God is absolutely indispensable to Berkeley's idealism.

You seem intent on making me do your work for you. My comment was an attempt to persuade you to go read Berkeley himself and examine his arguments, as I myself don't have the time, or really the interest, to do so at present. I just don't recall that God is "invoked" or assumed to exist, as you suggest. — Thorongil

This is a discussion forum. You can't expect others to go read material in the middle of a discussion.

Well, Schopenhauer regarded Berkeley's idealism as more or less capable of standing on its own, while dispensing with God.

So, you're appealing to authority now? (Not that I think Schopenhauer is much of an authority!) In any case, what does "more or less" mean in this context?

You can't expect others to go read material in the middle of a discussion. — Marchesk

Yes, but I in turn can expect that philosophers one hasn't read won't be rejected.

Well, Schopenhauer regarded Berkeley's idealism as more or less capable of standing on its own, while dispensing with God. — Thorongil

No God, no tree in the quad!

You can dispense with God, but subjective idealism loses the world when we're not looking, which Berkeley was concerned about.

If you don't think of him as much of an authority, then my appeal to him will be meaningless to you, that is true. I don't know why you would think that, though.

Yes, but I in turn can expect that philosophers one hasn't read won't be rejected. — Thorongil

I'm familiar with Berkeley's main arguments and what people have said about his using God, which is similar to what Descartes did. I guess you could claim that Descartes had some other reason than needing to be saved from his skeptical exercise.

Or you could just give me a brief summary of Berkeley's arguments for God.

I think Schopenhauer was a second-rate thinker because his philosophy is basically a rehash of Kant, coupled with a poor set of arguments that we know what the noumemon is; that it must be undifferentiated; that it must be Will, must be unknowing, and so on. I think he read the Upanishads too much, and read too much into them.

Or you could just give me a brief summary of Berkeley's arguments for God. — Marchesk

I just got done telling you I don't have one to give and don't have the time to go and do that properly. I mean, you could try Google and find something like this: http://faculty.bsc.edu/bmyers/BerkeleyGod.htm . But I'm not in a position to assess those presentations' accuracy. The second argument in the link might be what you and John have in mind, but not the first, at least.

Alright, thanks. The second argument I find interesting:

1) All ideas must be perceived.

2) Sensible objects are collections of ideas.

3) Objects continue to exist even when they are not perceived by any finite minds. 4) Therefore, there is a nonfinite spirit or mind which perceives objects. — Bishop Berkeley

Materialists would agree with the bolded part. It's interesting because subjective idealists tend to disagree that objects continue to exist outside human/animal perception.

Now why would Berkeley be convinced that objects continue to exist, given that he was a subjective idealist?

Those seem like poor reasons to me. What philosopher doesn't rehash the ideas of his predecessors? What philosopher is without poor arguments? If you've discovered the fount of wisdom himself somewhere in the history of philosophy, I would ask that you point him out to me and tell me why others have not seen his infallibility.

Materialists would agree with the bolded part. — Marchesk

They would, but Berkeley naturally wouldn't hold that they exist as matter. There is a reason why Berkeley called his position "immaterialism" not "idealism," though I think he's clearly an idealist of some kind.

In the first argument, a is interesting:

a) Our ideas of sense must have a cause — Bishop Berkeley

Because Berkeley ignores Hume's point, but many idealist love to use Hume's skepticism to undermine materialist arguments for causation.

Materialists would agree with this premise as well!

1) All ideas must be perceived. — Bishop Berkeley

Question for anyone: how does Berkeley distinguish between other experiences and perception? Is my dream tree not an idea? Must ideas be public/intersubjective?

Anyway, from reading those two arguments, I think Berkeley would side with materialists over atheist subjective idealists if he was forced to choose between the two.

He seems to fundamentally agree that objects persist and have causes, both of which subjective idealists tend to deny.

It's more that some thinkers have greater originality, which means being less derivative, than others. But it's always going to come down to affinities. For example I find Hegel a far more interesting and penetrating thinker than Schopenhauer. He obviously drew upon Kant also, but redirected the sage of Konigsberg's philosophy onto much richer and more fruitful paths than Schopenhauer did, in my opinion.

I would contend that Schopenhauer is highly original. Whether you are convinced by it or not, the ontological relationship between intellect and will he proposes is unique in the history of philosophy, as are a number of other doctrines and positions he advances.

In what way do you think " the ontological relationship between intellect and will he proposes is unique in the history of philosophy", and what are "the other doctrines and positions he advances" you refer to?

Name me another major philosopher who advances the ontological primacy of will over intellect. Most, if not all, philosophers throughout history have regarded the will as an operation or function of the intellect. Other unique doctrines and aspects would be his aesthetics, especially his theory of music, his non-materialist atheism, his arguments in favor of strict asceticism, his incorporation of Eastern religion and philosophy, his soteriology, etc.

Name me another major philosopher who advances the ontological primacy of will over intellect. — Thorongil

Hume said the intellect is slave to the passions; so the idea is hardly original. Schopenhaurer's aesthetics draws heavily on Kant. About the most interesting idea he had, in my view, is that (great) art reflects the forms, rather than merely imitating the sensory world (as Plato apparently thought). It's true he was greatly influenced by Eastern ideas, and his soteriology is not substantially different than Buddhist or Brahmanic soteriologies.

Anyway I'm not really interested in arguing over the respective greatness of philosophers; I acknowledge that it is a matter of taste, just as it is with artworks; so I was only expressing my own opinion of Schopenhauer's place in and importance to, the pantheon.

Hume said the intellect is slave to the passions — Janus

Oh come on, they were hardly positing the same thing.

Anyway I'm not really interested in arguing over the respective greatness of philosophers; I acknowledge that it is a matter of taste, just as it is with artworks; so I was only expressing my own opinion of Schopenhauer's place in and importance to, the pantheon. — Janus

Alright, as was I.

Oh come on, they were hardly positing the same thing. — Thorongil

Why not? Just because Schopenhauer reified the passions as Will; whereas Hume did not? Schopenhauer also drew upon Spinoza's idea of conatus, I believe. And the idea of the striving of all against all, and nature as red in tooth and claw can also be found in Hobbes.

Are you saying that there is no understanding of 'perception' which doesn't entail that the thing perceived exists unperceived? — PossibleAaran

No, you can have specialized senses of "perception" but e.g. something like Schrodinger's Cat is a thought experiment based on possibilities opened up by scientific understanding (and anyway, it's not settled science yet, there are interpretations of the science that don't have any weird implications like the SC thought experiment does).

Moreover, if it were so, then there would never be a need for me to check whether something I saw earlier is still there now. It would make no sense, for example, to see a sand castle at T1 and then wonder later about whether it exists when you are in the coffee shop, or whether it has blown away in the wind. I can just say "well, it follows from the meaning of the word 'perceived' that the sand castle I perceived earlier must still exist". — PossibleAaran

Those kinds of changes aren't related to perception but to the existence of objects already considered as part of the causal backstory to perception (e.g. things decay and get washed away, etc., but they don't pop out of existence when unperceived).

It is plain as day to me that my own ordinary understanding of the word 'perceived' entails only that the thing perceived must exist at the moment I am perceiving it. It says nothing about any other moment. — PossibleAaran

No, it's the perception that exists only while perceived. But the perception is not the thing perceived, the thing perceived is the thing perceived, and things perceived are such things as exist also while unperceived (and that can be checked by the numerous ordinary means).

Another point to make is that your view about the ordinary meaning of "perceived" is an empirical hypothesis. It says that ordinary members of the population use the word "perceived" such that perceiving X entails that X exists unperceived. Recent experimental philosophy has made it clear that ordinary language users don't always agree with philosophers about what a word means and made even more clear that the best way to figure out what ordinary words mean isn't just to take a guess from the armchair, or even to talk with other philosophers about what it is 'intuitive to say'. The best way to find out is to actually go out and ask questions to ordinary folk which indicate the meanings of their words (you could see, for example, any study by Stich, Machery or Weinberg). Hence, my suggestion is that we cannot really tell whether the ordinary meaning of 'perceived' is what you say it is, or even that there is a ordinary meaning. — PossibleAaran

I'm not sure what fallacy this is precisely, but it reminds me of the Continuum Fallacy, so I'll call it that :) No language (with the possible exceptions of French and made-up languages like Dothraki) has that kind of clear delineation, living languages are a resultant or precipitate, the result of human action but not of human design, and there are always individual and local variations, misunderstandings, outliers, edge cases, idiosyncratic usages (just as there are idiosyncratic pronunciations), but that doesn't mean there aren't relatively stable meanings everyone understands. If it weren't so it would be impossible to understand each other. As it is, it's only a problem now and then, when we might have to clarify some particular point, or define terms in a complicated discussion.

Even if the ordinary meaning of 'perceived' were as odd as you suppose it to be, I don't think that is of any importance at all. I would simply reformulate in new terms. I held previously that humans have two reliable sources of belief about the present and future (memory has to be included for the past, but this can be omitted for now): perception and inference from sense perception. If perceiving X entails that X exists unperceived then I shall reformulate my view. Instead, I say that humans have two reliable sources of belief, Schmerception and inference from schmerception. Schmerception is what is happening when various properties and/or objects are brought before your conscious awareness. We could say that Schmerception 'gives' items to you in awareness. Schmerception doesn't entail that what is schmercieved exists when unschmercieved, since being consciously aware of some object or property at T does not entail that the object exists at any time T1, when it is not something you are consciously aware of. Perception is not, although I thought it was, a reliable way to learn about the world, since "perception" turns out to mean this odd and mysterious thing where perceiving something at one time entails that it must exist at other times. Perception, so understood, has nothing to do with my conscious awareness of the world, since that conscious awareness doesn't entail that the things I am aware of exist unperceived. I am not really sure that perception is, if that's what it means. Perhaps perception is just Schmerception of things which also exist when unschmercieved. Perhaps, but then the fundamental method of finding out about the world is schmerception, and perception is a thing I can do only if there are things which exist unschmercieved. — PossibleAaran

Again, this falls under the thing I was saying of painting yourself into a corner of your own making. Schmerception is a viable concept (it's actually the same as non-dual or "mystical" understanding or perhaps the radical empiricist view, that I mentioned in an earlier post), but Schmerception can't help itself to talk of "objects" and "properties" in the same way as perception would. For example: how do you know you can legitimately draw inferences from Schmerception? The game of drawing inferences from perception depends on the causal backstory of a world that exists unperceived, but if you've taken away that presupposition to give you Schmerception, then you've also left open to question the idea that you can "reliably" draw infererences from it. So paradoxically, your effort to get better reliability has led to greater doubt!

I understand the attempt which you are trying to make. You are trying the ever popular method of building our ordinary worldview into the meaning of our ordinary words. Doing this is supposed to make us feel better about those views. It is supposed to somehow prevent sceptical challenges to those views, since the sceptic will be unable to meaningfully state any challenge to those views using ordinary language. — PossibleAaran

No, it's not that, it's not that you can't challenge the view, it's that you're not giving any good reason to doubt the view. You're not actually presenting a sceptical challenge. The idea that things might pop out of existence when unperceived is just an imaginary notion, there's no reason whatsoever to take it seriously, and all the reasons we do have mitigate against it.

Thus, I can't meaningfully ask whether there is any reliable way to determine that things exist unperceived while using the ordinary notion of 'perceived'. The problem is, if I am really sceptical about ordinary views because those views don't meet a standard which I deem important (reliability), I won't be impressed by the thought that those views are built into my language. — PossibleAaran

What are you talking about? Perception is the very standard of reliability, there is no other, better standard; you certainly don't know whether Schmerception would be any better!

If you're not sure whether something exists unperceived by you, then (with increasing degrees of rigour) ask a friend, or do the camera test, or a video test, or if you're really doubtful (perhaps you suspect someone's jockeyed with the video feed) you can do a more sophisticated sort of scientific test. That's precisely the sort of area where "reliable" lives.

So what if they are built into my language? Other cultures use other languages and their language might not be such as to have my ordinary views build into it. If so, how can we reliably establish which culture is right? The appeal to language obviously won't do. This was made very clear in a paper by Stich entitled Reflective Equilibrium, Analytic Epistemology and The Problem of Cognitive Diversity. — PossibleAaran

All languages are guaranteed to have some basic ideas built in, because human beings have evolved from creatures that had to embody an answer to the basic features of the world, and that just gets carried over to language. Language isn't all that relative - it's the same as the argument above, yes there are differences and idiosyncracies, and different ways different languages handle things, but any language that didn't have the basic causal backstory would lead to the humans using it not surviving to reproduce.

What you are doing is asking for a justification for your belief, and following each suggestion with "But I am still not convinced".

Your failure to be convinced is not our problem. — Banno

I didn't ask for a justification, if that means some proof from premises which I accept. I asked for someone to tell me a story such that, if true, the belief that things exist unperceived was produced by a reliable method or process - a method or process which makes it objectively likely that things exist unperceived. Any story will do, so long as you can convince yourself that it is actually true. You can postulate a special magical faculty deep in your brain that allows you insight into the unobservable, if you can convince yourself that you have such a faculty.

I didn't say I'm not convinced that things exist unperceived either. As it happens I am convinced of it.

So, what difference does that qualification make? — Janus

Induction, deduction and inference to the best explanation vastly increase our knowledge beyond mere perception.

I'm asking whether you regard seeing something as perceiving it, but do not regard hearing something as perceiving it. That seems to be implied by your statement (at the top of this post: ↪PossibleAaran) that we do not perceive a motor that we hear, but that we do perceive a table that we see.

If that is your position, do you think it stands up to scrutiny? I wonder what a blind person would think about the suggestion that they don't perceive anything.

If that is not your position then which side would you alter? Would you agree that we do perceive things that we hear, or that we don't perceive things that we see. I can see no other way out of the difficulty, than one of those two options, although I am open to suggestions. — andrewk

I see your point. Previously I maintained that hearing the motor was not sufficient for reliably detecting its existence. I should not have maintained that. Still, that I hear the motor only establishes that it exists when heard. The paper in my drawer is not heard.

The paper in my hand could very well be a dream paper, after all, which doesn't exist. But it can seem very real. The possibility of error -- the probability -- is close enough to the same (I'm not sure how we could even come up with an actual number here, but just by judgment on my part) that there isn't a difference. — Moliere

What is the difference between a merely dreamt tree and a real tree? I think the answer is two-fold. First, a real tree is a tree which can be perceived by other people, and second, a real tree is a tree which exists even when I am not aware of it. The tree that I see when dreaming cannot be seen by other people and exists only when I am seeing it. When I wake up, the dream tree no longer exists. Now your other question:

what kind of certainty would actually make the existence of the perceived any more certain that the existence of objects after they have been perceived? — Moliere

While an object is being perceived I am directly aware of it. When I am directly aware of P I am - to say the very least - in a good position to tell that P exists. When I am no longer perceiving P, how can I reliably tell that P is still there?

Not sure how you can accept chemistry as scientifically valid without conceding the existence of the atomic world which makes the periodic table what it is. Same with the germ theory of disease, cell biology or neuroscience.

Sure, we have equipment that can make those things perceivable to us, but most of the time atoms, microbes and cells are unperceived. The molecules science says you are made might never have been perceived by anyone. — Marchesk

Didn't we already go over this Marchesk? The existence of atoms can be inferred from things which can be perceived. This suffices to establish that atoms exist whenever we observe ordinary objects like trees, tables and the like. Do the atoms exist when we don't perceive the tree? If they did, the tree would also exist unperceived, since the atoms compose the tree. But my question all along has been how this can be known, even assuming all of our usual methods of confirming things.

Or maybe, just maybe, classical physics works so well precisely because its assumptions about macroscopic objects are accurate! — Aaron R

Perhaps. That sounds like quite a strong argument to me. One issue which I am thinking of is this. Classical Physics can be interpreted in an Idealist fashion, so as not to posit anything which exists unperceived. Doing so would not conflict with any of the available evidence. Presumably then, the Idealist interpretation of classical physics would work just as well as the Realist one would. It is just a contingent truth that we happen to use the Realist interpretation. But then, couldn't this argument of yours be made in favour of Idealism? The fact that the Idealist interpretation works so well is best explained by the hypothesis that it is correct - that things do not exist unperceived. That sounds like just as strong an argument to me. Unless, in some sense, the Realist interpretation works better than the Idealist one. I can't see what sense of 'works better' would be involved though.

You seem to be haunted by the the prospect that you might be wrong. Get used to it. Such is life! — Aaron R

Not at all.

I think our discussion has spun off in too many different directions to be useful. I'll try to simplify, if you will follow me in this. Imagine a dialogue between you and I:

PA: What reliable method is there for determining that things exist unperceived?

GG: If you want to know whether a piece of paper in the drawer exists when you aren't perceiving it, put a camera in the drawer and take a picture.

PA: A camera is an extension of perception. Your camera procedure shows that the paper exists when photographed. Does the paper exist when unperceived and un-photographed? How can that be reliably determined?

I am not sure what you would say at this juncture. Here are some of the things you have said (Or I have interpreted you as saying). I don't know which, if any, fits at this point:

GG1: It is part of the meaning of "perceived" that things perceived always exist unperceived.

GG2: Things perceived do exist when unperceived (and that can be checked by the camera test).

GG3: Perception is the very standard of reliability. Perception and other ordinary procedures like the camera test are "where reliability lives".

GG4: The idea that things might not exist when unperceived is just an imaginary notion. There is no reason to think that it is true, and all the reasons we do have (the camera test) militate against it.

Which of these would you insert in our dialogue, if any? Would you insert something different, or some combination of them?

On your other point about language. I agree that language in ordinary use does not usually have very precise meanings. I also agree that there are relatively stable meanings of words, at least, if we confine ourselves to specific groups of people or cultures. Remember, it is you that insists on the empirical hypothesis that the ordinary meaning of "perceive" entails that things perceived also exist unperceived. It is you that thinks ordinary language is very clear on at least that one point. I am simply pointing out that this is an empirical hypothesis which you have given no evidence for. You have simply assumed that this is part of the ordinary meaning of "perceived" as most people use it, perhaps because that is how you use the word.

To all I am thinking at this point that it is not as clear as I had hoped what the question is that I am asking. I am thinking that perhaps putting the point in terms of "reliability" is not as helpful as I thought it would be. I will try to think of another way to frame the issue. I am open to suggestions.[/b]

Best,
PA

The paper in my drawer is not heard. — PossibleAaran

It is though, as I explained in this post (which was on page 2 of 9, so it's understandable that it has been forgotten).

The resonance of your footsteps on the floor, and even the micro-audible vibration of the desk as air moves over it, will differ according to how many pieces of paper are in the desk drawer.

In order to talk about things that may have no effect at all on your sensory organs, you need to at the minimum change the focus to objects outside your past light cone, which means objects in distant outer space. There are difficulties there as well, but they are different difficulties.

What is the difference between a merely dreamt tree and a real tree? I think the answer is two-fold. First, a real tree is a tree which can be perceived by other people, and second, a real tree is a tree which exists even when I am not aware of it. The tree that I see when dreaming cannot be seen by other people and exists only when I am seeing it. When I wake up, the dream tree no longer exists. — PossibleAaran

There are certainly differences, but I think that misses the point of the dream scenario. The point of the dream scenario, here, is to show that we can believe that what we percieve is real when, in fact, it is not.

So the dream-tree does not exist, even when I am seeing it. It is a dream. It doesn't pop in and out of existence. It never existed ever. Yet, upon my perception of it, I certainly believed it to be real.

So our perception of things is not infallible, at least, when it comes to determining if something exists or does not exist.

If you insist on the dream being real, then consider hallucinations, mirages, delusions, and so forth. Our perceptions are surely not infallible when it comes to determining if something is real or not.

This isn't to claim the part of a skeptic, but to point out that what you already accept as reliable is basically just as reliable as having seen something.

While an object is being perceived I am directly aware of it. When I am directly aware of P I am - to say the very least - in a good position to tell that P exists. When I am no longer perceiving P, how can I reliably tell that P is still there?

I'd say that if you have seen something you are aware of it. When I park a car in a garage and close the door I am aware that my car is in the garage. Something may have happened in the meantime. And I may have been dreaming. But because I have seen where I put my car I am in a good position to tell that it exists because I am aware of its existence.

Perhaps. That sounds like quite a strong argument to me. One issue which I am thinking of is this. Classical Physics can be interpreted in an Idealist fashion, so as not to posit anything which exists unperceived. Doing so would not conflict with any of the available evidence. Presumably then, the Idealist interpretation of classical physics would work just as well as the Realist one would. It is just a contingent truth that we happen to use the Realist interpretation. But then, couldn't this argument of yours be made in favour of Idealism? The fact that the Idealist interpretation works so well is best explained by the hypothesis that it is correct - that things do not exist unperceived. — PossibleAaran

The difference is that the idealist accepts beliefs that prima facie contradict the assumptions made in the model itself. The realist will argue that the simplest meta-level hypothesis is that the model works because the assumptions are really true. The idealist has a number of interesting responses that they can give to this. As we've discussed, I'm not suggesting that the realist can wield the scientific method to disprove idealism because strictly speaking the scientific method does not "prove" or "disprove" anything at all. If you are looking for a reliable method that can be used to draw conclusions that only the realist can accept, then I believe you are indeed out of luck. The idealist can add meta-level hypotheses to any theory in order to make it consistent with idealism.

So, what difference does that qualification make? — Janus


Induction, deduction and inference to the best explanation vastly increase our knowledge beyond mere perception. — PossibleAaran

That's true, but all are founded on perception. I think the problem you are having in seeing this is that you are thinking of perception in its singular immediate sense, rather than its multiple, cumulative sense.

The resonance of your footsteps on the floor, and even the micro-audible vibration of the desk as air moves over it, will differ according to how many pieces of paper are in the desk drawer.

In order to talk about things that may have no effect at all on your sensory organs, you need to at the minimum change the focus to objects outside your past light cone, which means objects in distant outer space. There are difficulties there as well, but they are different difficulties. — andrewk

Ah yes, I remember you saying this before. I find that an interesting idea, but there are some issues. Stick with the paper example. Let's agree that the resonance of my footsteps on the floor will differ depending on whether or not there is a paper in the drawer. Well, then I could use specialized equipment to measure the resonance of my footsteps on the floor, and I could infer from observations about the resonance that there must be a paper in the drawer (this argument would be quite complicated I take it, but let's assume for now that it could be worked out cogently). Well that would certainly establish that the paper exists when I am observing those resonances, but clearly I am not always observing them. I am not observing them now, for example. My sensory faculties just aren't refined enough to detect them. Does the paper exist when I'm not observing the resonances? A further inference still seems to be needed.

So the dream-tree does not exist, even when I am seeing it. It is a dream. It doesn't pop in and out of existence. It never existed ever. Yet, upon my perception of it, I certainly believed it to be real.

So our perception of things is not infallible, at least, when it comes to determining if something exists or does not exist.

If you insist on the dream being real, then consider hallucinations, mirages, delusions, and so forth. Our perceptions are surely not infallible when it comes to determining if something is real or not. — Moliere

I am not sure about this, but it is interesting to think about.

Take the dream tree, does it exist? Well, if it doesn't exist then what is it that you are aware of when dreaming? Nothing? But it sure seems like you are aware of something doesn't it? Some qualities are there before your consciousness are they not? If I were to ask you about the dream tree, couldn't you tell me about it? You could tell me "it had a trunk 500 metres high and purple leaves", for example. If you told me that, you would be describing what you were aware of when you dreamt, and you couldn't do that if there were nothing you were aware of when you dreamt, could you? This is what leads me to insist that the dream tree does exist and that the only difference between it and a real tree is that a real tree can be perceived by others and exists unperceived also. In fact, I would go as far as to say that what I mean by "real tree" is " a tree that can be perceived by others and which exists even when no one is perceiving it".

Our perceptions aren't infallible. I can make mistakes in perception, as when I think that a tree is 'real' but it isn't. But what this mistake amounts to is that I thought the tree was such that it could be seen by others and existed even unperceived, and I was wrong on both counts. But, even when I was hallucinating, I couldn't be mistaken that I was seeing a tree - even if it turned out to be a mere hallucination tree. This is essentially Descartes' view that he cannot be mistaken that he seems to see a fire, even though an evil demon might trick him into thinking that there 'really is' a fire. I have just tried to explicate what I mean by 'real' and used this concept instead of Descartes' terminology, because I think his terminology encourages the veil of perception doctrine (I do not think that he actually espoused that doctrine, but his phrasing in an English translation makes it very tempting). Whether you mean the same thing by 'real' I am not sure. It would be interesting to find out what you do mean by 'real' if not my explication, and equally interesting to determine whether dream trees or ordinary trees are 'real' in your sense, and what bearing this would have on our present subject matter.

Thanks for the reply. It seems that you are of the view that I cannot really get what I am asking for. You might be right.

PA

My sensory faculties just aren't refined enough to detect them. Does the paper exist when I'm not observing the resonances? A further inference still seems to be needed.

This raises an interesting question about what we mean by 'detect', or 'perceive'. Specifically, do we want 'perceive' to mean the same thing as 'notice'?

My eardrums will be vibrating in a slightly different way from how they would if the paper were not there. And maybe even the electrical signals sent along nerves from my ear to my brain are slightly different. But I do not notice these differences. Would we then say that I do not perceive them, even though the difference in information is reaching my brain?

The famous psychology experiment about the gorilla on the basketball court provides a super example to focus on this question. The people's sensory organs detected the gorilla, and the signals about that reached the watchers' brains, but the watchers did not notice the gorilla. Would we then say that they did not 'detect' or 'perceive' the gorilla.

What if the gorilla and all the basketball players were robots (so that none of them can be conscious of the gorilla) and the only animals in the room were watchers, none of whom noticed the gorilla. Would we say the gorilla was 'unperceived' and if so would the question about whether the gorilla existed be essentially the same as for the paper in the drawer?