What matters is that the situation you're imagining is just a collection of shapes and colours and smells and whatnot. These aren't perspective-independent things. So what you're imagining is not a realist thing. — Michael

But you are not imagining a collection of shapes and colors: you are imagining a tree. You can assert a tree is nothing but this, but this assumes the conclusion.

Whether or not there's an experiencer in the imagined situation is irrelevant. Just as whether or not there's an author in the book I've written (about a book) is irrelevant. The thing I've written about (a book) isn't the sort of thing that can exist without being written. — Michael

It is relevant because the logic of the argument doesn't go through. You can stipulate that it doesn't matter because all situations are purely experiential situations, but this assumes the truth of idealism, and so is not an argument for it.

To make the analogy clear, the claim is as if you were saying that because every story requires a writer, it must be that all situations that stories describe are ones with writers in them. This of course is false, just as it's false that in all situations that are conceived, or imagined, there must be a conceiver or imaginer in those situations. You can then stipulate that all stories have books in the story (false), or that all situations themselves have experiencers (idealism), but the latter requires assuming idealism, and so you no longer have an argument. The conclusion goes through because you have assumed it, not because of the structure of the argument – the argument itself is fallacious.

But you are not imagining a collection of shapes and colors: you are imagining a tree. You can assert a tree is nothing but this, but this assumes the conclusion. — The Great Whatever

I'm not assuming the conclusion. I'm describing what I'm doing. When I imagine a tree I picture one in my mind. I imagine what a tree looks like and feels like and smells like. I then recognise that this is just a collection of experiential things. If someone were to ask me to imagine a tree but not imagine any of this then I quite literally come up blank.

I'd be surprised if anyone did anything else when imagining a tree.

Is a tree just a collection of experiential things?

If yes, you've assumed your conclusion.

If no, then in imagining a tree you have not just imagined a collection of experiential things, but a tree.

Whether you have experiences in imagining a tree is irrelevant.

Is a tree just a collection of experiential things?

If yes, you've assumed your conclusion. — The Great Whatever

Again, it's the conclusion, not the assumption. I've come to that conclusion by imagining a tree and then analysing this imagination. It turns out that when I imagine a tree I'm just imagining the look and feel and smell of a tree. Take this all away and I come up blank. And, again, I'd be surprised if anyone could do anything else.

I deny that in imagining a tree you are only imagining a tree's smell, etc.: you are, rather, imagining a tree. Its smell, etc. may be salient properties of it, but they're not equivalent to the tree, unless you assume your conclusion.

For example, if I'm told to imagine that a man chopped down seventy trees illegally and was sent to prison, I can do this fairly easily, but it's unclear to me exactly what sorts of smells and sights I am or have to be imagining, and those things seem not to be at all what's most relevant or present to my mind in imagining such a scenario (how tall are the trees? are they elms, or pines? what is the man wearing? what does the prison look like?). I'm not even sure I can consistently picture seventy trees together (as opposed to sixty-nine, after all), as if all in a visual or olfactory image. Yet I can imagine such a situation without difficulty: so you must be wrong.

For example, if I'm told to imagine that a man chopped down seventy trees illegally and was sent to prison, I can do this fairly easily, but it's unclear to me exactly what sorts of smells and sights I am or have to be imagining, and those things seem not to be at all what's most relevant or present to my mind in imagining such a scenario (how tall are the trees? are they elms, or pines? what is the man wearing? what does the prison look like?). I'm not even sure I can consistently picture seventy trees together, as if all in a visual or olfactory image. Yet I can imagine such a situation without difficulty: so you must be wrong. — The Great Whatever

I would say that if you're not picturing it then you're not imagining it. You're just understanding the meaning of the sentence.

Then you are using the word 'imagine' to mean 'picture solely experientially,' which would seem to linguistically guarantee your conclusion. All I can do is protest that this isn't what 'imagine' means, at least not if you want to marshal any of the relevant idealistic conclusions.

(At the very least, it would commit you to saying I can't imagine a man chopping down seventy trees, too strong a conclusion if this is supposed to imply that a man chopping down seventy trees is unimaginable and therefore somehow impossible).

At the very least, it would commit you to saying I can't imagine a man chopping down seventy trees, too strong a conclusion if this is supposed to imply that a man chopping down seventy trees is unimaginable and therefore somehow impossible — The Great Whatever

I didn't say that you can't. You just said that you weren't. I'm sure if you took the time you could imagine a man cutting down seventy trees.

Then you are using the word 'imagine' to mean 'picture solely experientially,' which would seem to linguistically guarantee your conclusion.

But I think the problem is that many realists do claim to be able to picture a tree that isn't being seen and that this thing they're picturing is coherent and a real thing in the world. Which, some would argue, is as mistaken as imagining a book without an author and thinking that this is a coherent and real thing in the world.

But I think the problem is that many realists do claim to be able to picture a tree that isn't being seen — Michael

They say you can picture such a thing because you can. If you are picturing a tree, the fact that you are picturing it in the imagining situation does not mean that anyone is picturing it in the pictured situation. This is the formal fallacy.

To think otherwise would be effectively to claim that every picture than an artist paints contains the artist in the picture: not every picture is a picture of the painter, just because you must paint in order to picture.

Back to this. Perhaps the realist can say the idealist is making a mistake here in insisting that the realist be able to imagine what something is like independent of perspective. We can't do that because we're human beings who always perceive from a certain perspective. — Marchesk

It is thus not inconceivable to imagine a situation in which no one is perceiving a forest, and to think this is not possible is to fundamentally misunderstand how imagining scenarios works. — The Great Whatever

Truth statements depend on perspective. What we say about what exists and what doesn't exist relies on perspective. I can perfectly well imagine the early earth, where for hundreds of millions of years, forests grew and trees fell before there were even mammals, let alone humans, but even to imagine it relies on a perspective and the human sense of time and scale. The mind organises perceptions, sensations and judgements into a cognitive whole - and that is what 'the world' is, to thinking beings such as ourselves.

Put the word 'idealism' to one side for a moment. When we speak about reality at all, what are we referring to? 'The world', 'the universe', and so on; nowadays science has given us a pretty good idea of the actual scope of the word 'universe'. But whatever we see, measure, observe, etc, ultimately, as perceiving beings, what we speak of comprises perceptions, cognition, judgements, measurements, and the rest'; it is all 'patterns in the neural matter'. The human brain is the most complex known natural phenomenon, and it's output is what we understand as 'the world'.

But don't forget that Kant was able to declare himself an 'empirical realist'. He took pains to distinguish his philosophy from that of Berkeley, which he called 'material idealism' or 'problematic idealism'. So Kant is not arguing simplistically that the universe has no reality outside perception, but that human faculties play an inescapable role in whatever we understand as reality.

Through the quantitative methods of science, we are able as far as possible to identify the mathematical laws and regularities that are the same for all observers, and to apply similar techniques of quantification to all manner of subjects.

But what historically occurred is that, arising from the philosophy of Locke, Newton, Galileo, and the other founders of modern scientific methodology, 'mind' came to be regarded as being of derivative importance, located among the 'secondary qualities', as distinct from the 'primary qualities' which were regarded as the proper objects of measurement by the natural sciences (in other words, those things that really exist. This is elaborated at length by E A Burtt The Metaphysical Foundations of Modern Science.) Hence the attitude (which is nowadays quite instinctive) of 'objectification' - the requirement to seek answers in terms of the purported 'objective data' and quantification.

But all of this is still a human undertaking. The human sciences rely on a human sense of time and space - Kant's 'primary intuitions'. Because of rational thought and mathematics, humans can rise to an understanding that is different in kind to anything that non-rational animals are able to do, but science is still a human undertaking. And I think that is what Kant identified: the Critique of Pure Reason is the necessary corrective to scientific materialism.

And that's why I referred earlier on the the Bohr-Einstein debates (as explained in http://a.co/dsthstv). Einstein was deeply perturbed by the apparent 'mind-dependence' of quantum objects; that is why he asked 'Does the moon still exist when we're not perceiving it?' He was a stalwart scientific realist - the universe exists and we're trying to understand its fundamental constituents, which ought to be 'there anyway' in his view. Whereas Bohr and Heisenberg had (in my opinion) a much more philosophically nuanced understanding of the issues, and they were also considerably more modest. I think they they understood the limitations of knowledge in respect of such questions as the 'ultimate constituents of being'; Heisenberg ultimately published several well-regarded books on physics and philosophy which were also, broadly speaking, idealist in attitude. (Athough Heisenberg's reputation has suffered - rightly - from the fact that he was in charge of Hitler's atomic bomb program.)

Anyway, that's all a long digression, but my considered view amounts to saying that the Universe has an ineluctably subjective pole; reality can't be said to consist solely of objects. You have to understand this whole subject historically, in terms of the 'history of ideas' that has developed from medieval to modern times.

They say you can picture such a thing because you can. If you are picturing a tree, the fact that you are picturing it in the imagining situation does not mean that anyone is picturing it in the pictured situation. This is the formal fallacy. — The Great Whatever

It doesn't matter if there isn't anyone in the picture, just as it doesn't matter if there isn't an author in the story. The thing being pictured/written about cannot be part of the real world without there being an experiencer/author (according to the idealist when it comes to the tree being pictured, presumably everyone when it comes to the book). Strictly speaking the situation makes no sense.

Remember that this isn't just a hypothetical imagining. The realist claims that something in the world "matches" the imagined situation; that the imagined situation is (or could be) of a real thing. And that can't be true if the thing you're imagining is experiential in nature. It would be like imagining being in pain and thinking that this pain is somewhere out in the world to be found.

I'm not even sure I can consistently picture seventy trees together (as opposed to sixty-nine, after all), as if all in a visual or olfactory image. Yet I can imagine such a situation without difficulty: so you must be wrong. — The Great Whatever

When you say "I can imagine such a situation without difficulty", are you really sure that you can, or are you just saying that? Did you try to actually imagine that situation? If so, how did you do so without trying to picture it?

I can conceive of building a starship and traveling to a nearby star, but I can't actually imagine it. Hasn't stopped people from writing stories about it.

Being able to visualize and being able to conceive are separate abilities.

Right, imagining something, and conceiving something, are two distinct things.

Right, but then you're back to assuming your conclusion. The realist will just deny that they're imagining experiences. They'll say they're imagining a tree, and part of that imagination might involve them having experiences in the imagining situation, but this is irrelevant. Not sure where your argument is supposed to go from there, unless we futz around with the semantics of 'imagination,' which doesn't seem promising.

When you say "I can imagine such a situation without difficulty", are you really sure that you can, — Metaphysician Undercover

Yes

Haven't the people who wrote stories about it imagined it?

Haven't the people who wrote stories about it imagined it? — John

Yeah, seems like imagined, visualized, pictured, and conceived are all getting jumbled together. So, I don't think any human can actually visualize a trip to a nearby star, but they can imagine a story in which a trip is made, or perform the calculations for the propulsion system based on estimated weight of ship, crew, food, etc.

This tangent got started by the claim that you don't need to be able to picture cutting down 70 trees to conceive it. One can simply perform the math of cutting down 70 trees for the average human with an axe or chainsaw. It's not a problem for the reality of cutting down that number of trees.

1. The world is pretty much as we perceive it (naive realism, direct realism?)
2. The world is pretty much as science illuminates it. (scientific realism)
3. The world is mathematical. (Tegmark, Meillassoux)
4. The world can only be known in its relations. (object-oriented realism)
5. The world is unknowable, but it's still real. (Kantian noumenon)
6. This isn't a meaningful question. (Wittgenstein, quietism, deflationary, positivism) — Marchesk

And this matters because? Will knowing that subjective idealism is true cause us to behave any differently, or relate any differently to the world? Certainly not. All this is about is which is the simplest way of comprehending reality, which one requires the fewest assumptions. Probably this is some form of idealism.

And this matters because? — Agustino

It matters the same reason for asking any sort of questions about existence. How do we get here, how big is the world, did it have a beginning, and so forth. Humans have this curiosity about such questions. And some of the proposed answers bother us, and are preferably avoided.

It may not affect our daily routines, but it can affect how we think or feel about the bigger picture. Anyway, metaphysics isn't ethics, and some people don't see a use for philosophy beyond ethics. That's their prerogative.

Plenty of realists would disagree. — Aaron R

What is an example of a realist who would disagree with a rejection of the idea that the world exists in itself?

"In itself" need not denote Kant's "ding an sich", which is just his particular take on the concept. — Aaron R

No-one says it needs to denote Kant's ding an sich, but you mentioned "thing in itself", and I replied. Moreover, plenty of scholars disagree on whether Kant's take implies two worlds or two perspectives. One is invisible and assumed to exist "in itself" whereas another is assumed to be a "visible" mind-dependent version of the invisible version. Neither is plausible, and regardless of what Kant's particular take might be I see no good reason for a realist to speak of things in themselves.

Neither is plausible, and regardless of what Kant's particular take might be I see no good reason for a realist to speak of things in themselves. — jkop

How can you be a realist and not suppose there are things in themselves? What exactly are you a realist about? This is very confusing.

If I'm a metaphysical realist, I suppose the world exists independent of us, regardless of what we say, perceive or know about such a world. The world is as it is, and will continue to be long after we're gone.

If I'm a platonist, then I suppose that numbers exist as they are regardless of what sort of mathematical discoveries we fail to make. They existed before our species could count, and they will persist after the universe is without life. And so on.

It matters the same reason for asking any sort of questions about existence. How do we get here, how big is the world, did it have a beginning, and so forth. Humans have this curiosity about such questions. And some of the proposed answers bother us, and are preferably avoided.

It may not affect our daily routines, but it can affect how we think or feel about the bigger picture. Anyway, metaphysics isn't ethics, and some people don't see a use for philosophy beyond ethics. That's their prerogative. — Marchesk

Because metaphysics doesn't have any direct practical import (even if the metaphysics was different - the world could be the same), you're misunderstanding what you're saying when you say you have curiosity about such questions. You can't be curious about something by considering alternatives which would change nothing if they were true. Even asking "which is the case?" doesn't make any sense.

Metaphysics are frameworks for understanding the world, which are judged by certain criteria. When the idealist critiques materialism, he's not saying that materialism as such is impossible, only that it is unwarranted - ie it makes too many assumptions, and we don't need so many gratuitous assumptions to describe reality. But for sure materialism could be the case - whatever that is supposed to mean. Materialism in itself is nothing. Absolutely nothing. Neither is idealism. These are frameworks. They are not objects. They are not things out there which can be the case or can fail to be the case. They are frameworks or lens through which you can look at the world.

You can't be curious about something by considering alternatives which would change nothing if they were true. Even asking "which is the case?" doesn't make any sense. — Agustino

I can be curious about scientific or historical findings that have no impact on my daily life, so that's simply not true. Humans can be interested in all sorts of things having nothing to do with everyday life.

They are not things out there which can be the case or can fail to be the case. They are frameworks or lens through which you can look at the world. — Agustino

That would be an anti-realist lens to look at the other frameworks with.

For a realist reality exists independently of his/her beliefs or statements about it. The idea that reality would somehow exist in itself adds nothing. It is a term invented by thinkers who seemed to have reasons to distinguish an invisible yet existing reality from its visible parts.

I can be curious about scientific or historical findings that have no impact on my daily life, so that's simply not true. Humans can be interested in all sorts of things having nothing to do with everyday life. — Marchesk

Yes yes, but those things have practical differences, that you can see in the world. The fact that dinosaurs existed or not, you can see the effects of that on the world. But what difference does it make, as Hillary Clinton would say, whether idealism or materialism is the case? Not for you, in your practical life. But for the world. What difference does it make?

You're confusing a framework, and discussion about which framework is the most elegant, the most simple, etc. with discussion about what is the case - with matters of fact. Metaphysics doesn't deal with matters of fact. When I say idealism is true, I don't mean the same thing as when I say chairs are true.

Metaphysics doesn't deal with matters of fact. When I say idealism is true, I don't mean the same thing as when I say chairs are true. — Agustino

By chairs being true, you mean chairs exist? So when you say that idealism is true, you don't mean that chairs exist because we perceive them, you mean that it's simpler to say that chairs exist when perceived as opposed to materialy, or mathematically, or what not.

The idea that reality would somehow exist in itself adds nothing. It is a term invented by thinkers who seemed to have reasons to distinguish an invisible yet existing reality from its visible parts. — jkop

Maybe so, but there have always been parts of the world invisible to us. A lot more of it has been made visible to us thanks to technology, but there is still dark matter, electrons, black holes, etc.