If you ask me, radical skepticism subsumes the problem of collective hallucination: the Cartesian demon rules over all sensory perceptions, whether illusory or hallucinatory. The difference between the skeptic's illusion and a hallucination is like the difference between actually witnessing magic and dreaming that one is.

The principle of universal perception, as I see it, is already alert to the skeptic's universal doubt and collective hallucination is but a part of this doubt. What the PUP is mainly interested in is the private hallucination which we all know happens; after all if we begin to accept private hallucinations to be as real as is possible for the skeptic then, it would amount to making dreams of magic shows as legit as the actual magic itself.

To make the long story short, a collective hallucination is what the skeptic already assumes to be the case and is accounted for if only in the form of a meek capitulation to it. The private hallucination, however, is not part of our deal with reality for it's, as a worst case scenario, an illusion of an illusion, a double jeopardy so to speak.

It seems that out of habit, if nothing else, we regard what can be collectively perceived as something outside of us (objective) and what is perceived only by one or a few as inside of us (subjective).

This situation is probably one of the main reasons why people reconfigured their trust, leaning towards what I will loosely refer to as rationalism, something that can't be fooled by mere appearance in a manner of speaking.

"I'm hallucinating" is a very simple explanation — Echarmion

No because it is abnormal (using common sense alone, the normal is to not hallucinate), and so we would need to further explain the cause of that abnormality. In contrast, we don't need to further explain the existence of an oasis, as it is not abnormal.

while I am hallucinating, perhaps I am also hallucinating the people that agree with me. — Echarmion

Might as well believe that the whole world is an illusion, on the mere grounds that it is logically possible. But logically possible does not entail reasonable. For this, we appeal to further principles of reasonableness like Parsimony.

The bigger issue is that you haven't justified the principle of parsimony. Why is the less complex explanation closer to reality? Is reality obligated to be simple and parsimonious? — Echarmion

This discussion defends the PUP on the grounds of Parsimony, which is indeed assumed. I am hesitant to defend that here, with fear that I would need to defend the premises for Parsimony etc. All I will say for now is that it is a perfectly accepted scientific principle, and that the alternative (that more complex is more reasonable) leads to a reductio ad absurdum: Can't prove there is no teapot in space? Then we'll believe there is.

The reason we can use the parsimony as a principle in the scientific method is because we're concerned with making predictions, which means making working models of reality. A simpler, more inclusive model is more useful than a complex, less inclusive one. But it's a tool for of practicality, not objectivity. — Echarmion

I'm not sure that statement makes sense. Reality implies objectivity. And as both philosophy and science aim to predict reality, what works for science for that aim also works for philosophy. Note also that the Principle of Parsimony was first introduced not for science but for philosophy; and that science is a branch of philosophy (ie the search for truth), specializing in what is empirically verifiable.

Hume would simply say more people [...] are mistaken. — Wolfman

Why is this claim the most reasonable one? Appealing to the Principle of Parsimony, you (or Hume) have the onus of proof to defend it.

So...your point is? — Frank Apisa

That I think you are applying the PUP when you say you are more inclined to pick scenario (1) over (2). We are in agreement that reasonableness does not give certainty, but it is powerful enough to tip the scales.

Now...the answer I would much prefer. Neither! I do not do "believing"...by which I mean I NEVER EVER say that I "believe" anything. — Frank Apisa

This is an aside, but I want to say that your demand for certainty, all or nothing, is unreasonable for this world. Sure, this horse experiment is not consequential, but a lot of things are. We are not certain that Climate Change is real, but being agnostic is not a choice in this case. Either we fight it or we don't. And a 97% agreement among experts (let's assume that part is true) is sufficient to pick a side.

I know that people lie — unenlightened

The fact that is it possible for people to lie does not count against the PUP. It is like saying that the scientific method is flawed because scientists who apply it can always lie about the results.

I will trust my eyes [...]
I know that [...] people see what they want to see — unenlightened

Don't these two sentences contradict? Unless you say you are above the second claim; and indeed, that does sound arrogant :joke: .

people conform. — unenlightened

This is true, and we must take it seriously. Fortunately, it can be controlled by doing things like a double blind test, etc.

Now...the answer I would much prefer. Neither! I do not do "believing"...by which I mean I NEVER EVER say that I "believe" anything.
— Frank Apisa

This is an aside, but I want to say that your demand for certainty, all or nothing, is unreasonable for this world. Sure, this horse experiment is not consequential, but a lot of things are. We are not certain that Climate Change is real, but being agnostic is not a choice in this case. Either we fight it or we don't. And a 97% agreement among experts (let's assume that part is true) is sufficient to pick a side. — Samuel Lacrampe

You made an assumption on what I meant that was incorrect.

I am not looking for certainty in all things...even in questions about whether at least one god exists or not.

But when I make a guess about something (X)...I say, "I guess X. NOT "I believe X."

When I make a supposition about something (X)...I say, "I suppose X" NOT "I believe X."

If I estimate something (X)...I say, "I estimate X" NOT "I believe X."

If I have an opinion about something (X)...I say, "It is my opinion that X" NOT "I believe X."

I make guesses, I make suppositions, I estimate things, I have opinions just like everyone else...

...I just do not disguise my guesses, suppositions, estimates, or opinions by using "I believe..."

That is what I meant when I wrote, "I do not do "believing"...by which I mean I NEVER EVER say that I "believe" anything."

I hope that was clear.

As for the "climate change" example...I certainly see lots of reason (mostly from what the vast majority of climate scientists say)...that the danger "climate change" presents requires each of us to do as much as possible to get our elected officials to fight it with the same vigor they would use to fight an invasion from a foreign enemy.

That is not something I would say "I believe we should do it"...it is my opinion that we should do it.

Hello.
If I understand your post correctly, you say the PUP fails against radical skepticism, because the explanation of collective hallucination already presumes some things about reality, such as the reality of other subjects, where as the evil demon theory is more radical and makes no presumption about reality (except for the existence of said demon).

This is true. But although outside of the PUP, the evil demon theory also fails the Principle of Parsimony (which falls under rationalism and not under perceptions) which the PUP is also based on, because positing the existence of an evil demon is more complex than not.

Why is this claim the most reasonable one? Appealing to the Principle of Parsimony, you (or Hume) have the onus of proof to defend it. — Samuel Lacrampe

You presented your OP as if it were meant to circumvent Hume’s attack on perception, but it doesn’t. This is because on Hume’s view, there is a problem with how perception operates in the first place. This problem makes it impossible to render an accurate depiction of any external reality, if such a thing should exist.

Hume’s defense is on record. He’s devoted several books to explicating it. The onus is on you to explain why is it insufficient. And you don’t do this by appealing to the very system he says is flawed, and then adding a number element to it. That’s like Mill appealing to the supreme principle of utility in order to argue with Kant about how we ought to measure morality. Kant proceeds from a different normative framework, so it would be curious to invoke a rule that he doesn’t accept in the first place.

No because it is abnormal (using common sense alone, the normal is to not hallucinate), and so we would need to further explain the cause of that abnormality. In contrast, we don't need to further explain the existence of an oasis, as it is not abnormal. — Samuel Lacrampe

"common sense" won't fly in a serious discussion. You have to actually give reasons why it's "not normal" to hallucinate. Perhaps we are all hallucinating all the time?

Might as well believe that the whole world is an illusion, on the mere grounds that it is logically possible. But logically possible does not entail reasonable. For this, we appeal to further principles of reasonableness like Parsimony. — Samuel Lacrampe

How is parsimony going to help if everything is an illusion?

All I will say for now is that it is a perfectly accepted scientific principle, and that the alternative (that more complex is more reasonable) leads to a reductio ad absurdum: Can't prove there is no teapot in space? Then we'll believe there is. — Samuel Lacrampe

The application of the principle is far from clear even in the context of empirical science. There is plenty of discussion around just how to measure simplicity. In an epistemological discussion, it's not clear whether the principle applies at all. The Russel's Teapot example can be solved in other ways. For example, one might say that statements of existence or nonexistence about an object which is defined as unobservable are equally meaningless.

I'm not sure that statement makes sense. Reality implies objectivity. — Samuel Lacrampe

I think that this is the conclusion you wish to argue for in your argument, so you cannot use it as a premise. The problem Hume brings up is exactly that there seems to be nothing connecting reality (the things we experience) and objectivity.

And as both philosophy and science aim to predict reality, what works for science for that aim also works for philosophy. — Samuel Lacrampe

That would make the scientific method a fully general method to solve all philosophical problems, and that is clearly nonsense. Philosophy isn't necessarily concerned with predictions. Epistemology, for example, is concerned what we can know, not what we will know.

Note also that the Principle of Parsimony was first introduced not for science but for philosophy; and that science is a branch of philosophy (ie the search for truth), specializing in what is empirically verifiable. — Samuel Lacrampe

While this is true, William of Ockham, whose name has become attached to it, used it two differentiate between hypothses about phenomena, so a domain that we know attribute to empirical science. But regardless of it's origin, the principle must stand for itself.

it can be controlled by doing things like a double blind test, etc. — Samuel Lacrampe

I think you should call that the principle of universal imperception.

the scientific method is flawed because scientists who apply it can always lie about the results. — Samuel Lacrampe

You have a flawed conception of the scientific method. It does not rely on what scientists say but on what they can demonstrate. Thus a scientist may lie about what they did and what happened, but they will be found out when other people do the same thing and something different happens. and this is because scientists believe their own experience over what people say. And this was the revolution in thinking, that the old stories and claims were to be tested, and not believed just because everyone believed them before. "Show me, or it didn't happen" is the essence of science. "Everyone says it so it must be so" is the essence of dogma.

on Hume’s view, there is a problem with how perception operates in the first place. — Wolfman

What problem would that be, that is not covered by the PUP?

And you don’t do this by appealing to the very system he says is flawed — Wolfman

The Principle of Parsimony is flawed? Why is that?

Something that might help in general: The first line of the OP on Hume merely served as an introduction to present the PUP. I am not really looking to refute a claim by Hume, but to determine if the PUP is valid.

This is definitely a tangent, but... let's do it.
I think I have a clear enough understanding of the distinction between belief and guess, supposition, and estimate. But what is the difference between belief and opinion? Genuinely asking.

The Principle of Universal Perception (PUP) states that if a large majority of subjects perceive the same object, then it is reasonable to conclude that the object perceived is objectively real. — Samuel Lacrampe

This is risible.

"common sense" won't fly in a serious discussion. — Echarmion

I cannot agree with you there. Have you heard of the "absurd"? Reductio Ad Absurdum? All valid philosophical terms which criteria of judgement is common sense or common life experience.

You have to actually give reasons why it's "not normal" to hallucinate. — Echarmion

No sir. The onus of proof is on he who disrupts the status quo, and the status quo is that it is not normal to hallucinate.

For example, one might say that statements of existence or nonexistence about an object which is defined as unobservable are equally meaningless. — Echarmion

How is a teapot unobservable?

The problem Hume brings up is exactly that there seems to be nothing connecting reality (the things we experience) and objectivity. — Echarmion

Are you confusing the terms objectivity and subjectivity perhaps? Objectivity is defined as "external reality". Source

Philosophy isn't necessarily concerned with predictions. Epistemology, for example, is concerned what we can know, not what we will know. — Echarmion

True. I should have said that both science and philosophy aim for truth, which is conformance to reality.

But regardless of it's origin, the principle must stand for itself. — Echarmion

As previously mentioned, it is defended by the fact that the alternative method (that more complex explanations are more reasonable until proven false) leads to a reductio ad absurdum. Can't prove that invisible unicorns don't exist? Then they exist. And please don't ask me to defend the reductio ad absurdum principle, because we will then have a case of infinite regress.

I think you are inconsistent. If you claim that all subjects for the PUP can lie, then all scientists can also lie. How do you know the Earth is round? Did you conduct the demonstrations yourself, or do you rely on the claims of scientists?

Regardless, this is a misunderstanding about the PUP. As described in the OP, it states that "if a large majority of subjects perceives the same object, then [...]". It says "perceives", and not "claims to perceive".

Hello.

This is risible. — Banno

Give it time. It will grow on you.

What problem would that be, that is not covered by the PUP? — Samuel Lacrampe

I thought you knew since you invoked Hume’s name at the start of the OP. In any case, on Hume’s account we can only perceive perceptions (i.e. impressions and ideas). Perceptions are momentary and fleeting; hence we cannot perceive anything that is not momentary and fleeting. Your “solution” misses the mark because it presupposes or takes for granted that which Hume is denying in the first place (i.e. the ability to perceive anything other than perceptions). Before moving on you would need to show where Hume goes wrong. An appeal to “reasonableness,” or the “common” way we think about things, is not an adequate response because Hume is making a substantive philosophical point in highlighting the insufficiency of perception. This is why you are guilty of shifting the burden.

Something that might help in general: The first line of the OP on Hume merely served as an introduction to present the PUP. I am not really looking to refute a claim by Hume, but to determine if the PUP is valid. — Samuel Lacrampe

I’m not sure why Hume’s name was listed in the “problem,” since everything you say consequently has nothing to do with any of Hume’s criticisms. As noted earlier, in the context of the ECHU, what Hume describes as “metaphysics” doesn’t align with our contemporary understanding of the term.

...like a rainbow?

I cannot agree with you there. Have you heard of the "absurd"? Reductio Ad Absurdum? All valid philosophical terms which criteria of judgement is common sense or common life experience. — Samuel Lacrampe

The problem with that is that both people need to agree that the conclusion is absurd. Otherwise, why bother with this thread? You could as well have said "Hume says this, but clearly it is absurd, therefore he is wrong".

No sir. The onus of proof is on he who disrupts the status quo, and the status quo is that it is not normal to hallucinate. — Samuel Lacrampe

Oh that's clever. So you get to set the status quo and then get to ask everyone for proof?

How is a teapot unobservable? — Samuel Lacrampe

Let me quote the original argument: "If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.

Are you confusing the terms objectivity and subjectivity perhaps? Objectivity is defined as "external reality". — Samuel Lacrampe

Dictionary definitions are not arguments. That's how the term is generally used. Hume essentially questioned whether that use was actually correct.

True. I should have said that both science and philosophy aim for truth, which is conformance to reality. — Samuel Lacrampe

That sounds good.

As previously mentioned, it is defended by the fact that the alternative method (that more complex explanations are more reasonable until proven false) leads to a reductio ad absurdum. Can't prove that invisible unicorns don't exist? Then they exist. — Samuel Lacrampe

I don't think that those are the two only options. When discussing metaphysics a "true agnostic" position exists, i.e. there are simply things we can't make reasoned statements about one way or another.

Did you conduct the demonstrations yourself, — Samuel Lacrampe

YES. There's nothing like doing some experiments and making some observations for oneself, for giving confidence in science. I haven't done every experiment ever reported, life's too short, but I've done enough of the crucial ones to have confidence in the generality of physics and chemistry. This is how science is taught, and how it is done, no experiment is considered definitive until it can be repeated consistently.

Regardless, this is a misunderstanding about the PUP. As described in the OP, it states that "if a large majority of subjects perceives the same object, then [...]". It says "perceives", and not "claims to perceive". — Samuel Lacrampe

It comes to the same thing. Subjects can only know they perceive the same thing by communicating. But look, you are wrong. you have been shown to be wrong. And I'm going to leave it there. Do some science and stop pontificating about it until you have done some. You started with a misunderstanding of the difference between illusion and hallucination, and it has lead to what is essentially an anti-scientific dogmatic position with a slightly postmodernist spin. Nonsense.

Here's one you can do yourself on your next holiday. get yourself a good walking stick and the day before your holiday set to stand on level ground and measure the length of the shadow at noon, which is to say when the shadow is shortest. Jump on a train and head a few hundred miles North or South and repeat the measurement the next day. Also measure the stick and estimate the distance you have travelled North or South. Calculate the size of the Earth from these results just as the Greeks did thousands of years ago.

Hello.
If I understand your post correctly, you say the PUP fails against radical skepticism, because the explanation of collective hallucination already presumes some things about reality, such as the reality of other subjects, where as the evil demon theory is more radical and makes no presumption about reality (except for the existence of said demon).

This is true. But although outside of the PUP, the evil demon theory also fails the Principle of Parsimony (which falls under rationalism and not under perceptions) which the PUP is also based on, because positing the existence of an evil demon is more complex than not. — Samuel Lacrampe

Let me get this straight. You seem to be saying that what you call collective hallucinations are documented facts and that they contradict the Principle of Universal Perception because the latter relies on a large number of observations (many people perceiving what is in question) and that that could easily be an instance of collective hallucination which, in effect, invalidates the PUP.

Well, what needs to be mentioned here is that all knowledge of reality must give due weightage to the skeptic who claims that all that we perceive could be an illusion. Knowledge of anything, reality included, begins only after acknowleging the skeptic. In other words knowledge of reality will look like this: we know such and such about reality but it could be an illusion.

What does this mean for your idea of collective hallucination? As I see it, the skeptic's all could be an illusion is the worst-case scenario of your collective hallucination and we know we've already given due importance to the skeptic in re to knowledge of reality. Doesn't this mean your idea of collective hallucination is redundant? Your idea of collective hallucination, in extremis, is identical to the skeptic's all could be an illusion and since all knowledge of reality begins only after the skeptic's voice has been heard, your collective hallucination which is just all could be an illusion, worded differently, is already something all knowledge of reality factors in as a possibility to reckon with. Collective hallucination is superfluous in that respect.

Samuel Lacrampe
794
↪Frank Apisa
This is definitely a tangent, but... let's do it.
I think I have a clear enough understanding of the distinction between belief and guess, supposition, and estimate. But what is the difference between belief and opinion? Genuinely asking. — Samuel Lacrampe

You are still missing my point. I hope my answer to this question makes it clear.

There is absolutely NO DIFFERENCE between a "belief" and an "opinion"...EXCEPT for the use of the word "belief" rather than opinion. "Belief" HIDES the fact that it is an opinion...whether intentional or not.

Fact is, in most discussions of religion or philosophy...there is absolutely NO DIFFERENCE between belief and guess, supposition, or estimate either...EXCEPT for the use of the word "belief" rather than guess, supposition, or estimate. Using "belief" HIDES the fact that it is a guess, supposition, or estimate being offered...whether it is intentional or not.

Consider this: I "believe" there are no gods. That is a guess...a blind guess at that. But, if the person delivering it said, "I blindly guess there are no gods"...it becomes almost laughable.

Same thing in the other direction. I "believe" (in) God. That is also a blind guess. But, if the person delivering it said, "I blindly guess that God exists"...could you imagine that person (or anyone else) suggesting we should all "respect" other people's blind guesses.

Imagine this: I flipped a coin. If it comes lands "heads" I will guess there is a God; if it lands "tails" I will guess there are no gods. And I expect you to respect my guess.

It is the use of the words belief/believe that I am dealing with...not any difference that people pretend exist.

The problem is in the precept that all that can be known is what is perceived. There is a real subconscious world we have as yet only had the faintest inkling of.

And what is the physical, anyway? Science is at a loss. We simply have misplaced faith that these men we worship will figure it all out. But the truth is I could claim everything is a metaphysical phantasm. Only the dullness of familiarity convinces us otherwise.

I could claim everything is a metaphysical phantasm. — neonspectraltoast

You could, but no one would care.

An analogy for truth, I have adopted, is the sense side of the state of affairs, whereas reality is the universe side.

Can we test if it is real? Can we falisfy solipsism?

... that you fly to the furthest star, you can. Is it this sort of logic? Probably not. It's probably simple.

You know the universe shape well, then you know the fact consciousness can be in P body, meaning that P consciousnss is a equal thought as consciousness.

It also takes great logic behind what's going on to supply your solipsism and it may be a great danger.

They'd care if I had enough money. And whether they cared or not wouldn't determine the truth of the statement. There are literally a million truths no one cares about.

we can only perceive perceptions — Wolfman

So you claim that when we perceive an object, it is never the object in reality. And why would that be? If it looks, sounds, and feels like a duck, is it not reasonable to believe it is in fact a duck, until given a reason to believe otherwise?

Precisely. A rainbow of wisdom.