The indirect realist doesn't say that something inside the man perceives something else (but then you did say you'd come to expect straw-manning, so...)

The concern between direct and indirect realism is about properties, not naming conventions. So it's not about what gets to be called 'tree', it's about whether the properties of whatever we're going to call the perception are given by the external world (directly), or via the internal world (indirectly).

It's a given that external objects are what we're naming. When I use the word 'tree' in conversation, it cannot be a private reference to some model in my head, since the word would thereby have no public meaning. But at the same time, it cannot be argued that the properties of the external object somehow make their way into my actions toward it (speech, interaction, etc) completely untouched by internal mental action on them.

As such, it seems very hard to accept direct realism other than by assuming it relates only to the object of reference. But then it seems impossible to accept indirect realism by that definition.

Likewise it seem impossible to accept indirect realism other than by seeing it in terms of the the steps taken from the external cause to the internal cause of reciprocal action. But in that sense, direct realism is nonsense.

So the argument between them seems like another rather pointless one where each side makes the other look untenable by uncharitable definition... As you have done.

For the direct realist, the man directly perceives a tree — NOS4A2

When looking at a green tree, does the Direct Realist directly perceive the colour green or directly perceive the wavelength 500nm ?

So what does the indirect realist perceive?

I suspect that he directly perceives all of the above, and everything else within his periphery.

So what does the indirect realist perceive? — NOS4A2

The tree. As I said, it's not ab out the name we give to the object. Our naming practices are necessarily public and so necessarily external. Saying "prune that tree" cannot refer to an internal mental state. It want you to prune something in the external world, not my mental state.

No indirect realist is going to say that the object of "prune that tree" is an internal representation. so arguing that way is obviously missing the point.

I suspect that he directly perceives all of the above, and everything else within his periphery. — NOS4A2

What is 'directly' doing here? As opposed to what?

If I get a message from you, I could get it 'directly' (from you to me) or I could get it indirectly (via a third person). It is still the message I'm getting. The difference is the degree to which it may have been tampered with, the veracity...

So to claim 'directness' in the sense of 'no possibility of being tampered with', no stepwise progression, is clearly wrong. A cursory glance at the way perception works in the brain would show that.

Then who or what perceives the tree?

Then who or what perceives the tree? — NOS4A2

A person. When we use the expression "John saw a tree" we're clearly talking about a person and a tree. We're not saying "some part of John saw some other part of John". This is obvious from our expectation of the outcome of a sentence like "John, go and cut down that tree".

I know that’s not what you’re saying. I just want to know what John is directly perceiving to the indirect realist. If John is not directly perceiving the tree, what is it that he directly perceives?

I just want to know what John is directly perceiving to the indirect realist. If John is not directly perceiving the tree, what is it that he directly perceives? — NOS4A2

Nothing. John does not 'directly' perceive anything because perception is not a direct process. In much the same way as the answer to the question "which messages do I directly receive through the telegram" would be "none - the telegram is not a direct messaging service".

It was my understanding that for indirect realism there is a perceptual intermediary between perceiver and perceived. If there is none then the distinction between direct and indirect realism is redundant.

For perception to occur at all, something direct has to happen somewhere, otherwise we get an infinity of intermediaries, no? I think that's what @NOS4A2 might be challenging the non-direct realist to tackle. Could be wrong.

For me, a thing only perceives modifications of itself. And as the self is self-identical, there is no intermediary. If a bomb goes off two feet away from you, but it doesn't alter your body in any way, you haven't perceived it. That's my suggestion anyway.

EDIT: Is this a version of the 'extended mind' idea? Don't know. I should probably DuckDuckGo it.

You’re right. I also challenge them to instantiate who and what are the objects of this relationship.

For me, a thing only perceives modifications of itself. And as the self is self-identical, there is no intermediary. If a bomb goes off two feet away from you, but it doesn't alter your body in any way, you haven't perceived it. That's my suggestion anyway.

That’s where I’m at too.

You’re right. I also challenge them to instantiate who and what are the objects of this relationship.

For me, a thing only perceives modifications of itself. And as the self is self-identical, there is no intermediary. If a bomb goes off two feet away from you, but it doesn't alter your body in any way, you haven't perceived it. That's my suggestion anyway.

That’s where I’m at too — NOS4A2

In an optical illusion, a picture of a three-dimensional object is presented with gaps in it. The illusion is that viewers dont see the gaps. They fill them in. Where doesn’t this filling-in come from? It comes from memory. A figure is drawn in the dirt. Someone sees it as a series of squiggly lines. Another sees it as a chinese word symbol. Would you agree the person seeing the image as a word is filling in from memory what is not actually being perceived from the world, similarly to the optical illusion? If I think I see a tree ahead of me , and on closer inspection it turns out to be something else, am I filling in from memory what I am not actually perceiving? The process involved in filling in would be a melding of information coming from the receptors and that coming from memory. Does that sound reasonable to you?

It was my understanding that for indirect realism there is a perceptual intermediary between perceiver and perceived. If there is none then the distinction between direct and indirect realism is redundant. — NOS4A2

I don't know of any version of indirect realism which claims some 'other object' in the brain is what is being perceived.

The distinction is not though redundant. As I said, it's about the degree to which the various steps of the perception process make up the properties of the object.

I suspect a direct realist would like to say there is such a thing as a tree and it's 'correct' properties might be found out by the process of perception or not (if the process isn't working well).

A moderate indirect realist would prefer to say that the 'correct' properties of the object of perception are partially a social construct. I'm incorrect about my perception to the degree I don't conform to that. But partially related to some external constraints on what those object properties can be. (this is my position, by the way).

The more extreme indirect realist would want to say that the perceived object is entirely a dynamic and continually 'being formed' construct created as a collaboration between us and it (we interact with it, form ideas about it, impose those ideas on it etc).

In none of these cases (that I know of), is it claimed that the actual object about which the perception is the subject resides in the head.

For me, a thing only perceives modifications of itself. — bert1

Why do you think that?

I have no satisfying answer to the argument from illusion. But if perception is decidedly direct, it seems to me that any hallucination or illusion is the result of some act or reflex of the perceiver and not of the perceived. I don’t think any of this precludes direct realism.

Yeah I assumed sense-data, ideas, representations, or whatever else is posited as a perceptual intermediary exists within the perceiver for the simple reason they cannot be found anywhere else. If you can suggest a better location I’m all ears.

I have no satisfying answer to the argument from illusion. But if perception is decidedly direct, it seems to me that any hallucination or illusion is the result of some act or reflex of the perceiver and not of the perceived. I don’t think any of this precludes direct realism. — NOS4A2

My point is that the filling in from memory that I associated with illusion is always operative when we perceive something. Perceptual psychologists tell us that most of what we see when we recognize objects is filled in from memory. What we actually take in though our sense receptors is very informationally impoverished.

I’m staring at a flower pot right now and I fail to recognize any impoverishment in what I perceive, nor how memory is informing it. I’ll look into it, though.

Perceptual psychologists tell us that most of what we see when we recognize objects is filled in from memory. What we actually take in though our sense receptors is very informationally impoverished. — Joshs

That seems to match my experience. How many times have I seen something and realized a second later that it was not the thing I thought I saw? Heaps. Anticipation and memory seemed to co-create what is in front of me.

Yeah I assumed sense-data, ideas, representations, or whatever else is posited as a perceptual intermediary exists within the perceiver for the simple reason they cannot be found anywhere else. — NOS4A2

Well there is your stepwise route. Perception is not a direct process. Whatever data is gathered from the external system is passed through several internal stages at each of which data other than from the (current) external state is allowed to modify the prediction of the external state used in, for example, speech about it, or interaction with it.

The process is not direct.

The more extreme indirect realist would want to say that the perceived object is entirely a dynamic and continually 'being formed' construct created as a collaboration between us and it (we interact with it, form ideas about it, impose those ideas on it etc).

In none of these cases (that I know of), is it claimed that the actual object about which the perception is the subject resides in the head. — Isaac

Interesting. The latter would be idealism, wouldn't it?

Whatever data is gathered from the external system is passed through several internal stages at each of which data other than from the (current) external state is allowed to modify the prediction of the external state used in, for example, speech about it, or interaction with it.

The process is not direct. — Isaac

It seems that the issue is where do we draw the line between indirect and the idea that 'materialism' is an illusion created by perception?

In my mind the “internal stages” are a part of the perceiver and thus mediated by him. I don’t see why we need to include some other intermediary. If there is no intermediary the perception is direct.

The latter would be idealism, wouldn't it? — Tom Storm

I think so. Not my wheelhouse.

It seems that the issue is where do we draw the line between indirect and the idea that 'materialism' is an illusion created by perception? — Tom Storm

Yes, that's right. I subscribe to a version of perception which is a kind of collaborative process of continual interaction between a system and the data points which lie outside that system. In one direction, the system tries to predict the external causes of its boundary states, in the other it tries to act upon those states to make them more closely match those predictions.

Such a model is predicated on there being actual external states, but not on them being of any fixed form.

In my mind the “internal stages” are a part of the perceiver and thus mediated by him. — NOS4A2

Well, that's just wrong. If I hit your knee your lower leg will rise. The process is entirely internal. You don't 'mediate' it in any way whatsoever. It's happening in an exactly predictable and consistent manner no matter what you think of it.

If we were to remove both those things from the man, both the perceiver and the perceived, place them on a table next to each other for observation, what would be there? — NOS4A2

You can't stand outside the act of cognition. Put another way, you can't cognise the cogniser. The act of cognition involves subjective and objective poles, but both of those poles arise as aspects of the conscious act. But framing the question the way you have introduces a kind of realist premise which is not commensurable with the kind of question you're asking, you're trying to treat 'the perceiver' as an object, which it never is.

In an optical illusion, a picture of a three-dimensional object is presented with gaps in it. The illusion is that viewers dont see the gaps. They fill them in. Where doesn’t this filling-in come from? It comes from memory. — Joshs

Notice this graphic from physicist John Wheeler's essay Law Without Law



This was in the context of the construction of scientific theory, but I think it can be generalised.

Anything internal is me, though. What else mediates it?

Such a model is predicated on there being actual external states, but not on them being of any fixed form. — Isaac

Really interesting. Do you believe that from this position there is a 'reality as it is in itself' or do you consider such a term incoherent - 'reality' being a constructivist process, dependent on a point of view for its meaning?