• PossibleAaran
    243
    Do we know that anything exists when unperceived?

    I believe that there are items which exist when neither I nor anyone else is perceiving them. Examples of such items are pieces of paper, seas, mountains and apartment blocks. I believe it, but how could I possibly know it?

    To answer this question, we need to be more precise about what is meant by 'know'. I find it helpful to distinguish two senses of 'know'. In one very strong sense, I could only 'know' that P only if I could prove that P to anyone who might doubt it, using premises which any reasonable person would accept. This is the sense of 'know' which goes with the Regress Problem that began with the ancient sceptics. In another sense, I 'know' that P only if there is some reliable method by which I could establish that P. Note that reliability is a de facto concept. A method can be reliable even if I have no way of proving that it is reliable to anyone who doubts it, and even if I couldn't prove it to even a single person. For a method to be reliable is merely for it to be a method which, when used in the right circumstances and in the right way, produces beliefs which are true more often than not. Thus, in this sense, a tarot card readings that give insight into the after life might be reliable even if there is no way to prove that they are. The sense of 'knowledge' is hence considerably weaker than the first sense.

    I shall use 'knows' in the second sense, since there is already a thread about the first issue. When I ask how I could possibly know that anything exists unperceived, I mean to ask how I could reliably establish it. Is there any method available to me which is such that it is a reliable means of determining that something exists unperceived? The more I think about it, the more it seems to me that I really couldn't know it. Yet, I still hope that I can.

    Context: Some time ago I made a thread in which I distinguished a number of forms of scepticism. I asked others whether they could think of any others. I eventually got into a discussion about whether anything exists unperceived with a few others. The discussion was accidentally lead into confusion by me. I failed to distinguish carefully enough between the two senses of 'knows' above. I began insisting that I cannot know, in the weak sense, but when my position was criticized I conveniently shifted to the strong sense. This made my position look stronger, but it was clearly a case of equivocation, and I didn't even realize it.

    Best,
    PA
  • Michael
    15.4k
    Black holes and dark matter? They can't be seen, but we know of them because of their gravitational effects on other things.

    If you want to talk hypotheticals, we could know that there's an invisible something in the room if we bounce a ball off it.
  • PossibleAaran
    243
    I am not particularly concerned about black holes or dark matter here. In front of me at the moment is a piece of paper. How do I know that this piece of paper still exists when I put it away in my desk and leave the room?
  • MindForged
    731
    Because you haven't given a reason to motivate believing existence or persistence is dependent upon perception.
  • celebritydiscodave
    79
    Everything exists unperceived, because everything exists very slightly to one side or the other of perception. Easy question so an easy answer for it. This is the way of true philosophy. If every living thing were to die that possesses the facet perception then the reality of their being would be no more, but whilst one exists, perception exists and so also does the reality of their existence..
  • Michael
    15.4k
    How do I know that this piece of paper still exists when I put it away in my desk and leave the room?PossibleAaran

    Does knowledge require certainty or just (strong) justification? If the former then you might not be able to know. If the latter then that depends on what counts as (strong) justification. Perhaps the fact that things tend to be found where they're left is evidence that you will find it if you look there again, and perhaps it's more reasonable to believe that if things are found where they're left then they were there all along than to believe that they "pop" into and out of existence when you look.
  • PossibleAaran
    243
    Because you haven't given a reason to motivate believing existence or persistence is dependent upon perception.MindForged

    So? Lacking a reason to think that Not-P is not a reliable means of establishing that P. It isn't a reliable method of establishing anything.

    Does knowledge require certainty or just (strong) justification? If the former then you might not be able to know.Michael

    I explained what I meant by 'knowledge' in the OP.I don't mean to require certainty or justification. I only require that, whatever the method is that we use to determine whether or not things exist unperceived, the method be reliable.

    perhaps it's more reasonable to believe that if things are found where they're left then they were there all along than to believe that they "pop" into and out of existence when you look.Michael

    Why is it more reasonable to believe that things exist unperceived than that they pop into existence? What is better about the former belief?

    Best,
    PA
  • Michael
    15.4k
    Why is it more reasonable to believe that things exist unperceived than that they pop into existence?PossibleAaran

    I didn't say it is. I said if it is. I don't know how one would go about showing that one is more reasonable than the other. Perhaps parsimony?

    A related question, though, would be would it matter? Or is it just a matter of intellectual interest?
  • Rich
    3.2k
    I believe that there are items which existPossibleAaran

    The issue here is the word "exist".

    Is there something out there in the fabric of the universe? Probably yes.

    But what is it until Mind perceives it? That is the question.

    It is like sound waves that are simply waves until the Mind hears it.
  • MindForged
    731
    So? Lacking a reason to think that Not-P is not a reliable means of establishing that P. It isn't a reliable method of establishing anything.

    From your OP I assumed you accepted that objects that we perceive exist. If that is the case, to give any reason to believe they do not exist when unperceived, don't you need to establish some causal relation between perception on one hand, and existence (or at least persistence) on the other? Otherwise it just looks like an arbitrary speculation.
  • PossibleAaran
    243
    Perhaps parsimony?Michael

    Maybe. But there is more than one type of parsimony, and it isn't clear that the view that some things exist when unperceived is more parsimonious in every sense than the view that things disappear when we aren't looking.

    Its even less clear that a more parsimonious explanation is more likely to be true than a complex one. Although, I'd certainly take a great interest in any detailed statement of this argument from parsimony.

    would be would it matter? Or is it just a matter of intellectual interest?Michael

    Well it matters to me since it is something that I believe, and I don't want to believe anything that I have no reliable means of determining. Ultimately, what matters and what doesn't depends on what we care to discuss.

    Is there something out there in the fabric of the universe? Probably yes.

    But what is it until Mind perceives it? That is the question.
    Rich

    Is there anything at all when the mind isn't perceiving? That is the question I am asking. If your answer is 'probably yes', why do you say that?

    If that is the case, to give any reason to believe they do not exist when unperceived, don't you need to establish some causal relation between perception on one hand, and existence (or at least persistence) on the other? Otherwise it just looks like an arbitrary speculation.MindForged

    But I never attempted to prove that things don't exist unperceived, so I don't need to establish any causal relation between perception and existence. I asked whether there is any way that I can know that things do exist when unperceived. I haven't speculated at all. Simply raised a question.

    Best,
    PA
  • Rich
    3.2k
    Is there anything at all when the mind isn't perceiving? That is the question I am asking. If your answer is 'probably yes', why do you say that?PossibleAaran

    Two reasons:

    During one's life, one is always perceiving new things as one develops skills in perception.

    Other life forms are reacting to things we do not perceive.
  • MindForged
    731
    But I never attempted to prove that things don't exist unperceived, so I don't need to establish any causal relation between perception and existence. I asked whether there is any way that I can know that things do exist when unperceived. I haven't speculated at all. Simply raised a question.

    Well I can raise a question about any old thing I want. Perhaps mathematical truths are only true when a conscious being considers their truth value. But as with your "simple question", unless there is a reason to motivate considering the question as being true or at least plausible, it seems like idle speculation. And that you seem to accept that objects exist when perceive would entail some kind of relationship between existence and perception if we wish to raise a question about if they exist unperceived.
  • Daniel
    458
    The fact that you exist necessarily implies that everything that is outside you exists since it is something that is not you, and hence it is. The same applies to everything that you can perceive. That is, the fact that a paper sheet exists, which you are able to prove through your sense-perception, implies that everything outside the limits of the paper sheet exists, for what is outside the paper sheet is not the paper sheet, and thus it is. Therefore, even if you stop perceiving the paper sheet, what is not the paper sheet, ie. you and everything else that is not you or the paper sheet, by existing, causes the paper sheet to maintain its state of existence, for the paper sheet can only be that, a paper sheet. If it were the case that as soon as you stoped perceiving an object it would stop existing or it would exist in some other way, the change in the state of existence of the object would necessarily cause a change in your state of existence and in the state of existence of everything you are now perceiving. However, because this is not the case, it is same to assume that the contrary is what is real. Let me know what you think.
  • PossibleAaran
    243
    During one's life, one is always perceiving new things as one develops skills in perception.Rich

    This is compatible with everything ceasing to exist when no one is perceiving it, so how does this support the view that things exist unperceived?

    Other life forms are reacting to things we do not perceive.Rich

    How can this be known? How do you know that there are other life forms when you are not perceiving them?

    Well I can raise a question about any old thing I want. Perhaps mathematical truths are only true when a conscious being considers their truth value. But as with your "simple question", unless there is a reason to motivate considering the question as being true or at least plausible, it seems like idle speculation. And that you seem to accept that objects exist when perceive would entail some kind of relationship between existence and perception if we wish to raise a question about if they exist unperceived.MindForged

    The first thing to note is that questions aren't true or false, plausible or implausible. Only propositions are, as I've always understood the words 'true' and 'plausible'. Second, the question I raise is hardly ridiculous. Is there any reliable way to tell that things exist when unperceived? If there isn't, then the belief that things exist unperceived is sheer guess work. The question itself isn't the idle speculation. Rather, a failure to answer the question shows that the belief in unperceived existence is idle speculation.

    Lastly, yes, I agree that some objects exist when perceived. Hold up a piece of paper in front of your face. There is something that exists at the moment when you are perceiving it. But that doesn't settle the question of whether it exists unperceived.

    The fact that you exist necessarily implies that everything that is outside you exists since it is something that is not you, and hence it is. The same applies to everything that you can perceive. That is, the fact that a paper sheet exists, which you are able to prove through your sense-perception, implies that everything outside the limits of the paper sheet exists, for what is outside the paper sheet is not the paper sheet, and thus it is.Daniel

    Agreed.

    Therefore, even if you stop perceiving the paper sheet, what is not the paper sheet, ie. you and everything else that is not you or the paper sheet, by existing, causes the paper sheet to maintain its state of existence, for the paper sheet can only be that, a paper sheet. If it were the case that as soon as you stoped perceiving an object it would stop existing or it would exist in some other way, the change in the state of existence of the object would necessarily cause a change in your state of existence and in the state of existence of everything you are now perceiving. However, because this is not the case, it is same to assume that the contrary is what is real. Let me know what you think.Daniel

    Consider the paper case again. I hold a piece of paper in front of my face. At this moment, as I am perceiving it, it exists. Now suppose that I put the paper in a drawer and leave the room. Does the paper exist now? Why couldn't the paper cease to exist the very moment that I close the drawer and can no longer see it? You say that this would cause a change in me and what I am currently perceiving. Why would it? When I close the drawer I go into another room and am now looking at a bed. Why would things be any different if the paper ceased to exist when I stopped looking than if it continued to exist in the drawer. It seems that regardless of whether the paper exists or not, I will be perceiving a bed.

    Best,
    PA
  • MindForged
    731
    The first thing to note is that questions aren't true or false, plausible or implausible. Only propositions are, as I've always understood the words 'true' and 'plausible'. Second, the question I raise is hardly ridiculous. Is there any reliable way to tell that things exist when unperceived? If there isn't, then the belief that things exist unperceived is sheer guess work. The question itself isn't the idle speculation. Rather, a failure to answer the question shows that the belief in unperceived existence is idle speculation.

    You're being too pedantic. Obviously questions aren't truth-apt, I was referring to the proposition to which your question was about: Objects either existing when unperceived or failing to exist when unperceived.

    It isn't guesswork. I'll repeat: Do you think objects exist when perceived? Your next bit indicates you do so I'll continue after quoting it, because I may not have been clear what I've been driving at:

    Lastly, yes, I agree that some objects exist when perceived. Hold up a piece of paper in front of your face. There is something that exists at the moment when you are perceiving it. But that doesn't settle the question of whether it exists unperceived.

    Ok, so you agree objects exist when perceived and your question is if they exist unperceived. The only way this question can be interesting beyond idle speculation is if there is a relation between "perceiving a thing" and "that thing exists". Now why is this the case? Well, if you agree it exists when perceived, we have justification for believing the thing exists. After all, as you said, we perceived the thing in question. If I then ask "But does it exist when I'm not perceiving it?", I have to be making the following assumption:

    "There is a relationship (causal presumably) between perception and existence. Perception brings a thing into existence."

    Because otherwise what is the connection between not being perceived and not existing? No one says "Oh you weren't considering that maths problem so the conclusion of the problem doesn't exist", because that seems like a non sequitur. What do those 2 things have to do with each other. To just state it plainly: Why should I think objects don't exist when not perceived given that I accept they exist when I do perceive them? Perceiving them gives evidence that the objects at least existed at that time. But does it therefore mean that not perceiving them lends justification to the idea that they don't exist otherwise?

    If you say that we need a reason to think they continue to exist, I don't know how we require further justification than that they did exist when we perceived them unless you think perception brings objects into being. Maybe I'm missing something, because this seems like pure speculation.
  • PossibleAaran
    243


    Perceiving them gives evidence that the objects at least existed at that time.MindForged
    Yes it does.

    But does it therefore mean that not perceiving them lends justification to the idea that they don't exist otherwise?MindForged

    No it doesn't, and I would never make this inference. That is, the fact that an object, O, exists when perceived by me does not entail that O does not exist when unperceived. The former does not even make it likely that O does not exist when unperceived. So, I am not assuming that 'perception brings a thing into existence'. I am not assuming the opposite either.

    But even given this, there is still a further question about whether O exists unperceived or not. Either it does or it doesn't, and the fact that it exists when perceived doesn't entail that it also exists unperceived. It might be, for all we have said so far, that O exists when I perceive it but the moment I stop perceiving it, it ceases to exist. I am not assuming that this is true, and so I am not 'idly speculating'. What I am saying is that this has not been ruled out by anything we have said so far. You have not suggested any reliable method by which we could determine whether something exists when unperceived. You have suggested that some things exist while they are being perceived, and I have agreed with you on that. You then seem to think that somehow it just follows that they exist when unperceived as well. It does not follow, unless there is some reliable way to establish that these things don't just disappear from the world when unperceived.

    Is it 'idle speculation' to insist that we reliably establish the things that we believe? As opposed to simply accepting things with no basis. If so, then I suppose I am an idle speculator.

    Best,
    PA
  • Daniel
    458
    Well consider it this way, before you exist, it must be possible for you to do so, otherwise you would not exist. This possibility seems to be governed by a set of laws from which, I believe, the fact that everything must be a particular thing in order to exist is the most important and complicated one. Thus, for you to be able to exist, you must be you a nothing else. You cannot be two different things, either you are A or B, but you cannot be A and B; in other words, you cannot be two units, or two particulars. This simple fact, as I said before, proves the existence of other particulars outside you, for they are not what you are. However, they are not what you are because you exist, or you are not what they are because they exist, or you are what you are because they are what they are and they are what they are because you are what you are. So, it seems that everything that exists at a particular moment is able to exist because it shares its existence with other existing entities.So, If I am at this moment holding a paper sheet, according to my argument, I exist because that paper sheet also exist (this not being the only reason of my existence, off course, but only one of the conditions; for me to exist, everything that exists with me must exist, as well) and vice versa. To assume that when I stop perceiving the sheet of paper it stops existing would be the same as to assume that that which is outside the boundaries of my body changes when I do not perceive it. However, because that which is outside me shares a limit with me, for it is not what I am, if that which is not me changes, I should also change. Because I am constant, or at least my matter is, I can assume that even though I do not perceive, at all times and entirely, that which is outside me, it exists in a single state. So, that paper sheet will always exist in the condition the last action applied on it left it in. Please let me know what you think. Also I want to ask you a question: what would cause something to stop existing when not being perceived and come back into existence when sensed again?
  • MindForged
    731
    No it doesn't, and I would never make this inference. That is, the fact that an object, O, exists when perceived by me does not entail that O does not exist when unperceived. The former does not even make it likely that O does not exist when unperceived. So, I am not assuming that 'perception brings a thing into existence'. I am not assuming the opposite either.

    You'd have to be assuming that because otherwise there's no reason to suggest they do not exist when not perceived. If we know an object, O, exists when perceived, we know it at least existed. If you question its persistence sans-perception, the only way that can be the case is if perception causes existence. I don't see how you're not assuming that; it's the only possible way for the contrary to be true (unless things just happen randomly, I suppose).

    But even given this, there is still a further question about whether O exists unperceived or not. Either it does or it doesn't, and the fact that it exists when perceived doesn't entail that it also exists unperceived. It might be, for all we have said so far, that O exists when I perceive it but the moment I stop perceiving it, it ceases to exist. I am not assuming that this is true, and so I am not 'idly speculating'. What I am saying is that this has not been ruled out by anything we have said so far. You have not suggested any reliable method by which we could determine whether something exists when unperceived. You have suggested that some things exist while they are being perceived, and I have agreed with you on that. You then seem to think that somehow it just follows that they exist when unperceived as well. It does not follow, unless there is some reliable way to establish that these things don't just disappear from the world when unperceived.

    My point is as follows. Take the following statements:

    1) X is perceived, so X exists
    2) X is no longer perceived
    3) X either continues to exist or it fails to continue existing

    If perceiving it is grounds for saying it exists, good. Why should one question if it exists otherwise? Even if you're just asking a question, it doesn't matter. Questions can import false assumptions as much as a direct statement can. In this case, why should the notion that it stops existing when unperceived be taken seriously? After all, if perception does not cause existence, and we know the thing exists because we perceived it, there seems to be no grounds from which to raise the idea that the object stops existing when unperceived. We justified believing "O" exists by our perception, we didn't justify the notion that "O" exists only when we perceived it.

    I just mean to say, it doesn't see m like we require a reason to answer "they exist independent of perception" unless we are already assuming that perception plays a role in an object existing or persisting in its existence. And many many people would likely dispute that notion (for many objects, anyway).
  • PossibleAaran
    243
    Its true that I am what I am because everything else is not me. But it isn't true that nothing outside of me can change without me changing. In fact, this happens all of the time. When someone in India dies, do I - a person in the UK - change? Surely not. But then, it will not follow that if the paper ceased to exist I would change.

    You'd have to be assuming that because otherwise there's no reason to suggest they do not exist when not perceived. If we know an object, O, exists when perceived, we know it at least existed. If you question its persistence sans-perception, the only way that can be the case is if perception causes existence. I don't see how you're not assuming that; it's the only possible way for the contrary to be true (unless things just happen randomly, I suppose).MindForged

    If 'assuming' means, 'assuming that it is true', then I am not doing that. We know that O exists at the moment, M1, when we are perceiving it because we are perceiving it at M1. But what about a moment, M2, when it is not perceived? Does O exist then? Here is a hypothesis which is completely compatible with what I perceive at M1:

    (H) O does not exist at M2.

    Nothing about what I perceive at M1 entails that H is false. You insist that I must be assuming that something is true. You say:

    the only way that can be the case is if perception causes existence. I don't see how you're not assuming that; it's the only possible way for the contrary to be true (unless things just happen randomly, I suppose).MindForged

    I am not assuming that perception causes existence. For all I have said, it might be that when I perceive O, God instantly causes O to exist and when I look away, God destroys O. I am not saying this is true. I am saying it is compatible with everything that I perceive when I perceive O. It might also be that when I perceive O, some how this act of perceiving causes O to exist. I am not saying this is true. I am saying it is compatible with everything that I perceive when I perceive O.

    We justified believing "O" exists by our perception, we didn't justify the notion that "O" exists only when we perceived it.MindForged

    This isn't accurate. By perception, you can establish that O exists at the time at which you are perceiving it. You cannot establish merely by perceiving O at moment M1 that O exists at M2 when you aren't perceiving it. That O exists at M2 when you aren't looking just isn't part of what you can see at M1.

    there seems to be no grounds from which to raise the idea that the object stops existing when unperceived.MindForged

    What about the hypothesis that God causes O to exist and when I look away, God destroys O? What about the hypothesis that it is a law of nature that whenever we look in a certain place, O is created, and whenever we look away, O is destroyed? I am not assuming that either of these are true. I am saying that they are compatible with everything you perceive when you perceive O, and you have given no account as to how they can be reliably rejected.

    Best,
    PA
  • Wayfarer
    22.3k
    I think Kant’s distinction between empirical realism and transcendental idealism is useful in this context. In simple terms, this allows for common-sense realism when it comes to the existence of unperceived objects, but without loosing sight of the manner in which everything can be said to ‘conform to the understanding’ of the mind.

    Here's a passage in Magee's book on Schopenhauer which discusses this point:

    'Everyone knows that the earth, and a fortiori the universe, existed for a long time before there were any living beings, and therefore any perceiving subjects. But according to Kant ... that is impossible.'

    Schopenhauer's defence of Kant on this score was [that] the objector has not understood to the very bottom the Kantian demonstration that time is one of the forms of our sensibility. The earth, say, as it was before there was life, is a field of empirical enquiry in which we have come to know a great deal; its reality is no more being denied than is the reality of perceived objects in the same room.

    The point is, the whole of the empirical world in space and time is the creation of our understanding, which apprehends all the objects of empirical knowledge within it as being in some part of that space and at some part of that time: and this is as true of the earth before there was life as it is of the pen I am now holding a few inches in front of my face and seeing slightly out of focus as it moves across the paper.

    This, incidentally, illustrates a difficulty in the way of understanding which transcendental idealism has permanently to contend with: the assumptions of 'the inborn realism which arises from the original disposition of the intellect' enter unawares into the way in which the statements of transcendental idealism are understood.

    Such realistic assumptions so pervade our normal use of concepts that the claims of transcendental idealism disclose their own non-absurdity only after difficult consideration, whereas criticisms of them at first appear cogent which on examination are seen to rest on confusion. We have to raise almost impossibly deep levels of presupposition in our own thinking and imagination to the level of self-consciousness before we are able to achieve a critical awareness of all our realistic assumptions, and thus achieve an understanding of transcendental idealism which is untainted by them.

    Bryan Magee Schopenhauer's Philosophy, Pp 106-107
  • Marchesk
    4.6k
    How do I know that this piece of paper still exists when I put it away in my desk and leave the room?PossibleAaran

    Because it's there when you reenter the room and open the desk. If you doubt that, you can set a camera to record a video or snapshots of the paper while you're away. And from there, any scientific experiment for determining the existence of the paper in your absence would show it was still there.

    You could set up some indirect domino rube goldberg scenario to trigger a bunch of events if the paper is still there after you've left the room. Which ties into what holds the world you perceive together when you're not perceiving it. If you look up at the sky, is the ground still holding you up? Does your heart still pump blood while you're not aware of it beating? Does the back of your head exist when nobody's looking at it?

    How far do you want to take the skepticism? Because it can go all the way to the current perception for me right now, and leave everything else as unknowable.
  • Wayfarer
    22.3k
    The trusty old Samuel Johnson refutation.
  • Daniel
    458
    "Its true that I am what I am because everything else is not me. But it isn't true that nothing outside of me can change without me changing. In fact, this happens all of the time. When someone in India dies, do I - a person in the UK - change? Surely not. But then, it will not follow that if the paper ceased to exist I would change."

    When you suppose that the paper stops existing when not being perceived, do you mean that the atoms that form the paper disperse so that they are not shaped in the form of paper anymore or do you mean that the atoms stop being atoms and do not exist anymore?
    I am assuming that when you say that something stops existing you mean that the atoms that form that something stop existing, they are no more. When you say that someone in India dies, its atoms do not stop existing, they just assume another organization. However, if they stoped existing, everything would necessarily change since you are literally taking something out of existence.
    Now, if you mean that the atoms that form something change their organization in space when you are not looking at such something, an action should be causing such change, and such action should be absent when you look at such something again, or the other way around. If this is the case, what do you think is causing such change?. Also, I believe this action should be an action that acts only on that which you do not see but does not act on that which you do see, or the other way around. Therefore, if you were the paper, such action should be acting on what is now your body (from the point of view of the paper) when you are not perceving the paper and should stop acting on your body when you hold the paper. So what I am trying to say is that: if the paper dissapears when you are not perceiving it you should also dissapear relative to the paper, dont you think? However, your shape remains constant.
    Now, if you mean that something literally stops existing just because we are not looking at it, I do not believe, and I gave you the reason why this is hardly probable.
  • Marchesk
    4.6k
    The trusty old Samuel Johnson refutation.Wayfarer

    With some science and Heidegger thrown in. A big part of the perceived world is the interdependence of all the things we perceive. For example, how is it that I stay warm on a sunny day while I'm not aware of the sun? If the sun's not there because it's not being perceived, then what keeps me warm?

    Is it coherent to say that you can have a perception of small part of the world without the rest of it existing to support it, including the body that's doing the perceiving?

    Can I have a visual perception while my eyes don't exist (because nobody's perceiving them)? I don't actually see my eyes when I'm looking, unless there's a reflecting surface.
  • Marchesk
    4.6k
    What about the hypothesis that God causes O to exist and when I look away, God destroys O? What about the hypothesis that it is a law of nature that whenever we look in a certain place, O is created, and whenever we look away, O is destroyed?PossibleAaran

    Let's say that when nobody is observing the rest of the universe, all that matter is destroyed. So you get in a car while nobody is doing astronomy, and the driver steps on the brakes. What happens? Do you feel the rest of the universe opposing your change in motion, or just the Earth and Sun and maybe Venus if it's up?
  • Marchesk
    4.6k
    It might be, for all we have said so far, that O exists when I perceive it but the moment I stop perceiving it, it ceases to exist. I am not assuming that this is true, and so I am not 'idly speculating'. What I am saying is that this has not been ruled out by anything we have said so far. You have not suggested any reliable method by which we could determine whether something exists when unperceived.PossibleAaran

    Here's another related way to go about this. Has anyone died from something unperceived? Yes, quite often. One example would be going on a hike and being killed by a falling rock. The hiker may not have seen or heard the rock.

    Another would be dying from some disease, particularly in the past or places without access to medical equipment. You get sick and die from something nobody perceives. How does that work if the microbes, cancer, etc. doesn't exist?

    What does it even mean to get sick if the cells in your body don't exist? If the organs aren't there, because nobody perceives them? Are you just a shell secreting mucus and blood?

    Do you poop with no intestines? Did that food disappear without being digested? Will you really starve if you don't see food ever again? Why would that be?
  • Rich
    3.2k
    This is compatible with everything ceasing to exist when no one is perceiving it, so how does this support the view that things exist unperceived?PossibleAaran

    No. It is there (possibly) only hasn't been conceived by the mind. If course, new stuff is being created all the time.

    How can this be known? How do you know that there are other life forms when you are not perceiving them?PossibleAaran

    By observing their actions such as dogs reacting to higher frequency whistles or homing pigeons.
  • Wayfarer
    22.3k
    Is it coherent to say that you can have a perception of small part of the world without the rest of it existing to support it, including the body that's doing the perceiving?

    Can I have a visual perception while my eyes don't exist (because nobody's perceiving them)? I don't actually see my eyes when I'm looking, unless there's a reflecting surface.
    Marchesk


    Russell reports that G E Moore once mused 'do the train wheels cease to exist when everyone is inside the train?' And that is exactly the way you're seeing the question.

    I think the issue is (and we've been talking about this same question for years now) is this: that you're taking a scientific view of a philosophical question. The scientific naturalist will assume that the world 'exists anyway' - that is precisely what natural philosophy does, it 'assumes nature'. It has stepped away from a metaphysical analysis of the nature of knowledge and experience, and wants to understand (and more importantly measure) the objects of experience and how they are related.

    But the whole question of 'hey wait a minute, how do I know what I think I know?' is not actually the kind of question that the natural scientist asks. But because nowadays because of the influence of science on culture, we're immersed in that naturalistic view, so we misunderstand what kind of question we're actually discussing.

    Those who are really able to 'deconstruct' or question the nature of experience in such a way have been in some sense 'through the looking glass' (speaking of which, I really think Lewis Carroll was wise to all this.) But for those who haven't been 'through the looking glass', the question can only be dealt with from the perspective of scientific realism. I don't really know what to do to break out of this particular impasse, but strongly suspect it is not something which is amenable to a solution by Forum conversations. :)
  • andrewk
    2.1k
    How do I know that this piece of paper still exists when I put it away in my desk and leave the room?PossibleAaran
    You probably won't know, because of the crudity of human sensory organs, but in theory you could, in the same way as we know about a black hole: by its interaction with other things. A paper sheet in another room interacts with the desk drawer containing it, which interacts with the desk, which interacts with the floor and air, which interact with the walls of the closed room, which interact with the air outside the room, which interacts with you,

    There would be tiny differences in the patterns of air movement around you if that piece of paper were not in that closed desk in the closed room. Your naked senses may not be enough to measure that but, at least in theory, if you had sensitive enough measuring equipment, you could detect the difference.

    This is writ large in Wayfarer's / Russell's / GE Moore's example here (). If the train wheels ceased to exist once nobody was looking at them, the passengers would hear and feel an almighty jolt as the carriages they were in suddenly dropped onto their axles.

    This response may not work for astronomical objects outside the observable universe, because of the expansion of the universe. But that's a somewhat different discussion.
  • Marchesk
    4.6k
    But for those who haven't been 'through the looking glass', the question can only be dealt with from the perspective of scientific realism.Wayfarer

    I'm asking whether it's coherent to think that only the thing I'm experiencing right now exists given how that thing or part of the world is interdependent with the world in all sorts of ways. This also applies to me. I see, but what about the eyes I see with which I'm not perceiving?

    You don't even need to bring science in to the equation. You can just note the interdependence of everything in the world from a phenomenal point of view.
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