And what is the nature of this chain? — Wayfarer

There is an article Arguments against Direct Realism and how to counter them by Pierre Le Morvan, where he writes, when discussing the causal argument against Direct Realism:

"It’s wise for Direct Realists to concede that for humans, and for percipients physiologically
like us in the actual world, perception involves a long and complex causal series of events, and that perception is indeed dependent upon the condition of the eyes, of the optic nerve, and of the brain, upon the nature of the intervening medium, and so on."

"But perception involves a long and complex causal series of events. For instance, light quanta are reflected or emitted from an external object, the light quanta then travel through an intervening medium (e.g., air and/or water), they then hyperpolarize retinal cells by bleaching rhodopsin photopigment molecules, and then a very complex series of physiological processes takes place in the eye and in the brain eventuating in perception."

Light travelling from the something in the external world that we perceive as a green tree with three branches to the eye of the perceiver is part of this causal chain.

Part of the nature of this causal chain is that causal relations are generally understood to be asymmetric. This asymmetry is often assumed to coincide with a temporal asymmetry according to which effects do not precede their causes.

As Searle wrote in The Philosophy of Perception and the Bad Argument, perception has the mind-to-world direction of fit and the world-to-mind direction of causation.

Excellent response. I shall read and reflect on that.

Even if it was true that trees are concepts that exist only in the mind, they are at the same place in the causal chain as the rest of the perceiver, as already intimated, and so are not intermediaries between perceiver and perceived. The perceiver cannot put himself before himself on the causal chain.

"The bad argument" is the name Searle gives to what you produced as a throw-away, but which others have taken seriously — Banno

And why do you think many have taken it seriously.

Suppose just as many people take it seriously as take it as a "bad argument". Who do we believe? What's the ultimate consensus? And is the majority even relevant? Does collective stance (based on collective experience) hold more weight than minority stance?

. The perceiver cannot put himself before himself on the causal chain. — NOS4A2

Well they can. Self-fulfilling prophecies are an example of where a certain expectation of future outcome causes the resultant future outcome.

For example, if I say, oh I'm stupid, it's no use trying for that job application in a month, I'm not good enough to get offered the position. You then proceed not to prepare or research, and then ultimately because of this ill-prepared state and lack of charisma you do end up failing to get the job. You already knew you wouldn't. The events confirm your belief and the belief itself confirm the events.

You can argue that your belief about the future brought around that future. As an inevitability.

Which way does causality work here? Did the future absolutism behave in the same manner as a past defined absolute. Dictating the impossibility of it ever becoming a reality?

Another example, I say someone is trying to incarcerate me against my will because they don't believe I'm mentally well. A family member is concerned about the unfounded confession and all the anxiety and agitation that comes with it and brings you to a psychiatrist which agrees that you are in need of help. So they involuntarily commit you. Thus confirming your original statement as correct.

The prediction was for all intents and purposes accurate and so further aggravates your anxiety/agitation about what you knew would happen.

No one can say you're wrong. As it did happen. And then that begs the question if your fear was confirmed as valid/real ought that not invalidate the very reason for you to be considered deluded and in need of help?

Even if it was true that trees are concepts that exist only in the mind — NOS4A2

You wrote: "For the direct realist, the man directly perceives a tree............For the indirect realist, though, something within the man (the mind, the brain, a little man) directly perceives something else within the man (sense data, representation, idea).

If the man directly perceives a tree, and the tree is a concept that exists only in the mind, doesn't this mean that the man is an Indirect Realist ?

I would agree with that.

I also said “the boundaries between both X and Y are so unclear and amorphous that it could rather be the case that X is directly perceiving X.”

How can we perceive a concept that exists only in mind if our eyes point outward, not inward? If the tree is a concept that exists only in the mind, somewhere behind the eyes, that would place the tree at the tail-end of the causal chain.

"It’s wise for Direct Realists to concede that for humans, and for percipients physiologically
like us in the actual world, perception involves a long and complex causal series of events, and that perception is indeed dependent upon the condition of the eyes, of the optic nerve, and of the brain, upon the nature of the intervening medium, and so on."

"But perception involves a long and complex causal series of events. For instance, light quanta are reflected or emitted from an external object, the light quanta then travel through an intervening medium (e.g., air and/or water), they then hyperpolarize retinal cells by bleaching rhodopsin photopigment molecules, and then a very complex series of physiological processes takes place in the eye and in the brain eventuating in perception." — RussellA

Sure, for me to perceive the tree, I need light. For me to perceive the tree, I need to have my eyes open. And this is suppose to turn me into indirect realist because of the causal train of events.

So, if there is no light the tree does not have a color, when there is light the tree has color. But to be a direct realist, it has to have a color for me to directly perceive no matter if there is light or not? Yes, according the indirect realist, it is part of the casual process.

Based on their logic, the indirect realist does not have to introduce the mind, brain, nerves, sense data, etc to refute the direct realist. They got light on their side.

But I do not think the direct realist should be concerned about how we perceive, but how we learn and use the word “perceive”, how we make judgements about what we perceive, or how we gain knowledge from what we perceive.

I have attempted to show indirect realism: 1) Is incoherent based on this idea of "directly perceiving sense data" because it was shown to be a grammatical fiction. 2) cannot be determined to be truth, in principle, due to the nature of "sense data" being a private, inaccessible experience. 3) inadequately claims to universally applied to all human beings if based on hallucinations which most do not experience. 4) pragmatically does not differ from direct realism in terms of establishing knowledge claims.

Next, I like to show at least one example of human beings directly perceiving something which an indirect realist would wrongly claim to be an inference. This is to show at least it is plausible this idea of direct realism. Also, I like to show at least one example of an illusion which conflicts with this idea of human beings must have "sense data" to explain such phenomenon.

a. I draw a stick figure of a person from my imagination. I show this picture to a child and ask her "what to you see?" The child may reply, "I perceive a stick figure of a person." Can we not claim that the child directly perceives a picture of a stick figure? It seems incorrect to say this is an inference from my perception of sense data. I drew the figure, I know exactly what I intended to draw. The child reported exactly what I drew. It is difficult for the indirect realist to say, "Well, we cannot say what is behind this sense data of the picture of the stick figure" because the author of the creation is telling us what it is, (unlike "Mother Nature" who seems to hide her secrets according to the indirect realist).

b. The famous picture of the "duck-rabbit" is an illusion. If presented to someone, they could see the picture as a rabbit, or, another time, see the picture as a duck. However, could we not say the what we perceive is the same figure in both cases? If so, the positing of sense data has no explanatory power in this case to explain this illusion.

For the indirect realist, though, something within the man (the mind, the brain, a little man) directly perceives something else within the man (sense data, representation, idea). But the boundaries between both X and Y are so unclear and amorphous that it could rather be the case that X is directly perceiving X. — NOS4A2

I also said “the boundaries between both X and Y are so unclear and amorphous that it could rather be the case that X is directly perceiving X.” — NOS4A2

The perceiver and what is directly perceived by the perceiver must be one and the same

There is X, the mind, the brain, the little man and there is Y, sense data, representation, idea. X is the perceiver and Y is what is perceived.

As Searle said, pain cannot be removed from the experience of pain. Similarly, what is directly perceived cannot be removed from the perceiver.

As Brentano said about intentionality, mental states are an incomplete essence, in that they cannot exist unless they are completed by something other than themselves. The relation between the intentionality of the mind and the intentional object cannot be a causal relation.

For the mind to understand an object it is perceiving, the mind must have ideas about the object. The ability to have ideas must be part of the essence of the mind. The mind, distinguished by the ability to have ideas, is then able to perceive ideas.

But if the mind is X, and Y is ideas, and if the mind is distinguished by its ability to have ideas, then X must by Y.

How can we perceive a concept that exists only in mind if our eyes point outward, not inward? — NOS4A2

The whole concept may only exist in the mind but the parts on which the concepts are based exist in the external world

When we look at a green tree with three branches, we are looking at one particular instantiation of the concept "tree". When we are looking at a particular set of colours and shapes, we perceive it as being one instantiation of the concept "tree". The concept "tree" does not exist in the world, only in the mind. The instantiation of the concept exists in the world. So we are perceiving two things at the same time, the instantiation of the concept "tree" existing in the external world and the concept "tree" existing in the mind.

But the instantiation of the "tree" that we perceive is made up of parts, consisting of a set of colours and shapes. For example, the colour green, a vertical line, three and a horizontal line.

Searle when discussing the science argument against Direct Realism comments that colours such as red don't exist in the world but only in our own mind. The colour green we perceive doesn't exist in the external world but only in our mind.

When looking at a vertical line, we are again perceiving two things at the same time, a particular instantiation of the concept "vertical line" as a set of points existing in the world and the concept "vertical line" existing in the mind.

Similarly when looking at a horizontal line.

As regards the number three, I would argue that numbers only exist as concepts in the mind, though others would disagree. Though if colours and shapes are concepts, then why not numbers also.

The end result is that when we perceive a green tree with three branches, we are in fact perceiving two things at the same time, a set of points existing in the external world which we determine as a green tree with three branches using concepts existing in the mind.

As Searle writes about intentionality and causality, in belief, validity is achieved when the mind matches the world, and in a valid desire the world must come to match the world. The conditions of satisfaction for an intentional state is self-referential, in that perception has a part of its very meaning that it be a state caused by the object represented in it. Searle would say that I have a visual experience with mind to world fit whose intentional content is that there is a green tree with three branches before me and that there is a green tree before me causing this visual experience.

When the Direct Realist says that they are directly looking at a green tree with three branches in the external world, what this means is that they are perceiving on the one hand a set of point in the external world and on the other hand perceiving concepts existing in the mind.

As Searle asks, how do we avoid scepticism, subjectivism or solipsism if our understanding is through concepts which only exist in the mind. Our knowledge of the world derives from the causal connection between points in the external world existing in time and space and our experience of them, and making sense of these experiences using concepts that exist in the mind perceiving these experiences.

And this is suppose to turn me into indirect realist because of the causal train of events. — Richard B

Pierre Le Morvan in his article Arguments against Direct Realism and how to counter them is making the valid point that a Direct Realist can accept causal indirectness without accepting cognitive indirectness.

But I do not think the direct realist should be concerned about how we perceive, but how we learn and use the word “perceive”, how we make judgements about what we perceive, or how we gain knowledge from what we perceive. — Richard B

Surely a Direct Realist doesn't need to make any judgement when perceiving the colour green, for example, as they directly perceive the colour green. It is the Indirect Realist who needs to make a judgement when perceiving the colour green.

I draw a stick figure of a person from my imagination. I show this picture to a child and ask her "what to you see?" The child may reply, "I perceive a stick figure of a person." Can we not claim that the child directly perceives a picture of a stick figure? — Richard B

Wittgenstein's Beetle in the Box argument can be used against Direct Realism

Wittgenstein uses the beetle in a box to argue that a language understandable by only a single individual is incoherent, ie, his private language argument. Para 293 of PI: "Suppose everyone had a box with something in it: we call it a "beetle". No one can look into anyone else's box, and everyone says he knows what a beetle is only by looking at his beetle." He argues that no one can ever never know the private perception of another, but can only infer it from their behaviour.

If Direct Realism was correct, given a picture of a stick figure in the external world, I would directly perceive the stick figure, and the child would directly perceive the stick figure. This would mean that I would know that my private perception was the same as the child's private perception, and vice versa. But this would contradict Wittgenstein's private language argument.

The famous picture of the "duck-rabbit" is an illusion. If presented to someone, they could see the picture as a rabbit, or, another time, see the picture as a duck. However, could we not say the what we perceive is the same figure in both cases? If so, the positing of sense data has no explanatory power in this case to explain this illusion. — Richard B

The Argument from Illusion can be used against Direct Realism

Searle refers to a similar argument used by the Indirect Realists to argue for the existence of sense data. If you hold up one finger and look into the distance past the finger, you will not see one object but will see two sense datum. This means that it is not the object you are directly looking at but the sense datum. Then, when you look at your finger, it may appear that you are directly looking at an object, but in fact you are are directly looking at sense datum.

When someone looks at a duck-rabbit they can only see either a duck or a rabbit, they cannot see both a duck and rabbit at the same time.

Imagine they see a duck. As before, they look into the distance past the picture and will see not one object but two sense datum. This means that it is not the object they are directly looking at but the sense datum. Then, when they look at the picture, it may appear that they are directly looking at an object, but in fact they are directly looking at sense datum.

He argues that no one can ever never know the private perception of another, but can only infer it from their behaviour. — RussellA

This is incorrect. Wittgenstein is saying that this picture of naming something private drops out as inconsequential in terms of how we understand what is being communicated.

I would directly perceive the stick figure, and the child would directly perceive the stick figure. This would mean that I would know that my private perception was the same as the child's private perception, and vice versa. — RussellA

This is incorrect. See above. Both are perceiving, talking about a publicly shared object. Not providing proof of what they are supposedly perceiving privately.

Imagine they see a duck. As before, they look into the distance past the picture and will see not one object but two sense datum. This means that it is not the object they are directly looking at but the sense datum. Then, when they look at the picture, it may appear that they are directly looking at an object, but in fact they are directly looking at sense datum. — RussellA

But they cannot distinguish between the two “sense datum” of the picture, they are the same. The positing of “sense datum” does not explain why they report a rabbit one time and a duck another. So, “sense datum” has no explanatory power in this case.

This is incorrect. Wittgenstein is saying that this picture of naming something private drops out as inconsequential in terms of how we understand what is being communicated. — Richard B

According to Wittgenstein, in addition to the fact that no one can ever never know the private perception of another, but can only infer it from their behaviour, the object can play no part in the language game. The name "pain" may have a use in a language game, but not as a name for a particular thing existing in the world.

This is incorrect. See above. Both are perceiving, talking about a publicly shared object. Not providing proof of what they are supposedly perceiving privately. — Richard B

From Wikipedia - Naive Realism: Things in the world are perceived immediately or directly rather than inferred on the basis of perceptual evidence. According to the naïve realist, the objects of perception are not representations of external objects, but are in fact those external objects themselves.

An Indirect Realist would need proof, but a Direct Realist wouldn't, otherwise they wouldn't be a Direct Realist. To be a Direct Realist is to subscribe to the idea that their private perception is directly of the public object.

But they cannot distinguish between the two “sense datum” of the picture, they are the same. The positing of “sense datum” does not explain why they report a rabbit one time and a duck another. So, “sense datum” has no explanatory power in this case. — Richard B

Someone may first see a duck and later see a rabbit, but they cannot see a duck and a rabbit at the same time. At one moment in time there can only be one intentional object.

So, “sense datum” has no explanatory power in this case. — Richard B

I think it has explanatory power in the case of the dress that some see to be black and blue and others see to be white and gold. Each person can be looking at the same photo, in the same lighting conditions, and from the same perspective, but given their differences in eye and brain structure, the quality of their visual experiences differ.

One person sees white and gold, and so uses the phrase "white and gold" to refer to what they see. The other person sees black and blue, and so uses the phrase "black and blue" to refer to what they see. In a quite understandable sense, each person is seeing something different. So if each person is seeing something different, despite the shared external world stimulus, then they aren't seeing that shared external world stimulus.

At the very least this shows an ambiguity with the word "see", such that under one meaning they are seeing the same thing and under another meaning they are seeing a different thing. And this is why I think much of the time both direct and indirect realists are talking past each other, and why I think the very question "do we see the object directly or indirectly" is a red herring. The more pertinent question is whether or not colour, shape, sound, taste, etc. are properties inherent in external world objects or are properties that emerge in the act of seeing, hearing, tasting, etc.

Historically at least, direct (or naive) realists would argue that colour, shape, sound, taste, etc. are properties inherent in external world objects, and indirect realists would argue that they're not. And I think our current understanding of the world, at least with respect to colour, sound, and taste, agrees with the latter.

The perceiver and what is directly perceived by the perceiver must be one and the same

The perceiver and what is directly perceived by the perceiver must be one and the same

There is X, the mind, the brain, the little man and there is Y, sense data, representation, idea. X is the perceiver and Y is what is perceived.

If the mind, the brain, or the little man can perceive sense-data, representation, idea, both the perceiver and the perceived ought to be able to stand in direct relation to one another, where one perceives and the other is perceived.

But when we take a mind, a brain, or the homunculus and place it in direct relation to sense-data, representation, or idea, perception cannot be said to be occurring by any single measure. At best we have a pile of decomposing organic material, and, well, nothing else.

What I wanted to do with this thought experiment was to take the idea of a perceiver as postulated by an indirect realist, and add to it the necessary components involved in perception, so that we can finally say "Yes, X is perceiving". If it is unable to perceive, it is not a perceiver.

A brain, for example, for instance in a jar, cannot be said to be perceiving. A brain needs vast quantities of blood, and therefor requires a circulatory system, so we add it. Still, all we have is a pile of decomposing organic material. Brains need oxygen, so we add lungs. It needs energy, so we add a digestive system, a liver, kidneys. Still no perception; still just a pile of decomposing organic material. We add the spine and skeleton so at least it isn't all just lying on the floor. We add neurons, visual, olfactory and auditory organs, but it's all just hanging there as if from a hat rack. So we add a skull, muscles, tendons, and so on. At this point he might be able to perceive, but all of it would be excruciating and our perceiver would be a poor soul indeed. So we add skin, eyelids, ears, and so on. Anyways, you catch the drift.

The point is, perceivers have most if not all of the above. Therefor perceivers are not brains, minds, or homunculi.

I think you've laid out the distinction between DR and IR nicely. My only objection is to the terms "inside" and "outside".

So, I would say DR posits that we have unmediated access to a mind-independent reality, whereas IR posits that we have unmediated access only to a mind-mediated reality.

The mind-mediated reality is also determined in pre-cognitive ways by a mind-independent actuality that cannot be real for us, even though we cannot but think of it as being real in itself.

I think it has explanatory power in the case of the dress that some see to be black and blue and others see to be white and gold. Each person can be looking at the same photo, in the same lighting conditions, and from the same perspective, but given their differences in eye and brain structure, the quality of their visual experiences differ. — Michael

To be clear, I am not arguing the scientific description/explanation of perception but only the metaphysical explanation. From your passage it is not clear which of these you are trying to argue.

One person sees white and gold, and so uses the phrase "white and gold" to refer to what they see. The other person sees black and blue, and so uses the phrase "black and blue" to refer to what they see. In a quite understandable sense, each person is seeing something different. So if each person is seeing something different, despite the shared external world stimulus, then they aren't seeing that shared external world stimulus. — Michael

Many times in human experience, two people can disagree on what they see for many reasons without appeal to "sense data". For example, maybe when someone looks at a duck-rabbit picture they only report seeing a rabbit because they never experience every seeing a duck, thus, there is no need to use "sense data" to explain. Another example, I show a rectangle where at one end it is one color transitioning to the other end into another color. At both ends, most people will judge and agree what the color is. But as we transition we will find less agreement in the middle and maybe sometimes some will not commit to any color. Do I need "sense data" to explain this or just the fact that I created an example to solicit different responses. But maybe thru training, I might eventually get greater agreement. Goodbye again "sense data". Or, scientifically, human beings differ biologically from person to person. Like a color blind person who has difficulty judging between red and green. This is discovered not by asking someone, can you explore your sense data and tell me what color you see, but designing publicly observable samples to see how one judges against accepted responses.

Historically at least, direct (or naive) realists would argue that colour, shape, sound, taste, etc. are properties inherent in external world objects, and indirect realists would argue that they're not. And I think our current understanding of the world, at least with respect to colour, sound, and taste, agrees with the latter. — Michael

Yeah but there is a problem the indirect realist seems to create. Let us say we have a tree outside of a house. We place a video camera to focus on the tree. We hook up some cables and move them into the house where we connect them to a video screen. When I look at the screen, I perceive the image of the tree. I can say "I am looking at it indirectly." Is that because I have this casual train from light to the lens of camera, to the electrons flowing in the wires, etc. etc. etc. Or because, I can go outside and "directly" perceive the tree. But, the indirect realist says, "this is not the same because we do not know what the tree "really" looks like to compare, we only have our "sense data". This makes no sense because the indirect realist suggests that if only we could "directly perceive" something where we are not involved in the perceiving. It is like saying, "what is the color of the tree when there is no light?"

The mind-mediated reality is also determined in pre-cognitive ways by a mind-independent actuality that cannot be real for us, even though we cannot but think of it as being real in itself. — Janus

Are you referring to Innatism, Enactivism, Kant's a priori intuition, etc, in that life has evolved in synergy with the world for at least 3.5 billion years. I agree, if you are.

If the mind, the brain, or the little man can perceive sense-data, representation, idea, both the perceiver and the perceived ought to be able to stand in direct relation to one another, where one perceives and the other is perceived. — NOS4A2

If the mind is the perceiver and the idea is the perceived, and the perceiver and perceived are separate entities, how can the mind ever have knowledge of the idea if the idea is forever separate from the mind?

The point is, perceivers have most if not all of the above. Therefor perceivers are not brains, minds, or homunculi. — NOS4A2

If the perceiver cannot be found in either the mind or the brain, where exactly is the perceiver?

I am not arguing the scientific description/explanation of perception but only the metaphysical explanation. — Richard B

What's the difference? We know that the external world is constituted of things like atoms and electromagnetic radiation. We know that electromagnetic radiation is reflected by bundles of atoms into our eyes (which are themselves bundles of atoms). This stimulates brain activity (which is itself bundles of atoms). This triggers the occurrence of visual or auditory or tactical experience. What else is there to add to this?

Many times in human experience, two people can disagree on what they see for many reasons without appeal to "sense data".

And many times in human experience two people disagree on what they see for reasons that do appeal to sense data, e.g. a dress that one person sees as white and gold and another as black and blue.

Another example of sense data having explanatory power is that of dreaming or hallucinations. I see and hear and feel things when I dream. I'm not seeing or hearing or feeling some external world stimulus. I'm not seeing or hearing or feeling my brain. So what am I seeing and hearing and feeling? I think there are two different, equally acceptable, ways to answer this. The ordinary answer is that I see people and hear music and feel warmth. Of course, these people and this music and this warmth are all "in my head", but I see and hear and feel them all the same. The philosophical answer is that I see and hear and feel sense data.

But, the indirect realist says, "this is not the same because we do not know what the tree "really" looks like to compare, we only have our "sense data". This makes no sense because the indirect realist suggests that if only we could "directly perceive" something where we are not involved in the perceiving. It is like saying, "what is the color of the tree when there is no light?" — Richard B

That is the very question that gave rise to the distinction between direct and indirect realism. We wanted to know if the world "really is, objectively" as it appears to be. The direct realists argued that the world "really is, objectively" as it appears to be, because we see it "directly" (whatever that means). It therefore follows that if the world isn't "really, objectively" as it appears to be, then we don't see it "directly" (whatever that means).

The irony here is that you (and many others) appear to be using direct realist terminology but accept the indirect realist's conclusion regarding the disconnect between how things appear and how they "really, objectively" are. And this is why I said before that direct and indirect realists are talking past each other and that the question of whether or not we see things "directly" is a red herring. To repeat my previous comment: the pertinent question is whether or not colour, shape, sound, taste, etc. are properties inherent in external world objects or are properties of experience. That's the issue that has philosophical significance, and I think our best understanding of the world and perception firmly supports the latter view – which is the essence of indirect realism, even if you disagree with the way in which it's often described ("seeing sense data/internal representations").

What's the difference? We know that the external world is constituted of things like atoms and electromagnetic radiation. We know that electromagnetic radiation is reflected by bundles of atoms into our eyes (which are themselves bundles of atoms). This stimulates brain activity (which is itself bundles of atoms). This triggers the occurrence of visual or auditory or tactical experience. What else is there to add to this? — Michael

Not “sense data”. What is the distinction between metaphysics and scientific explanations. Let’s start with the following definition of metaphysics: “Derived from the Greek meta ta physika ("after the things of nature"); referring to an idea, doctrine, or posited reality outside of human sense perception.” Sure does not sound like what science is suppose to investigated. Ok, now let’s look at a definition of science: “the systematic study of the structure and behavior of the physical and natural world through observation”. Looks like different fields of study. Pragmatically speaking, how do they differ? Well one way scientist will investigate is the utilization of labs, instruments, experiments, and/or data analysis. What about philosophers? They construct arguments. “Sense data” is an argue from ideas of hallucinations and veridical experiences (Argument from Illusion)

Another example of sense data having explanatory power is that of dreaming or hallucinations. I see and hear and feel things when I dream. I'm not seeing or hearing or feeling some external world stimulus. — Michael

This is a conceptual confusion. What we humans do is report that we have dreams. That is how we come to understand this term. I would encourage anyone who wishes to understand this argument to read Norman Malcolm’s book “Dreaming”.

That is the very question that gave rise to the distinction between direct and indirect realism. We wanted to know if the world "really is, objectively" as it appears to be. The direct realists argued that the world "really is, objectively" as it appears to be, because we see it "directly" (whatever that means). It therefore follows that if the world isn't "really, objectively" as it appears to be, then we don't see it "directly" (whatever that means). — Michael

Using words like “direct” and “indirect” have meaning is everyday use. However, the problem here is that both the direct and indirect realist misuse they terms and create great deal of confusion when moved from its ordinary use (as I tried to show with my camera/tree example)

The irony here is that you (and many others) appear to be using direct realist terminology but accept the indirect realist's conclusion regarding the disconnect between how things appear and how they "really, objectively" are. — Michael

I would not say I am arguing for the direct realist position but I am arguing against the metaphysical position of both the direct and indirect realist. Only that the indirect realist has more to argue against, their confusion runs deeper. As for what “appear to be so” vs “what it is really”, again when philosophers take these ordinary terms for their ordinary use, that is when the trouble begins.

What we humans do is report that we have dreams. — Richard B

Because we see and hear and feel things when asleep. That's what dreaming is.

However, the problem here is that both the direct and indirect realist misuse they terms and create great deal of confusion when moved from its ordinary use — Richard B

I agree, which is why it is more productive to ask if things like colour, shape, sound, taste, etc. are properties inherent in external world objects or are properties of experience. That gets to the crux of the real disagreement between direct and indirect realists.

If the mind is the perceiver and the idea is the perceived, and the perceiver and perceived are separate entities, how can the mind ever have knowledge of the idea if the idea is forever separate from the mind?

It cannot.

If the perceiver cannot be found in either the mind or the brain, where exactly is the perceiver?

If human perception involves all of the components I have mentioned, the perciever is invariably a human organism, nothing more nothing less. Brains, minds, and so on, cannot be shown to perceive, and so are not perceivers.

Because we see and hear and feel things when asleep. That's what dreaming is. — Michael

When we sleep our eyes are closed, we do not see things while we sleep. So we hear, maybe, especially if we are a light sleepers, any noise might wake us up. Do we feel, again maybe, we hear someone who is moaning as if they are in pain. When we wake up we may report seeing many things, however, we know this is not true because none of the events reported happened, that is why we call it a dream.

You’re just playing word games. Dreamlng isn’t just something that is reported after waking. It’s something experienced. It’s the occurrence of visual, auditory, tactile sense data. It’s seeing, hearing, feeling.

You’re just playing word games. — Michael

Not word games, this is how we learn and understand the meaning of the word “dream”

You’re just playing word games. Dreamlng isn’t just something that is reported after waking. It’s something experienced. It’s the occurrence of visual, auditory, tactile sense data. It’s seeing, hearing, feeling.

It’s more the absence of sense data, in so far as sense data has any meaning. Lights, sounds, touch—what is given to sense—tend to wake us from sleep.

There is but an interplay of energies, that which perceives an apparent reality is an experiencing energy form. While the surrounding energies play upon this energy-conscious form as one would play an instrument, the melody played/apparent reality; is only heard by the instrument/conscious energy form itself. One knows not whether other energy forms like biology itself are listening to the music of themselves, unaware of their private apparent realities.

Sounds a lot like asking ‘What makes the light shine?’