If you show me a tree and say "This is the one tree that stands before us", then I am in common-sense agreement. This generally means that I am automatically interpreting your proposition as referring to my frame of reference and to my frame of reference only.

However, I can also understand your proposition as referring to your frame of reference rather than mine. In which case, the number of trees depends upon the general consideration as to whether the reference of a proposition is taken to be relative to perspective.

If I interpret you as referring to either mine or to your frame of reference but not both, then it remains true that "there is one tree that stands before us", however it is semantically indeterminate as to which tree (i.e. which perspective) is being referred to the proposition.

On the other hand, if the reference of this proposition is considered to entail both perspectives then it is no longer the case that we can say that there exists only one tree, for there are two distinct perspectives.

Memorialized in song by Donovan, of course.

I was hoping you'd drop by. Is your take on the conversation about realism informed by Austin and Searle?

My memory is that you would have no truck with the idea of a tree 'as it is in itself', finding this qualifier redundant.

Do you agree with Searle's account of 'the bad argument' as being a key fallacy driving these sorts of discussions that inevitable end up talking about visual illusions, etc?

Is there a fallacy found in that we are not seeing the seeing, the visual experience?

What do you say to the person who asserts that when a human regards an object, that object is to a greater or lesser extent created in the experience of perception, which brings with it anticipatory notions and memories, along with a particular cognitive apparatus which sees colours and other attributes which are present in the experience of looking but not in the object being seen. I've never known where one can stop with this (idealism I guess) and why it matters, except as a problematic foundational argument for a particular ontological position.

Since it was so important, we developed machines, more sensitive and accurate than humans, that could detect the green color of objects. So light would come in and the machine would report and answer “green”. Is the machine having a sensation or constructed perception of “green” to detect the color of “green” in order to report “green”? — Richard B

The leaf is green because it does not absorb the green wavelength. If it is not, what color is it? If you say there is no color, well OK feel free to define “what it really is” any way you like, maybe it will have some interesting utility for us. — Richard B

A wavelength does not have an inherent colour, though any set of wavelengths can be given the name of a colour. The wavelength between 570 and 500 nm has been named "green", though it equally well have been named "vert".

A machine may be programmed such that if its input is 570 to 500nm its output is "green", though it could equally well have been programmed such that if its input was 530 to 420 nm its output was "xyz".

Rather than say " The leaf is green because it does not absorb the green wavelength", one could also correctly say "the machine gives the output green because its input was between 570 and 500nm due to that being the wavelength the leaf did not absorb".

As regards language, I would say that the machine is able to sense a wavelength but is not able to perceive it.

Well, the core of the bad argument is pretty much what was done with 's picture: the supposition that there is more than one tree in the picture. Seems was making a joke.

The naive/direct realist believes the perceiver is perceiving the tree exactly as it is, — schopenhauer1

Nuh. Direct realism is where what we talk about is the tree, not the image of the tree or some other philosophical supposition.

Direct realism is where what we talk about is the tree — Banno

I would have thought that was botany. Or forestry.

Rubbish. You've been around the forum long enough to know we talk of cups and trees and kettles.

The naive/direct realist believes the perceiver is perceiving the tree exactly as it is,
— schopenhauer1

Nuh. Direct realism is where what we talk about is the tree, not the image of the tree or some other philosophical supposition. — Banno

Same thing bro.


Also,

In philosophy of perception and philosophy of mind, naïve realism (also known as direct realism, perceptual realism, or common sense realism) is the idea that the senses provide us with direct awareness of objects as they really are. — Wiki

Direct realism’ (also known as ‘common sense realism’ or ‘naïve realism’) is the idea that our senses provide us with direct awareness of objects as they really are. The ‘directness’ part of the claim captures well our common sense intuitions of direct perceptual access to the world. However, as the term suggests, ‘direct realism’ also makes the ‘realism’ claim, which is that the existence of the world of objects is not dependent upon it being perceived. — https://philosophynow.org/issues/146/Against_Direct_Realism

There's only 1 tree of course, but the point is the representation of the tree, the image on the retina, is, well, true (direct realism) or embellished (indirect realism). — Agent Smith

And that’s my point. What “true” here mean? See my reply to @Banno.

Yes indeed, much different conception from Mr. Schop and one I like to delve into but so far in this discussion keeping it mild by just starting with indirect realism

Is the brain perceiving the process, then? — NOS4A2

The brain is a conglomeration of processes which, working together is the perceiving.

Which tree do we perceive? And who is perceiving that tree? — NOS4A2

All that picture does is demonstrate the mechanics of human vision, from which the answer to that question is impossible, insofar as both forms of realism must accept that physiology.

Remove the word “tree”, then ask where and when the warrant for putting anything in its place, comes from.

Now let the games begin.

For direct realism, the perceiver directly perceives the world, and thus we are able to distinguish between the perceiver and the things upon which he is directing this activity. For the indirect realist, the perceiver directly perceives sense data, ideas, impressions, representations, models, sensations—internal flora and fauna indistinguishable from the perceiver himself—leaving us no distinction between perceiver and perceived. So it’s like saying we perceive perceptions, we see seeings, or we feel feelings. In order to answer the question of what we are directly perceiving, one must posit something that is not the perceiver to find it. Since indirect realism is unable to do so, indirect realism is redundant. — NOS4A2

The argument is that as the Indirect Realist directly perceives sense data, this leaves no distinction between perceiver and perceived, meaning that the Indirect Realist would be unable to perceive any external world. However the same argument would apply also to the Direct Realist, who also directly perceives sense data, but claiming that sense data is veridical and coincides with reality.

Sense data exists in the mind and is perceived by the mind. If Direct Realism is able to transcend its perception of sense data to the objects in the world that are its cause, then similarly so could Indirect Realism.

For the Direct Realist:
1) We directly perceive sense data
2) There is an external world
3) Sense data is caused by the external world
4) We directly engage with objects in the world using the perceptual intermediary of sense data.

For the Indirect Realist:
1) We directly perceive sense data.
2) There is an an external world
3) Sense data is caused by the external world
4) We indirectly engage with objects in the world using the perceptual intermediary of sense data.
5) From these sense data we construct an internal representation of objects in the world
6) There is a direct causal link from objects in the world, to our sense data and to our perception of these sense data.
7) The fact there is a direct causal link from object in the world to our perception of it in the mind does not mean that we can necessarily have direct knowledge of what is in the world. For example, from the fact that there is a storm, the wind blows, a tree sways, a branch hits a window and the glass breaks it does not follow that when we see broken glass we know the cause was a storm. There is a direction of causation from storm to broken glass. Knowledge of backward causation from broken glass to storm is not possible.

Good

But, is this direct or indirect realism really? Direct realism I would say is about knowledge of the world, not mechanism of the knowledge. The mechanism is agnostic (sense data, or Y or Z). All that a statement needs to fall under the class “direct realism”, is that the mind is perceiving an exact replica of what the tree is externally, “in the world”.

An indirect realist might also use the sense data mechanism, but as long as that sense data is in some way changing the tree into its own schema of that tree, it is indirect.

Of course sense data alone is too basic in both cases but it’s just an example of how that can remain constant and the argument doesn’t change for either.

Direct realism I would say is about knowledge of the world, not mechanism of the knowledge. The mechanism is agnostic — schopenhauer1

I agree that in one sense the Direct Realist is looking at a tree in the world , not at the sense data in the mind. They are "looking through" the sense data to the tree on the other side of it, as one looks through a window to the world outside.

However, if someone somehow removed the sense data from the brain of the Direct Realist, they wouldn't be able to see the tree.

In another sense, the Direct Realist is directly looking at something that is at the same time both sense data and a tree. This could be part of the argument against Direct Realism, in that the Direct Realist is perceiving something which is in fact sense data although they think it is a tree, ie, a psychological illusion.

I agree that in one sense the Direct Realist is looking at a tree in the world , not at the sense data in the mind. They are "looking through" the sense data to the tree on the other side of it, as one looks through a window to the world outside.

However, if someone somehow removed the sense data from the brain of the Direct Realist, they wouldn't be able to see the tree.

In another sense, the Direct Realist is directly looking at something that is at the same time both sense data and a tree. This could be part of the argument against Direct Realism, in that the Direct Realist is perceiving something which is in fact sense data although they think it is a tree, ie, a psychological illusion. — RussellA

:up: Yeah this sounds like a good synthesis of the landscape.

I think the bigger picture is not the epistemology but the metaphysics. What are "physical properties" really? How do physical properties obtain without a perceiver? What is an event without an perceiver? Is it space-time that becomes the placeholder for the event to obtain? Here comes idealism creeping in slowly...

There are three scenarios, each arguing against Direct Realism.

Scenario one
I just perceive the colour green. As anything could have caused it, this is an argument against Direct Realism which is the position that its cause would be known.

Scenario two
Over the recent past I had seen a tree and perceived the colour green. Today, I just perceive the colour green. I infer that the cause of my perception of green is a tree, but as inferences may be wrong, my knowledge that the cause is a tree can only be indirect. Another argument against Direct Realism which is the position that its cause would be known.

Scenario three
I see light from the sun hitting the leaves of a tree, green light is reflected and enters my eye which I perceive as green. I know the causal chain that started at the sun and ends up with my perception of green. But each stage in the causal chain has the same problem: I perceive white, how do I know that it was caused by the sun, I perceive green, how do I know it was caused by the leaves. If the question is, when I perceive a green tree how do I know it was caused by a green tree, the fact that there are many stages in a causal chain doesn't ensure a solution if each stage suffers from the same problem, how do I know what caused my perception.

The problem of knowing the cause of my perception of the colour green is the same problem as how I know the cause of the broken window seen on my walk into work. Causation is directional from the sun to my perception of green. Backwards causation is impossible. Even though one knows the final stage of a causal chain, it would be impossible to discover how the chain was initiated, in that for each effect there will be several possible causes.

And yet one "knows" that the green tree I perceive in my mind was caused by a green tree in the world. The mind must equate effect with cause. If I perceive green the cause was green, if I perceive a tree the cause was a tree, if I perceive a green tree the cause was a green tree.

For the mind, it seems to me, it is not that we directly attend to objects in the world that are independent of us, as in Direct Realism, rather we directly attend to our sense data which we equate with what exists in the world, as in Indirect Realism.

The brain is a conglomeration of processes which, working together is the perceiving.

But there are more organs and more biology involved in perceiving.

All that picture does is demonstrate the mechanics of human vision, from which the answer to that question is impossible, insofar as both forms of realism must accept that physiology.

Remove the word “tree”, then ask where and when the warrant for putting anything in its place, comes from.

Now let the games begin.

Anything that is the “mechanics of human vision” is itself the perceiving, and not the perceived. If indirect realism accepts this it is redundant.

How do physical properties obtain without a perceiver? — schopenhauer1

I can discover in the world several shapes that are square at the top and round at the base.
I can invent the physical property "squund", which is a shape that is square at the top and round at its base. As a property is a concept, it cannot exist in the world. Although there may be particular instantiations of the property squund in the world, an instantiation of a property is not a property.

Therefore, physical properties cannot obtain without a perceiver.

What is an event without an perceiver? — schopenhauer1

Unperceived.

Is it space-time that becomes the placeholder for the event to obtain? — schopenhauer1

There's nothing else apart from space-time that could be a placeholder.

Let's say I work at the hadron collider institute in Geneva, using the sophisticated machinery I witness subatomic particles interact at the smallest fractions of time. I go outside and encounter an ancient carving on a stone never before seen. Then I look up into the clear night sky and witness the light of a thousand stars streaming into my eyes.

What is the scope of my observations in the past hour?
I've observed information from the most minute, brief moments of the present, I've observed information from ancient humans carved on stone, and I've observed information millions of light years old coming from the stars, the great beyond.

My scope of of awareness here spans eons. I am observing both the immediate quantum interactions and space at large and everything in between.

Where does my awareness end and external unobserved information begin? This dynamic changes constantly.

The sphere of awareness is not fixed but always changing. But it all takes place in a self referential timeframe of "my present" not the present moment from which the any of the above outlined information originated. As info takes time to travel distance.

These are some examples of the Interplay between time and awareness. I don't know if this is useful to your inquiry but its one line of thinking for you to consider.

But there are more organs and more biology involved in perceiving. — NOS4A2

Yep, sure are. And by me adding this to the equation, what exactly would that be adding to the problem? We already have X brain and sensory components I mentioned, add more, and what changes? We already have various filters I have mentioned.

I think the beetle/box language game thing can be parked, but I guess you are saying that although humans 'create' green - it is not out there in reality - what is out there in reality is a particular light frequency that we experience as green. This can be objectively tabulated as a quality of the external world — Tom Storm

First, my response would be, "I perceive trees", "I perceive green leaves", etc. Second, I would not say, "I perceive sense data of trees, green leave" etc. Second, I am not sure if I would use the word "create" unless this means we came up with the word "green" to communicate with our fellow humans about a particular color. Additionally, I think indirect realism and direct realism share a similar problem in that these positions can be concerned with arguing about objects "as they really are". For example, just take these two definitions:

1. direct realism: the idea that the senses provide us with direct awareness of objects as they really are.
2. indirect realism: the idea that we do not perceive the external world as it really is, but know only our ideas of the way the world is

To say, "I directly perceive the tree" sounds redundant to "I perceive the tree", unless you want to set up the comparison with "I indirectly perceive the tree in a mirror." But to say only say "I directly perceive a tree as it really is" seems to have go down the path of philosophical confusion. Could you give it meaning? I suppose you could, and maybe if there is enough agreement in judgment your got agreement in the form of life, for example, scientific theory of color.

Lastly, if what you say, "what is out there in reality is...", means just that our current scientific theory says the color "green" has a particular wavelength and we can talk about the color "green" with each other, OK I am good with that.

I will leave you with what Wittgenstein say in Philosophical investigations, "'So you are saying that human agreement decides what is true and what is false?' It is what human beings say that is true and false; and they agree in the language they use. That is not agreement in opinions but in form of life."

Yep, sure are. And by me adding this to the equation, what exactly would that be adding to the problem? We already have X brain and sensory components I mentioned, add more, and what changes? We already have various filters I have mentioned.

Everything standing in the way of our direct perception disappears. There is nothing between perceiver and perceived.

Although there may be particular instantiations of the property squund in the world, an instantiation of a property is not a property. — RussellA

Can you elaborate on this, defining instantiation here, and property and why one instantiation of property is not property? I may agree, but just want to see if I understand your thought here first.

What is an event without an perceiver?
— schopenhauer1

Unperceived. — RussellA

That really doesn't help though. That is simply rephrasing the problem, "What is an event that is unperceived" then?

There's nothing else apart from space-time that could be a placeholder. — RussellA

But I guess, what does that even mean for space and time to be a placeholder for an event sans perceiver?

Everything standing in the way of our direct perception disappears. There is nothing between perceiver and perceived. — NOS4A2

How is that related conclusion occurring by adding more biological components (or any at all)? You are simply restating a claim and then not refuting the counterargument (the components of the body are configuring the tree for the person seeing it).

Neither your configured tree or your perceiver can be instantiated. You are beginning to speak of things that either do not exist or do not perceive.

Not getting what you are saying other than (unintentionally) vague allusions to Idealist arguments (the tree is just and idea and not external, etc.).

I want to know what perceives and what is it perceiving. The only thing I can glean from your posts is that the brain is viewing a configured tree.

the brain is viewing a configured tree — NOS4A2

Correct, according to the current scientific account- the perceiver is the culmination of various brain and body processes. This collection when discussing the question, "What is it that is perceiving X", is the proper locus for what can be called "the perceiver". In general human parlance, this is often called "perception" or other cognitive psychological placeholder term.

What is configured is the qualia, and conceptual associations that go along with said brain processes. I mean, if we want to venture into the mind-body problem, be my guest. I've done it on this forum many times, and I'm often the one contrary to the typical materialists, so make my day. But, before you jump to the "hard problem", I would like to at least recognize that there are indeed "easy problems", which you seem to be dismissing.