If you have toothache, what good is the idea that it is an illusion?

The proposition is, without Ockham's razor, the chances that this is reality is the same as it being an illusion. — Down The Rabbit Hole

This comes up from time to time. But if this were so, that is, if everything you see and experience is an illusion, then what happens when you have what people normally call an "illusion"? Would this be an illusory-illusion or an illusion-illusion?

From the outset, you need to have an idea of what an illusion is so you could say when it happens. Otherwise, the concept doesn't seem to have any meaning.

I am going to a full dementia comparison on this one.

So the fully involved dementia patient is solidly in their own created reality; they see the little people dancing, they hear the music playing, they smell the food at the buffet. They are immersed in this reality. To them it is not created, it is fact. It disturbs us, not because the patient is distressed, or in pain, but because it is a reality that has nothing to do with us and the only way we can influence it is to destroy it through the application of drugs, enough to reduce the patient to a quasi-nonfunctioning state. We can't even confirm that the state no longer exists, however, as the patient can no longer communicate with us due to the amount of drugs we have given them, we feel better as our reality is not challenged.

Comforting eh?

We could be completely involved in an illusion; the last fleeting ideas of a dying mind. Really, since we are all in it, who would know?

The proposition is, without Ockham's razor, the chances that this is reality is the same as it being an illusion. — Down The Rabbit Hole

Is there any way to determine, at least in principle, whether or not we live in an illusion as opposed to what you call "reality?" If not, then there is no difference between the illusion and reality. If reality is an illusion, the illusion is reality.

...there is equally no evidence this is reality... — Down The Rabbit Hole

...right up until the truck hits you.

What this shows is that you have lost track of what is to count as evidence.

If you have toothache, what good is the idea that it is an illusion? — SolarWind

Yes, I wouldn't like the illusion of a toothache either.

This comes up from time to time. But if this were so, that is, if everything you see and experience is an illusion, then what happens when you have what people normally call an "illusion"? Would this be an illusory-illusion or an illusion-illusion? — Manuel

A "dream within a dream". Have you seen the film Inception?

We could be completely involved in an illusion; the last fleeting ideas of a dying mind. Really, since we are all in it, who would know? — Book273

Yes, even when you're in a dream/nightmare it seems real at the time. There is no reason to believe we are in reality, other than it is the simplest explanation.

Is there any way to determine, at least in principle, whether or not we live in an illusion as opposed to what you call "reality?" If not, then there is no difference between the illusion and reality. If reality is an illusion, the illusion is reality. — T Clark

I think there would have to be something built into the illusion that proves it is an illusion.

I think it's reasonable to call the original place that hosts us reality.

...right up until the truck hits you.

What this shows is that you have lost track of what is to count as evidence. — Banno

None of our experiences can be trusted as evidence that this is reality as those experiences would be the same if this was an illusion. — Down The Rabbit Hole

None of our experiences can be trusted as evidence that this is reality as those experiences would be the same if this was an illusion. — Down The Rabbit Hole

Being hit by a truck is the same if it were real or an illusion? How do you know that? Wanna give it a test?

A "dream within a dream". Have you seen the film Inception? — Down The Rabbit Hole

Sure. Fun movie. But I don't know if there's a way to test one of the fundamental ideas in that film: that a dream within a dream lasts longer the more "dreams down" you go. Maybe it happens, maybe not.

But the question would be: who's the dreamer? Is it a super intelligent AI? Is it "God"? Or is it the universe? If it's the AI, I'd have to say that I think the probabilities of that being the case are so impractically low, that I'd almost say it's impossible.

If it's God, then you'd have to give me some of his/her characteristic to get a better idea.

If it's the Universe, well, I'm familiar with Bernardo Kastrup's idealism, it's quite interesting and it's a refreshing perspective. It solves some problems, but I think he's wrong.

I don't think the universe is "conscious" in any manner that remotely resembles what we have in mind when we use that word.

So you'd have to tell me a bit about the dreamer or who is causing the illusions.

None of our experiences can be trusted as evidence that this is reality as those experiences would be the same if this was an illusion.
— Down The Rabbit Hole

Being hit by a truck is the same if it were real or an illusion? How do you know that? Wanna give it a test? — Tom Storm

Our experience as to its realness is the same. Because, by definition, we wouldn't be able to tell an illusion from reality.

I think Ockham's razor might make it marginally more likely that we're living in reality. Though, even if it was 50/50 I would prefer to err on the side of caution, and avoid any trucks.



You cannot reliably work out the probability of the illusion's origin, while in the illusion. You would need the illusion to be a copy of reality.

Ockham's razor aside, there is no reason to believe that this is reality over an illusion.

Our experience as to its realness is the same. Because, by definition, we wouldn't be able to tell an illusion from reality. — Down The Rabbit Hole

That's the commonly held view.

Before I was shot, I always thought that I was more half-there than all-there - I always suspected that I was watching TV instead of living life. Right when I was being shot and ever since, I knew that I was watching television.

Andy Warhol on nearly being killed.

You cannot reliably work out the probability of the illusion's origin, while in the illusion. You would need the illusion to be a copy of reality.

Ockham's razor aside, there is no reason to believe that this is reality over an illusion. — Down The Rabbit Hole

It's less probable, there are less step involved in thinking that this is "normal" reality vs. an illusion. If you speak of representations caused by stimulations of "things in themselves", then I'd agree.

If you have in mind some other reality, or some other origin, I don't see why there are good reasons to accept such a view.

Who cares? It's real enough.

It's less probable, there are less step involved in thinking that this is "normal" reality vs. an illusion. — Manuel

(Assuming that our rules of logic are the same in the illusion and reality) I think that's the only reason reality is more probable - because there are less steps involved.

If a doctor told me that I have a terminal illness with a standard 50% survival rate but on this occasion it would be more because "there are less steps involved". This wouldn't be enough for me to believe that I wasn't going to die from it. Why should it be enough for us to believe that we are in reality?

Who cares? It's real enough. — khaled

Yes it's certainly real enough.

(Assuming that our rules of logic are the same in the illusion and reality) I think that's the only reason reality is more probable - because there are less steps involved.

If a doctor told me that I have a terminal illness with a standard 50% survival rate but on this occasion it would be more because "there are less steps involved". This wouldn't be enough for me to believe that I wasn't going to die from it. Why should it be enough for us to believe that we are in reality? — Down The Rabbit Hole

I don't understand what you are getting at with the analogy. Illusion-based world or not, you'd still have 50% chance to die. The "less stepped involved argument" was merely an illustration of one problem:

Could the world be an illusion? Sure. But this world could also be the dream of the third turtle down, in a world in which there are turtle's all the way down. That could be true too. Or this world could be the result of God's suicide and we are his corpses as we head the way to total annihilation of the universe, some have said this, using interesting reasoning.

But that's the point. It could be all that and much more. But why add to our situation if something can be satisfactorily stated without recourse to further complications? I don't see how postulating an illusion can help clarify the status of reality.

Perhaps you could explain what is made easier by such a postulation.

@Down The Rabbit Hole

I don't entirely disagree with you, but I think there is an important distinction that needs to be made when trying to determine what is true. You seem to be coming from the direction of, true until proven false. I think @Manuel correctly comes from the opposite direction of false until proven true. However, I will make one precondition to this rule. At the end of any claim, a person must implicitly mean "so far as I know" because, of course, no one can know what they do not know. That is to say, some things are beyond our current knowledge, or beyond our capacity to know, and we cannot know what these things are. If you knew what they were, then you could no long say that you don't know them.

There is not any evidence, so far as I know, to support the view that our world is an illusion. The only reason we even believe it is a possibility is because "we don't know what we don't know," it is a question that we can neither prove or disprove and therefore it could be true. However, how can you attribute any sort of likelihood to such a thing? Likelihoods are based on evidence. When there is no evidence, where does that leave us? Certainly not at a 50/50.

I could say, for example, I do not know if all crows are black, but I cannot say that some crows are purple. One is a statement that leaves room for a truth that I am unaware of, the other is a statement that asserts something that I do not in fact know to be true. I can only say the first in so far as I know I am not omniscient, I cannot say the second with any credibility.

I think Manuel correctly comes from the opposite direction of false until proven true. However, I will make one precondition to this rule. At the end of any claim, a person must implicitly mean "so far as I know" because, of course, no one can know what they do not know. That is to say, some things are beyond our current knowledge, or beyond our capacity to know, and we cannot know what these things are. If you knew what they were, then you could no long say that you don't know them.

There is not any evidence, so far as I know, to support the view that our world is an illusion. The only reason we even believe it is a possibility is because "we don't know what we don't know," it is a question that we can neither prove or disprove and therefore it could be true. However, how can you attribute any sort of likelihood to such a thing? Likelihoods are based on evidence. When there is no evidence, where does that leave us? Certainly not at a 50/50. — Andrew F

Very well put. :up:

Exactly. We can easily come up with more and more scenarios in the blink of an eye. But this doesn't clarify the situation, unless an argument is given to the effect that certain things make more sense on the supposition that X is the case or is likely correct. So evidence for any of these views must be substantial for them to gain plausibility. Or, absent evidence, good reasons.

The "so far as I know" should be taken as a given if the discussion is attempting to be honest, which I have no doubt is the case here.

But then there's something here which seems obvious but has not arisen yet:

What is meant in this case by "illusion"? Does it mean "not real and/or imaginary" or does it mean based on a simulation of some kind or does it mean something else entirely? If no further clarification is articulated, I'm only left with the common meaning of the word.

I don't understand what you are getting at with the analogy. Illusion-based world or not, you'd still have 50% chance to die. The "less stepped involved argument" was merely an illustration of one problem: — Manuel

I was comparing the chances of this being reality to that of surviving the terminal illness.

"Less steps" aside, there is the same amount of evidence that this is reality as it being an illusion (zero).

So if the doctor said that you had a better chance than the standard 50% survival rate, solely on the basis that there are less steps involved in surviving, would this be enough for you to believe that you are not going to die? If not, it's equally not good enough reason to believe we are experiencing reality.

However, an illusion wouldn't have to share the same rules of logic as reality. The "less steps" argument could mean nothing in reality.

But that's the point. It could be all that and much more. But why add to our situation if something can be satisfactorily stated without recourse to further complications? I don't see how postulating an illusion can help clarify the status of reality. — Manuel

Yes, it's all could be. I suppose it helps us see that many of our assumptions may not be as likely as we think they are, and we should be open to the idea that our foundational beliefs could be wrong.

Likelihoods are based on evidence. When there is no evidence, where does that leave us? Certainly not at a 50/50. — Andrew F

It does if there is an equal amount of evidence. There is no evidence that this is an illusion, but there is also no evidence that this is reality (our experience as to its realness is not evidence, as it would be the same in an illusion).

I was comparing the chances of this being reality to that of surviving the terminal illness.

"Less steps" aside, there is the same amount of evidence that this is reality as it being an illusion (zero).

So if the doctor said that you had a better chance than the standard 50% survival rate, solely on the basis that there are less steps involved in surviving, would this be enough for you to believe that you are not going to die? If not, it's equally not good enough reason to believe we are experiencing reality.

However, an illusion wouldn't have to share the same rules of logic as reality. The "less steps" argument could mean nothing in reality. — Down The Rabbit Hole

If a doctor said I have a better chance of surviving if I do what? If I do something that takes less steps than doing what is usually done? Is that more or less what you are getting at? He'd have to give some evidence that the option with less steps actually improves my odds of surviving. If he doesn't then that argument carries no force.

But that's the point, can you give me any evidence that an illusion makes some aspects of reality more plausible?

The proposition is, without Ockham's razor, the chances that this is reality is the same as it being an illusion. — Down The Rabbit Hole

That equation of Real and Illusory may be true in one sense, but it seems to be based on a loose use of terminology. I prefer to make a comparison between Real and Ideal. That's because everything you "know" is a mental construct, a Subjective Idea, not a direct perception of Objective Reality. Kant's Transcendental Idealism used the terms Phenomenon and Noumenon to describe what we perceive (appearances) and what we imagine (noumena) to be really out there in the world.

A more recent formulation of the same notion is cognitive psychologist Donald Hoffman's theory, expressed in The Case Against Reality, that Evolution, in the interest of fitness, filtered-out the messy complexities of "Reality" from human observers -- like the smoke & mirrors of a stage magician -- by reducing our incoming sensory information to simple symbolic Icons (mental imagery = Ideality). In that case, the subjective illusion (phenomenon) is all we ever know about the objective ding an sich (noumenon). His "Fitness Beats Truth theorem is a modern version of the ancient notion of Maya, the veil of illusion".

Fortunately, the human mind has developed a method to get closer to the underlying truth : the Scientific Method (including Okham's Razor). It's still not direct access to Reality, but it allows us to peek behind the curtain to see the mechanical dials and levers that produce the iconic mental images that we naively accept as True Reality. :cool:


Kant: Experience and Reality :
Phenomena are the appearances, which constitute the our experience; noumena are the (presumed) things themselves, which constitute reality. ... Since the thing in itself (Ding an sich) would by definition be entirely independent of our experience of it, we are utterly ignorant of the noumenal realm.
http://www.philosophypages.com/hy/5g.htm

Reality is not what you see :
In his doctrine of Transcendental Idealism, 18th century philosopher, Immanuel Kant argued that our perception of reality is limited to constructs created in our own minds to represent the invisible and intangible ultimate reality that he mysteriously labeled “ding an sich” [things-in-essence, as opposed to things-as-we-know-them]. In other words, what we think we see, is not absolute reality but our own ideas about reality.
http://bothandblog6.enformationism.info/page21.html

Is Reality a Cosmic Simulation? :
“Musk is just one of the people in Silicon Valley to take a keen interest in the “simulation hypothesis”, which argues that what we experience as reality is actually a giant computer simulation created by a more sophisticated intelligence. If it sounds a lot like The Matrix, that’s because it is.”
http://bothandblog4.enformationism.info/page23.html

Reality is a Theory :
“Let us remember that our knowledge of the world begins not with matter but with perceptions. I know that my pain exists, my “green” exists, and my “sweet” exists. I do not need any proof of their existence, because these events are a part of me; everything else is a theory.” ___Andre Linde, theoretical physicist
http://bothandblog5.enformationism.info/page15.html

Reality is Ideality :
Physics is ultimately Meta-Physics
http://bothandblog5.enformationism.info/page17.html

If a doctor said I have a better chance of surviving if I do what? If I do something that takes less steps than doing what is usually done? Is that more or less what you are getting at? — Manuel

Yes.

He'd have to give some evidence that the option with less steps actually improves my odds of surviving. If he doesn't then that argument carries no force. — Manuel

Ahh, but if we are in an illusion we have no evidence as to the steps that would be in the real world. So to make the thought experiment fair, all we have to rely on in both cases is the fact that there are fewer steps. If it isn't enough for us to believe that we're not going to die, why should it be enough for us to believe that we are in reality?

But that's the point, can you give me any evidence that an illusion makes some aspects of reality more plausible? — Manuel

No, all I can say is that the odds that we are in an illusion are similar to those that we are in reality. This is not a common view.

Ahh, but if we are in an illusion we have no evidence as to the steps that would be in the real world. So to make the thought experiment fair, all we have to rely on in both cases is the fact that there are fewer steps. If it isn't enough for us to believe that we're not going to die, why should it be enough for us to believe that we are in reality? — Down The Rabbit Hole

Ok. Let me try to put that in another way, otherwise I'm going to get confused. Either we are in an illusion or in reality. Let's assume we don't know which world we're in. In both cases illusion and reality, the doctor says I have 50% chance of dying in a week. That's fine. It would hold true of both cases.

Either we die in the illusion or we die in reality. The only meaningful difference I can extract from that is that if this were an illusion, I might wake up to reality. Or I might not and I'll still be in an illusion.

Is that possible? Sure. But I would make no attempts to verify such experiments in this world. And the only reason you've given so far, is that it's a possibility.

I only say that it's a possibility that either we are the dream of the third turtle down, in a world in which there are turtles all the way down. Or we are the rotting corpses of God, who choose to commit suicide because he thought death preferable to existence.

There's no reason to accept these arguments at all.

No, all I can say is that the odds that we are in an illusion are similar to those that we are in reality. This is not a common view. — Down The Rabbit Hole

Which is just as plausible as saying that we are a turtles dream or part of the corpse of God.

In both cases illusion and reality, the doctor says I have 50% chance of dying in a week. — Manuel

I think you misunderstand the move @Down The Rabbit Hole is making. He is using the analogy with the doctor to show the weakness of Ockham's Razor in his original post. Ockham's Razor was originally formulated as "entities should not be multiplied without necessity," but it is often used in metaphysics today as "simpler is better." If you are presented with two options that seem equally likely, in Rabbit Hole's example the options are living or dying from the terminal illness, you would not think that one is more likely than the other just because it is simpler (Ockham's Razor). In the same way, it does not seem like the simpler option when it comes to illusion or reality would be any more true just because it is simpler. I haven't mentioned Ockham's Razor yet because as Down The Rabbit Hole has pointed out it is not an immutable law and so it doesn't make much sense to appeal to it as such.

It does if there is an equal amount of evidence. There is no evidence that this is an illusion, but there is also no evidence that this is reality — Down The Rabbit Hole

Good point. Off the top of my head I can't come up with any reason to say that this is reality as opposed to a really good illusion, so the evidence for each is equally zero. However, zero evidence does not lead to likelihood or probability. It is not a 50/50, it is unknown/unknown. For example, what is the likelihood that there is a purple crow? Well, it is very hard to disprove the possibility of anything, let alone the possibility of a purple crow, but with no evidence for its existence you cannot quantify the probability of it existing. Granted, our world being reality or an illusion is a little different because one of the two options must be the case. However, the probability of each possibility is still entirely unknown.

That probably seems nit picky, but apart from that I really can't add anything else at the moment. I don't know of anything that would count as evidence in favor of our world being reality. I have been trying to put together some kind of common sense argument that takes world as reality as the default, but I'm thinking that may only be a pragmatic move.

I think you misunderstand the move Down The Rabbit Hole is making. He is using the analogy with the doctor to show the weakness of Ockham's Razor in his original post. Ockham's Razor was originally formulated as "entities should not be multiplied without necessity," but it is often used in metaphysics today as "simpler is better." If you are presented with two options that seem equally likely, in Rabbit Hole's example the options are living or dying from the terminal illness, you would not think that one is more likely than the other just because it is simpler (Ockham's Razor). In the same way, it does not seem like the simpler option when it comes to illusion or reality would be any more true just because it is simpler. I haven't mentioned Ockham's Razor yet because as Down The Rabbit Hole has pointed out it is not an immutable law and so it doesn't make much sense to appeal to it as such. — Andrew F

Sure, I see that. I mean, if we go straight to the point, I could say that the simplest explanation possible for everything is "strict" or "strong" solipsism, everything is a creation of me, this very moment. My immediate past, and the near future, don't exist. The only thing that exists is me and my projections.

Of course, this can be debated endlessly. Someone will say that such a view is not simple, as it assumes that I was the cause of Tolstoy and Beethoven and everything else. Surely there are many, many examples in which Ockham's Razor fails. It should be used, when it is sensible to use it. That varies by person to some extent.

I still don't think the illusion option follows. Let's put aside the "less steps" argument and just argue from plausibility alone. If it is true that this world being an illusion is just as realistic as assuming a "normal reality", then why should it not be the case that we aren't in a world in which we are the remains of a God who killed himself?

The point here, as I take it, is that such scenarios can be stipulated instantly and there are infinitely many scenarios one can imagine. So if this world is an illusion, it could also be heaven or hell or someone's dream. But then we postulate an infinite number of scenarios, as we have to, given this line of thinking.

We are left then, with an infinite number of alternative worlds and the real world. But then we are not considering one view (illusion) being as likely to be true as another view (we are in the real world).

Things looks like either we are in an infinite number of hypothetical worlds or in the real world. So it's not even that there's an equal chance of either being the case, there's an infinite number of options on one side and only one option on the other.

This makes the illusion argument look weak, I think.

Thanks for commenting.

@David Pearce was defending the view that our perception of reality is fundamentally different to reality in his thread, and of course Hoffman wrote a whole book putting the case. The difference is that in their argument we are assuming we are in reality, it's just our perception of it that's illusory.

I was thinking of getting Hoffman's book a while back, but the reviews were terrible.

I was thinking of getting Hoffman's book a while back, but the reviews were terrible. — Down The Rabbit Hole

The book is fine. I mean, I think it's good to put idealism back on the table. The main problem with the book has to do with him saying that science does not tell us about the nature of reality. But he relies on science to lead him to his idealism.

But I did not think the book terrible, even if it was not persuasive to me. You might like it, or not.

I was thinking of getting Hoffman's book a while back, but the reviews were terrible. — Down The Rabbit Hole

I suspect that the reviews you referred to were negative, due to the slightly New-Agey tone of his book. New Age guru, Deepak Chopra, was much more positive : “A masterpiece of logic, rationality, science, and mathematics. Read this book carefully and you will forever change your understanding of reality, both that of the universe and your own self.”

Personally, I am wary of some New Age notions that cross the line into Magic & Mysticism. But, what I most appreciate in Hoffman's book is the useful and meaningful metaphor of our subjective worldview as an "Interface", which represents ultimate reality via symbolic icons. I wouldn't call that an "illusion", but a pragmatic necessity due to the limited capacity of the human brain, which is still a work-in-progress. Anyway, I have no problem at all with combining Realism and Idealism into a single comprehensive belief system. :smile:

True Reality : Both Real & Ideal :
For empirical scientific purposes, those ideal aspects of the world can be safely ignored. But for theoretical personal reasons we have no other choice but to deal with the unreal.
http://bothandblog.enformationism.info/page30.html

Things looks like either we are in an infinite number of hypothetical worlds or in the real world. So it's not even that there's an equal chance of either being the case, there's an infinite number of options on one side and only one option on the other. — Manuel

Doesn't look likely we are in the real world then? :grimace:

The book is fine. I mean, I think it's good to put idealism back on the table. The main problem with the book has to do with him saying that science does not tell us about the nature of reality. But he relies on science to lead him to his idealism.

But I did not think the book terrible, even if it was not persuasive to me. You might like it, or not. — Manuel

Thanks.

A lot of the bad reviews might be people that don't agree with his conclusions. I don't think this is good reason for disliking a book though - I am happy with a book that is well written and challenges my worldview.

Thanks for coming back and providing some reassurance that I'm not going crazy :wink:

Doesn't look likely we are in the real world then? :grimace: — Down The Rabbit Hole

Well, there are few certainties (if any) in life, so there's no way to know for sure. But based on probability and plausibility, I think this is the "real" world. But as an idealist of sorts, take that with a grain of salt. :chin:

A lot of the bad reviews might be people that don't agree with his conclusions. I don't think this is good reason for disliking a book though - I am happy with a book that is well written and challenges my worldview. — Down The Rabbit Hole

:up:

Honestly, the one clear PR mistake Hoffman made, to my mind, was to put Deepak Chopra as the top blurb in the back of the book. At least that's how it was with the hardcover version of the book. It's fine if you think people ought to be open minded or don't find Deepak silly.

But having that name as the top comment will turn off many people who don't take Chopra seriously. This happens to include many of the people you'd want to get to take "conscious realism" seriously.

That one issue aside, the book is fine and mostly enjoyable.

...by definition, we wouldn't be able to tell an illusion from reality. — Down The Rabbit Hole

Then how is it that we happen to have these two distinct words?

There is a difference between being hit by a truck and having the illusion of being hit by a truck.