It's the world that quantum field theory describes. — Michael

Ok. I don't understand what it is "external" to, but let it pass.

If so then either a) cups can be described by quantum field theory, or b) cups aren't objects in that external world. — Michael

So it seems you now have two worlds, one described by quantum, the other by everyday language:

Quantum field theory describes the external world, everyday languages describes a non-external world. — Michael

I don't think we should be happy with that. Seems to me better to say that we have two ways of talking about the exact same world. Multiple ways of using language, to talk in different ways about the same thing.

You haven't defined "external world" or "realism" in your question. — Michael

I hope I made it clear that given that the terms are undefined in the PhilPapers survey, continuity mitigated against my offering a definition. I presumed folk would use whatever definition suited their purposes.

But cheers - thanks for your response.

Multiple ways of using language, to talk in different ways about the same thing. — Banno

That’s where I disagree. Quantum field theory doesn’t talk about cups or cupboards or King Charles III, but our everyday language does. Therefore it’s not a case of multiple languages being used to talk about the same thing but multiple languages being used to talk about different things.

Ok. I don't understand what it is "external" to, but let it pass. — Banno

Then how do you distinguish realism from idealism? Surely “external material world” means something to you for you to make sense of being one or the other?

Then how do you distinguish realism from idealism? — Michael

Roughly, realism holds that some things are as they are, without regard to their relation to us, while idealism holds that things are otherwise; that they are as they are only in relation to us, or some mind of some sort - the details are sketchy.

I don't see that phrasing this in terms of "internal" and "external" helps much. It's got something to do with the world being internal to the mind, I suppose, but what and how...

multiple languages being used to talk about different things — Michael

I took you to be claiming that the cup was actually quantum in some way, from this:

...there is an external world but that it is properly described by something like quantum field theory and not by our everyday talk of cups and chairs — Michael

...it seemed that you thought we had a choice between describing the cup in everyday terms and describing it in quantum terms, but that quantum terms were "proper". Presumably the quantum stuff is not irrelevant nor incommensurate with the everyday stuff - as evidenced by the device on which you are reading this.

Roughly, realism holds that some things are as they are, without regard to their relation to us, while idealism holds that things are otherwise; that they are as they are only in relation to us, or some mind of some sort - the details are sketchy.

I don't see that phrasing this in terms of "internal" and "external" helps much. It's got something to do with the world being internal to the mind, I suppose, but what and how... — Banno

I think of idealism as simply being a substance monism, contrasted primarily with materialism and substance/property dualism. I don't think that "things being as they are", or truth-bivalence, depends on either materialism or substance/property dualism being true, and so isn't excluded by idealism being true.

As an example, consider the square root of 2. I don't think the answer is mind-dependent. The square root of 2 does not depend on what I think or you think or anyone else thinks. But it also isn't matter-dependent. The square root of 2 does not depend on the existence of stars or planets or electrons or gravity or even space itself. Mathematical truths are bivalent, but do not depend on materialism or substance/property dualism, and so are not excluded by idealism. Even if everything that exists is fundamentally mental in nature, there is a truth to the square root of 2 and this truth is independent of all the minds that exist. Just as if everything that exists is fundamentally physical in nature, there is a truth to the square root of 2 and this truth is independent of all the matter that exists.

As I mentioned before, there's a distinction between truth and ontology. Counterfactuals and predictions can be true even though their truth has nothing to do with anything that actually exists.

In terms of "internal" and "external", there are a few ways of considering it. If substance/property dualism is true then the "external" world is the material stuff, and the "internal" world is the immaterial stuff. If idealism is true then everything is "internal" and nothing is "external". If materialism is true then the "internal" world is the matter that constitutes our minds and the "external" world is everything else.

I took you to be claiming that the cup was actually quantum in some way, from this:

...it seemed that you thought we had a choice between describing the cup in everyday terms and describing it in quantum terms, but that quantum terms were "proper". — Banno

No, I’m just making this argument:

Objects in the external world are correctly described by quantum fields.
Cups aren't correctly described by quantum fields.
Therefore, cups aren't objects in the external world.

As an analogy, countries are not reducible to landmass. A realist might argue that landmass would continue to exist even if all humans were to die, but they might accept that countries wouldn't continue to exist if all humans were to die. And this isn't simply the trivial fact that nothing would be called a country (as nothing would be called landmass either). It is the more meaningful understanding that being a country is something that only obtains within the context of human perspective and social practices. In the absence of such a context, countries do not exist.

I think that the same logic applies to being landmass, and being a cup, and being red. These predicates only obtain within the context of human perspective and social practices. In the absence of such a context, landmass, cups, and the colour red do not exist. But the things described by something like quantum field theory do continue to exist even if all humans were to die.

So I would say that I'm a (property) dualist who believes in an external material world, and perhaps also a scientific realist, but not a metaphysical realist.

…….there is a truth to the square root of 2 and this truth is independent of all the minds that exist. — Michael

……there is a truth to the square root of 2 and this truth is independent of all the matter that exists. — Michael

What else is there?

What else is there? — Mww

Probably nothing. The mistake is in thinking that a statement's truth depends on the existence of something.

Imagine that just two things exist; a red ball and a blue ball. The statement "a red ball exists" is made true by the existence of a red ball, and the statement "a blue ball exists" is made true by the existence of a blue ball. But there are many other true statements, e.g. "a yellow ball does not exist". This statement isn't made true by the existence of the red ball or by the existence of the blue ball; rather it's made true by the non-existence of a yellow ball.

Similar situations occur with predictions (if we reject eternalism) and counterfactuals. Statements like "it will rain tomorrow" and "I would have been a father by now had I married at 18" are not made true by anything that exists. The future doesn't exist, but statements about the future can be true. Counterfactual scenarios don't exist, but counterfactual statements can be true.

And, again, the same should be evident with mathematics. The square root of 2 does not depend on the existence of space or gravity or atoms, and nor does it depend on the existence of living, thinking people. But there is a square root of 2. Its truth just has nothing to do with anything that exists.

This also explains why the claim that solipsism entails omniscience is also mistaken. Imagine that just two things exist: John's mind and Jane's mind. These minds do not interact. John is not aware of Jane and Jane is not aware of John. John and Jane each consider two statements: "only my mind exists" and "something or someone other than my mind exists". Neither John nor Jane know which of these two statements is true. Some time later, John dies. Now, only Jane's mind exists. Jane doesn't suddenly find herself knowing that only her mind exists. She still considers it possible that something or someone other than her mind exists. In fact, she might be a non-solipsist and believes that something or someone other her mind does exist. But she's wrong. Even though her mind is the only thing that exists, the truth of "only my mind exists" is independent of her beliefs.

(And as a related point, the above example shows why idealism doesn't entail solipsism. It is entirely possible that everything that exists is fundamentally mental in substance and that there are multiple minds, e.g. John and Jane. The existence of space and gravity and atoms and other material objects is not prima facie necessary for more than one thinking thing to exist.)

What else is there?
— Mww

Probably nothing. The mistake is in thinking that a statement's truth depends on the existence of something. — Michael

On the existence of something, agreed. But it does seem as though truth must depend on something, and absent mind and matter there is probably nothing, that leaves truth to be dependent on probably something. Which probably causes the critical thinker to raise one incredulous eyebrow and the average thinker to raise ‘em both.
————

….there is a square root of 2. Its truth just has nothing to do with anything that exists. — Michael

Truth, here, just indicates there is no inherent self-contradiction in the proposition, which, again, requires a mind, does it not? Whether mind or reason, even if not attributed with existence, must be something. Or maybe it’s better to say must be not nothing.
————

And as a related point, (…) idealism doesn't entail solipsism. — Michael

No, it doesn’t and shouldn’t, but typically it happens. Definition-specific apparently.

Good stuff from @Michael. I agree with the characterisation of idealism.

But it does seem as though truth must depend on something — Mww

The truth of “the square root of 4 is 2” depends on the square root of 4 being 2. But the square root of 4 being true doesn’t depend on the existence of gravity or electricity or other material object, and nor does it depend on the existence of some immaterial consciousness.

That the truth depends on something isn’t that it depends on the existence of something. Again as an example, the truth of “a yellow ball doesn’t exist” quite obviously depends on the non-existence of something.

Truth, here, just indicates there is no inherent self-contradiction in the proposition, which, again, requires a mind, does it not? — Mww

I don’t think so. There are plenty of unsolved problems in mathematics. The Reimann hypothesis is either true or false, even though it hasn’t been (dis)proven. Its truth doesn’t depend on what we believe. It doesn’t depend on what inanimate matter believes either. I suppose you could argue for mathematical realism and claim that mathematical entities exist as abstract objects, but that seems both unnecessary and fantastical.

That the truth depends on something isn’t that it depends on the existence of something. — Michael

Be that as it may, isn’t the prerogative of intelligence, insofar as it deems truth to be a valid idea, to determine what it does depends on, from whence does truth receive its justification?

I suppose you could argue for mathematical realism and claim that mathematical entities exist as abstract objects, but that seems both unnecessary and fantastical. — Michael

I’d go with fantastical, but I’d be reluctant to deny necessity. Just as for truth, there must be something by which the comprehending the appearance of natural relations, becomes possible.

Be that as it may, isn’t the prerogative of intelligence, insofar as it deems truth to be a valid idea, to determine what it does depends on, from whence does truth receive its justification? — Mww

I gave examples: "the square root of 4 is 2" being true depends on the square root of 4 being 2; "a yellow ball does not exist" being true depends on a yellow ball not existing.

Just as for truth, there must be something by which the comprehending the appearance of natural relations, becomes possible. — Mww

You seem to be suggesting that all facts are reducible to something which exists? The square root of 4 is 2 only if something exists which makes it so? A yellow ball does not exist only if something exists which makes it so? I don't see why. And in the case of the latter example, it seems even nonsensical. And why end the questioning there? Why not ask what the existence of something depends on? What does the existence of gravity depend on? What does the existence of an external material world depend on? Or does (material?) existence count as a brute fact, and the only possible brute fact?

I don't see any reason to accept that. Perhaps the existence of an external material world is a brute fact. But perhaps the non-existence of a yellow ball is also a brute fact, and doesn't in turn depend on the existence of something else. And perhaps the square root of 4 being 2 is a brute fact, and doesn't in turn depend on the existence of either physical matter or immaterial minds (or on the existence of mind- and matter-independent abstract entities).

Everything I said here seven hours ago, doesn’t relate to the content of the post it was in response to. You did some serious editing, I must say.

Anyway…..I’m not up for a do-over, so, thanks for the talk.

Maybe you can succinctly explain to me, Janus – what Wayfarer obviously can't (re: ↪180 Proof
) – the function of "transcendental idealism" in contrast to "empirical realism". — 180 Proof

I'm no Kant scholar,180, but I've got a little time this morning, so I'll give it a go. As far as I know the idea that we have access only to appearances goes back to Locke, and prior to Kant was developed by Hume and Berkeley in quite different ways. Berkeley posited that what we experience as the external world is a reality implanted in our minds by God, and Hume responded by saying that all we can know is the play of sensory phenomena and ideas, a position which leads to a particular kind of skepticism about causation and the nature of the external world. It is that skepticism which Kant sought to overcome

This observation that we have access only to appearances is open to different ways of framing it, but the basic idea is that we only have access to our personal and collective experiences and judgements. But if our experience were unconstrained by anything "outside" it, then it would be impossible to explain how we and even animals share a common world wherein it can be observed that we all (or most of us at least) respond in ways that suggest that there is a real world full of real things that is revealed to our senses. It is on account of that that Kant posits empirical realism.

However, we are able to imagine that how the world is for us is not necessarily how it is "in itself". and it might even plausibly follow, since our experience consists of "representations" that are mediated by concepts and judgements, that the world in itself cannot be the same as it is for us. We can even wonder if the world in itself could possibly be anything determinate at all.

For Kant this claim that the transcendental nature of the world in itself is inaccessible entails that it cannot be anything but an idea for us (since we cannot rationally believe after the advent of this critical realization of the role the mind plays in structuring empirical reality, that our senses reveal the mind-independent nature of the world in itself). For Kant this opens to way to faith, to the deliverances of practical reason, to belief in "freedom, immortality and God".

In answer to @Mww regarding the idea that Kant claims the objects of the empirical world must affect our senses pre-cognitively as shapes, I would ask why it could not be, in line with modern physics, that pre-cognitively the "in itself' is a field of differing energetic intensities that gives rise to the perception of entities and objects of diverse shapes and forms; that the in-itself has no "shape" as we conceive of shape.

It seems to me that we don't, and cannot, know for sure. For all we know Berkeley might have been right after all. Not to say I think he was.I like to think about different views and what they entail and imply, but I prefer to resist any tendency to adopt any of them.



As I said before, Kant's thinking, like everyone else's, is dualistic, but I see no reason to believe that he was a committed substance dualist.

I think of idealism as simply being a substance monism — Michael

Well, that's not the common view. Where did you get this from, or is it just yours?

Objects in the external world are correctly described by quantum fields.
Cups aren't correctly described by quantum fields.
Therefore, cups aren't objects in the external world. — Michael

Objects in the fribble are correctly described by quantum fields.
Cups aren't correctly described by quantum fields.
Therefore, cups aren't objects in the fribble.

But what's fribble?

But sure, this landmass counts as England in the game of politics. So what counts as internal, what counts as external? The British Isles are external, but England internal?

If substance/property dualism is true then the "external" world is the material stuff, and the "internal" world is the immaterial stuff. — Michael

So if the external is just material stuff, why use the word "external"? It adds nothing.

If idealism is true then everything is "internal" and nothing is "external". — Michael

But then if nothing is external, the difference between internal and external dissipates.

If materialism is true then the "internal" world is the matter that constitutes our minds and the "external" world is everything else. — Michael

And there being no difference between the mater of mind and the other stuff, there would again be no difference between internal and external.

So in the end I suppose we agree that the notion of internal and external is at least fraught with issues.

In terms of "internal" and "external", there are a few ways of considering it. If substance/property dualism is true then the "external" world is the material stuff, and the "internal" world is the immaterial stuff. If idealism is true then everything is "internal" and nothing is "external". If materialism is true then the "internal" world is the matter that constitutes our minds and the "external" world is everything else. — Michael

It seems that the notion of external and internal derives form the idea of things being internal or external to the body. Our bodies are experienced and understood as being in the world, but the world is not experienced as being in our bodies. Both substances and properties (apart from the substance and properties of our bodies themselves) are experienced and understood as being external to our bodies also.

If idealism were true that would not change; the experience would remain exactly the same even if the understanding changed. Unless you are speaking of solipsism, If the world were thought to be fundamentally mind our minds would still be understood to be in that universal mind, and yet that whole mind (which would include, but would not be limited to, the minds of others) would not be understood to be in my mind,

Any way, it's probably better to think in terms of dependence than in terms of internal/external if you want to arrive at coherent models of different metaphysical speculations.

But then if nothing is external, the difference between internal and external dissipates. — Banno

Maybe, they will come up with some fancy existential word like “Other” rather than “external.” At this point, just plug the fly bottle and throw it away.

It seems that the notion of external and internal derives form the idea of things being internal or external to the body. — Janus

So your liver is internal?

That just doesn't seem to be how it is being used.


Perhaps, in the end all this talk of internal and external is a poor rendering of the difference between factual and the language of our intentional attitudes towards those facts; of "The cup has a handle" against "I believe the cup has a handle".

Then materialism says there are only facts, idealism says there are only attitudes, neither is right, but at least the confusion can be set out clearly.

So your liver is internal?

That just doesn't seem to be how it is being used. — Banno

Yes the liver is internal to the body. How else do you think the notions of internal and exteranl originated, and continue to be analogously used, if not as referring to inside and outside of bodies or containers?

So idealism holds that everything is inside one's body, while realism holds that everything is outside one's body.

How odd.

So idealism holds that everything is inside one's body, while realism holds that everything is outside one's body.

How odd. — Banno

How odd that you should think I was saying that. Perhaps if you read more closely you would have noticed the " analogously used", which I have now underlined for your benefit.

Also note that I have specifically said that I don't think idealism ( apart from solipsism) holds that everything is inside anything:

If idealism were true that would not change; the experience would remain exactly the same even if the understanding changed. Unless you are speaking of solipsism, If the world were thought to be fundamentally mind our minds would still be understood to be in that universal mind, and yet that whole mind (which would include, but would not be limited to, the minds of others) would not be understood to be in my mind, — Janus

I can't see that the analogue works. "Internal", in so far as it makes any sense, is in the mind, not in the body.

The "analogy" was not meant to indicate that internal always refers to things as being inside bodies, but as being inside some "container" or other, however that might be conceived. The liver is inside the body, the brain is inside the body: is the mind inside the body? If you are one of those who hold that the mind just is the brain, or even that the mind is a function of the brain, then you would have to, out of consistency, say "yes", no?

Ok.

That does not look right, but I'll leave you to it.

What does not look right?

It seems that the notion of external and internal derives form the idea of things being internal or external to the body. — Janus

Again, if you had said " the notion of external and internal derives from the idea of things being internal or external to the mind", it might have some traction.

That seems overly esoteric and philosophically sophisticated to me. I think the notions of external and internal would have likely had a much more pedestrian origin. Like inside or outside the cave, house, or body, or bucket, or the woods, or the village and so on. But we'll likely never know exactly where the idea originated, since it was probably of pre-literate origin.

Oh, you are just after an etymology. It's just "in", from PIE "en", I think. Seems the "turn" is just comparative.

Hence my puzzling as to what is "in", when used in the context of idealism and realism.

Oh, you are just after an etymology. It's just "in", from PIE "en", I think.

Hence my puzzling as to what is "in", when used in the context of idealism and realism. — Banno

Not so much an etymology as the origin of the concepts of being inside or outside. If the idea was first expressed in Proto-Indo-European that still would leave open the question of the origin of the concepts.

I think we can make sense of inside and outside in various philosophic contexts, whether realist or idealist. That wouldn't mean that there is only one way to make sense of them, even in the context of a specific metaphysical ideology.

Well done, and more or less my take on Kant's project as well. My question, apparently, wasn't clearly stated or precisely focused, but your precis gives me an opportunity to nail it down more concretely. Consider ...

My thinking:

IF Kant is an "empirical realist",

and if "empirical" denotes how something is experienced or appears to us

and if Kant's ding-an-sich, or "in itself", denotes reality,

THEN, for the "empirical realist", appearances (i.e. "phenomena") are reality – or only aspects of reality;

THEREFORE, "for us"-"in itself" is a distinction without a difference either epistemically or onticly.

My re-question:

Where does my thinking about (the implications of) Kant's "empirical realism" go wrong? :chin: