Is believing that an object that you’re staring at won’t suddenly pop out of existence justifiable or unjustifiable?

Question

For example, say you are sitting at a desk with a plastic water bottle upon it. You set a timer for 30 seconds and stare at the water bottle. As you are setting the timer, you say to yourself “It is guaranteed that this plastic water bottle won’t pop out of existence in these 30 seconds that I’m staring at it.” Is such a statement justifiable? Now, the only justification I can come up with is that we have never in our lives seen any object just pop out of existence, but obviously Hume and the problem of induction showed us that this is not a valid justification. Your thoughts?

Answer 1

It is justifiable to believe an object will not pop out of existence (or perception, as pointed out elsewhere), but you may not be right about it.

Because we can verify our belief against the experiences of ourselves and most other people in the world, it's a justifiable belief to hold that the object will remain in our perceptive field after just 30 seconds.

That said, it's not to say that it's necessarily a true belief. Something may indeed happen to the object depending on what material it's made out of, environmental circumstances, etc. that could cause it to 'not exist' in the same manner that it did when you started looking at it.

Answer 2

It would not "pop out of existence" but "out of perception" (which to some are the same thing). Some stage magicians are able to pull off such psychological tricks.

And of course, if the object never existed in the first place, it will pop away. I (and many others) experienced such phenomena in childhood, such as a ghost/demon invoked by fears and shadows and poor lighting, that vanished when I was grounded.

In one particular case I was confronted by a giant bat in the school library, about a metre tall, swaying from side to side. After an eternity the chaplain, who had been bent over a lower bookshelf, and who was wearing a creased black gown, stood upright.

I've been aware of this phenomenon when listening and reading too, when my mind predicts how the meaning will unfold, and auto-corrects as it happens. But sometimes, I am sure that a false interpretation may persist if I am distracted before the confusion has been resolved.

So let your bottle vanish – if it was an illusion. There is a great difference between perception and reality... which we can never quite reach.

Answer 3

It just comes down to how you want to define the concept of impossiblity.

One could take the position that the word is fairly useless because, being imperfect beings capable of error, we can never justifiably deem something "impossible".

One could take the position that only true logical impossibilities can be known to us imperfect beings. Perhaps we can know that something cannot both possibly have a property and not have a property at the same time and to the same extent, but not much else.

But we do in fact also label as "impossible" things that are truly inconsistent with our understanding of cause and effect. Unless you believe that we can deem nothing impossible or only deem that which is self-contradictory to be impossible, the concept extends to that which we justifiably believe to be physically impossible because it is inconsistent with physical laws we justifiably believe not to have exceptions.

Is believing that an object that you’re staring at won’t suddenly pop out of existence justifiable or unjustifiable?

Belief would not be a useful concept if we set such a high threshold for belief that we couldn't function in our daily lives. The amount of evidence or argument we need to support a belief is not really that high.

If Jeff tells me that he missed work yesterday because he was sick, I have no reason not to believe him, and I do believe him, then that belief is justified. Of course, I do accept that it could be wrong and I would be wise not to forget how strong and weak the evidence I have to support that belief is in case I encounter additional evidence later.

Answer 4

The answer to this question is essentially the same as that for "Certainty for the existence of tomorrow?". We can have no certain knowledge regarding the real world - hence there can be no guarantees, just uncertain knowledge with varying degrees of confidence.

It is not possible to be 100% certain of anything that is not a logical necessity, which includes all statements about the nature of physical reality. The quest for certain knowledge about the real world is fundamentally wrong-headed and it is disappointing that philosophy (at least at an amateur level) is still pursuing it. We can only have uncertain knowledge - best to become comfortable with that as it is all that is available.

There have been cosmological "phase transitions" before, e.g. the inflationary expansion of the universe. There is no reason why there may not be some other "phase transition" that we don't know about that could essentially destroy space and time as we know it. Unknown unknowns are always going to be a problem here and mean you can't be 100% certain.

If such a phase transition happens in the next 30 seconds, the water bottle will indeed disappear - but so will you, so you wouldn't be there to observe it anyway.

From a subjectivist Bayesian perspective, it is easy to justify high confidence that the bottle will still be there - common sense. We all have a shared experience of objects failing to spontaneously disappear, so it doesn't really need specific justification when it is obviously a reasonable belief. Why would you need more?

From an objectivist Bayesian perspective, you could start of with a beta(1,1) (i.e. uniform) prior on the probability of the bottle disappearing, reflecting complete uncertainty on the value of that probability. Then use Bayes rule to update that prior every time you perform the experiment, and you will end up with a Beta(1+d, 1+r) posterior distribution where d is the number of times you saw it disappear and r is the number of times it remained present. If you value the observations of intependent observers, then you could sum over their p and r values to get a more confident posterior more quickly.

Or you could take a modelling approach and consider how the bottle might disappear and calculate the probabilities according you your model. The model would then be the justification.

Answer 5

I assume OP is not asking about any kind of illusion, trick, magic, illness of the mind (psychosis etc.) but is specifically creating an experiment which is as everyday as possible. I.e., an experiment we witness with exactly the same result every day, everywhere around us: macroscopic objects do not usually spontaneously disappear, and if they do so, there is nearly always a plausible reason that is obvious. We are not talking about special cases like a magician's illusion, or some complex machinery whisking some object away so quickly that our brains cannot see it, or an optical illusion. Quite obviously he is not asking about a case where some person suddenly jumps up from behind his desk and takes the bottle away, or where the Sun suddenly goes supernova and obliterates the bottle. By design we are also talking about an event which is not a 75%/25% chance, but incredibly closer to (but of course never completely at) 100%/0%.

He is specifically formulating it as pop out of existence. Not "take away", "be gone after the 30s", "fallen off the table", "destroyed" or anything like that. Even the formulation of "pop out of existence" clearly invites the thought that this simply does not happen in our everyday experience.

So in the spirit of this assumption...

It is absolutely justifiable to assume that the object behaves as usual, in many variations of what "justified" could mean. Quoting SEP's entry on Justified True Belief, and checking which dimensions they have of different views regarding this:

• Internalists beliefe it would be justified: "if and only if believing that p is the attitude towards p that best fits S’s evidence, where the latter is understood to depend only on S’s internal mental states" (the evidence, after many experiments and including S's mental state, speaks for the expectation).
• Externalists do as well: "for example, process reliabilists think that justified beliefs are those which are formed by a cognitive process which tends to produce a high proportion of true beliefs relative to false ones" thinking it through, it is much more likely that a process view leads to the bottle still being there. Otherwise you'd need a process that somehow changes the result, and arguably the way the argument is set up, the everyday process seems most likely.
• Propositional justification "concerns whether a subject has sufficient reason to believe a given proposition" and certainly applies here, and...
• ... doxastic justification concerns whether a given belief is held "appropriately", and surely matches as well.

So while nothing is ever certain, and while it may be worthwhile to point OP to the Bayesian Epistemology/worldview, it seems abundantly clear that it is unnecessary to make OP's example more complicated than it is: it is justifiable to believe that the object will behave like it always does; exceptions notwithstanding.

Whether it is also true belief does not matter. OP is asking about justified belief, not full JTB knowledge here.

Answer 6

I'd be willing to bet you $1000 at 10-1 odds that it won't pop out of existence. The problem of induction says we can't prove it won't, but that doesn't mean we can't say which outcome is more likely. We can argue the semantics of what exactly constitutes a justified belief, but we know that in practice, if you accepted bets like that, I'd be the one to come out ahead. This provides us a very practical definition of "justified" under which the belief is quite well justified indeed.