaming is held to make more sense than awakeness, and to bring one closer to the divine. In their society the boot is always on the other foot: how can you be sure you're not awake when you hope and believeyou are dreaming?

    Even to be able to imagine such a society is to say that any assertion can be doubted, any claim to knowledge is in some way contextual. It depends upon the company you've been keeping and what you're talking about with them, on what mutual terms.

    Mostly this doesn't matter, for 'knowing' is understood in a certain way as between, say, scientists, or lovers, or people who have an intuitive mutual understanding, or philosophers talking about epistemology. So Pyrrhonians - on this view - happily say 'Yes, I know' and mean it at the time.
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