1) What is the significance of direct and indirect knowledge?...........................................3) What are the differences in direct and indirect knowledge compared to knowledge? — Corvus

I have direct knowledge of New York because I have been there, but only have indirect knowledge of Seattle as I have never been there.

I have direct knowledge of my perception of red, but only have indirect knowledge of the something in the world that might have caused it

Indirect knowledge signifies a belief.

I believe that the Space Needle in Seattle was originally sketched on a napkin, but I don't know it for a fact as I wasn't there at the time.
===============================================================================

2) Indirect or direct on relation to what? — Corvus

In relation to something in the world. The relation between what exists in the mind and what exists in the world.

That sounds confusing. Is it not the other way around? Are you sure you haven't put them wrong way around in the definition? What significance the word "indirect" have in the name? Why indirect? — Corvus

I don't believe so.

Suppose someone perceives the colour red. Both the Indirect and Direct Realist would agree that something in the world caused their perception.

The Direct Realist would argue that they are directly seeing the something in the world that caused their perception. They argue that the something in the world is actually red.

The Indirect realist argues that they are directly perceiving the colour red in their mind and only know about the something in the world that caused their perception indirectly through reason. They argue that the something in the world might be red, might be green, might be a wavelength of 700nm or might be something else altogether.

The Direct Realist argues that they have direct knowledge about the something in the world that caused their perception, whereas the Indirect Realist argues that their reasoning can only give them indirect knowledge about the something in the world that caused their perception.

So what is the difference between indirect realism and direct realism? From what you are saying, they sound exactly the same claims. — Corvus

As I wrote on page 2

Suppose someone perceives the colour red. Both the Indirect and Direct Realist would agree that something in the world caused their perception.

The Direct Realist says the person is directly perceiving the cause of their perceiving the colour red. The Indirect realist says that the person is only directly perceiving the colour red.

You seem to be confusing the point that I was trying to point out the fact that transcendental idealism has problem of having dualistic view of the world i.e. phenomenon and noumenon — Corvus

A dualistic view in itself is not necessarily incorrect. For example, a word is an example of dualism. On the one hand it exists as a shape and on the other hand it exists as what it is representing.

This describes Direct Realism:

When the perceiver and the world is in direct physical contact which allows the perceiver to have direct perception, sensation, and interaction with the world or objects in the world, the world presents to the perceiver as physical entity or material objects. — Corvus

This describes the Direct Realist closing their eyes and using their imagination:

When the perceiver is only thinking about the world without direct visual or material sensation or perception, the world is in the mind of the perceiver as ideas only. — Corvus

You haven't answered the key point question. What do you mean by "regardless of any cause"? Why is it relevant to the point? — Corvus

I wrote "When I perceive the colour red, I perceive the colour red regardless of any cause."

It goes back to your two previous statements:

You end up having 2x copies of every object in your perception, and wonder which one is the real object. — Corvus

Indirect realism's problem is using sense data as the medium of perception, which doesn't make sense. — Corvus

I am trying to show that this is a misrepresentation of Indirect Realism. For Indirect Realism, there is only "1x copy of every object in your perception."

This means that when an Indirect Realist perceives the colour red, they are only directly perceiving the colour red. They are only directly perceiving one thing. They are not directly perceiving two things, the colour red and the cause of their perception of the colour red.

As I wrote:

When the Indirect Realist perceives the colour red, for example, they are not perceiving a representation of the colour red, they are directly perceiving the colour red.
Anything otherwise would lead into the homunculus problem of infinite regression.
What the Indirect Realist does believe is that there is something in the world that has caused them to perceive the colour red, but it is unknowable whether this something in the world is actually red or not. The Indirect Realist reasons that it is not, but cannot know for sure.
In a sense, the colour red that is directly perceived is a representation of the unknown something in the world, which may or may not be the colour red.
There is only one object of perception for the Indirect Realist, and that is the direct perception of the colour red.

What are the ultimate reality for these folks in detail? — Corvus

Presumably the same as for the idealists and the materialists.

The point of idealism or materialism is to define what the ultimate reality is in the end. — Corvus

It sounds like a tautological statement, which doesn't convey any knowledge. — Corvus

The statement "When I perceive the colour red, I perceive the colour red" is a tautological statement.

The statement "When I perceive the colour red, I perceive the colour red regardless of any cause" is not a tautological statement.

Suppose someone perceives the colour red. Both the Indirect and Direct Realist would agree that something in the world caused their perception.

The Direct Realist says the person is directly perceiving the cause of their perceiving the colour red. The Indirect realist says that the person is only directly perceiving the colour red.

Saying "When I perceive the colour red, I perceive the colour red regardless of any cause" is distinguishing Indirect from Direct Realism.
===============================================================================

The point of idealism or materialism is to define what the ultimate reality is in the end. But IR and DR seem to just make vague statements on how they perceive via unknown causes or directly. They just end there. So what is the ultimate reality? They don't seem to be interested in it. Hence no point. — Corvus

A bold statement that neither Indirect nor Direct Realism are interested in the nature of ultimate reality.

Indirect Realism is about the limits of knowledge of ultimate reality. Direct Realists do believe that they know ultimate reality.

There would be no cases such that the cause of break is unknown in medical incidents. — Corvus

I doubt that the cause of a medical condition is always known.

Even though the broken leg has a cause, the doctor is treating the broken leg, the doctor is not treating the cause of the broken leg.

When I perceive the colour red, I perceive the colour red regardless of any cause.
===============================================================================

Not really. Their systems are not denied here. Rather, the OP is based on their systems, but seeing the world in a different way like Husserl and Merlou Ponty have done. — Corvus

You may not deny Indirect and Representational Realism, but you infer there is no point in them.

Doesn't sound it has a point in saying that something has cause but they don't know what the cause is. — Corvus

Doesn't sound it has a point in saying that something has cause but they don't know what the cause is. — Corvus

It would be like a doctor refusing to treat someone in pain with a broken leg until they knew the cause of the break.

It is a brave statement that there is no point in Indirect or Representational Realism, and philosophers such as Aristotle, John Locke, Immanuel Kant, Rene Descartes, Baruch Spinoza and Bertrand Russell were mistaken.

Any objects or world unobserved don't exist. They are imagined or believed to exist. — Corvus

Why should I believe in the existence of an object in the world that I have never observed existing?
===============================================================================

Indirect realism's problem is using sense data as the medium of perception, which doesn't make sense. — Corvus

It may be that your problem with Indirect Realism is, as you said on page 1: "You end up having 2x copies of every object in your perception, and wonder which one is the real object."

But this is not the case for the Indirect Realist. There is no medium of perception. There is just perception.

When the Indirect Realist perceives the colour red, for example, they are not perceiving a representation of the colour red, they are directly perceiving the colour red.

Anything otherwise would lead into the homunculus problem of infinite regression.

What the Indirect Realist does believe is that there is something in the world that has caused them to perceive the colour red, but it is unknowable whether this something in the world is actually red or not. The Indirect Realist reasons that it is not, but cannot know for sure.

In a sense, the colour red that is directly perceived is a representation of the unknown something in the world, which may or may not be the colour red.

There is only one object of perception for the Indirect Realist, and that is the direct perception of the colour red.

In Ideal Realism, unperceived objects such as the country of Australia or the object Eifel Tower don't exist until observed or perceived. — Corvus

I don't think that Australians will be happy to know that they don't exist because an Ideal Realist in the Kerguelen Islands has never heard of them.
===============================================================================

Ideal Realism also says that we perceive the world with experience via the bodily sense organs loaded with ideas, not direct. — Corvus

This sounds like the existing term "Indirect Realism" (Wikipedia - Direct and indirect realism)

I would brand this way of seeing the world and perception as Ideal Realism — Corvus

"Ideal Realism" as described sounds like the existing term "Direct Realism" (Wikipedia - Direct and indirect realism)

Even the Direct Realist can dream and imagine.

It's actually quite easy if you follow my disclaimer since understanding of such a world does not require the understander to lack a mind. It just requires the world under consideration to lack the mind. — noAxioms

We agree that there is the domain of the mind and the domain of a mind-independent world.

The problem remains that your disclaimer requires the mind to be able to understand something that we agree by defintion is independent of the mind, ie, to understand existence in a mind-independent world.

This is the same problem of how is it possible to know the unknown.

Your disclaimer makes the OP logically impossible to answer.

Disclaimer: I am not talking about ideals or the mental abstraction of Santa or anything else..........................Such an argument requires an epistemological/empirical definition of existence, and I am attempting a discussion on a metaphysical definition. — noAxioms

If we had no perceptions, we would have nothing to reason about. But we do have perceptions. Idealism reasons that there is no mind-independent world. Indirect Realism reasons that our perceptions are only representations of any mind-independent world. Direct Realism reasons that our perceptions are a one to one correspondence with the mind-independent world.

As you say, any reasoning about E1 to E6 combining Idealism, Direct Realism and Indirect Realist would result in contradictions.

Sounds like combining them would create contradictions, not just convolution. — noAxioms

Only the Direct Realist argues that we can understand existence independent of the mind, yet this is a logical impossibility. It is logically impossible because any such understanding of a mind-independent world depends on the mind understanding something that is mind-independent.

This topic is about ontology and realism, and not about perception. — noAxioms

Our only knowledge about ontology and realism is founded on our perceptions, and our only understanding of the metaphysical depends on the epistemological/empirical.

Got it. Anything not proven (pretty much everything) doesn't count as 'knowing', so you know nothing...................................I certainly don't identify with any of those labels. — noAxioms

E1 to E6 can be interpreted from the position of Idealism, from the position of Direct Realism and from the position of Indirect Realism. Each interpretation will be different. Any interpretation of E1 to E6 that is based on a combination of Idealism, Direct Realism and Indirect Realism will become unnecessarily convoluted.

If you don't identify with either Idealism, Direct Realism or Indirect Realism, which theory of perception are you using?

My understanding of Idealism, Direct Realism and Indirect Realism agrees with an article from philosophy A level.com, but there are many articles on these three theories of perception.

This A level philosophy topic looks at 3 theories of perception that explain how we can acquire knowledge from experience, i.e. a posteriori. They are: Direct Realism, Indirect Realism and Idealism

The theories disagree over the metaphysical question of whether the external world exists (realism vs. anti-realism) and the epistemological question the way we perceive it (direct vs. indirect).

Direct realism is the view that the external world exists independently of the mind (hence, realism). And we perceive the external world directly (hence, direct)

Indirect realism is the view that the external world exists independently of the mind (hence, realism). But we perceive the external world indirectly, via sense data (hence, indirect)

Idealism is the view that there is no external world independent of minds (so it rejects realism – both direct and indirect). We perceive ideas directly.

===============================================================================

I got a quote that suggests that Meinong is perhaps using E4 as his definition of exists — noAxioms

Meinong uses the terms "exists", "subsists" and "absists".

We can divide the Universe into the domain of the mind and the domain of the mind-independent.

Objective reality in E1 can refer to both the domain of the mind and the domain of the mind-independent.

By the objective state of this universe in E4, do you mean the domain of the mind or the domain of the mind-independent?

I understand that Meinong uses "exist" to refer to the domain of the mind-independent.

The only quality of the apple I'm interested in is whether or not it exists, and which definition of exists is being used when justifying the assessment one way or another...................................almost everybody uses definition E2 when the say 'exists', but then convince themselves that some other definition must also be the case. — noAxioms

There are three theories of perception, Idealism, Direct Realism and Indirect Realism.

I don't think that either Idealism or Direct Realism are philosophically valid. Therefore, the question of the definition of "exist" must of necessity be considered from the position of Indirect Realism.

E1 The only objective reality I know about exists in my mind, although I believe that an objective reality also exists in a mind-independent world.

E2 The only things I know about exist in my mind.

E3 The only things that have predicates exist in my mind.

E4 The only objective state of this universe I know about exists in my mind, although I believe that an objective state of the universe also exists in a mind-independent world.

E5 I know the state that exists in my mind, and believe that it was caused by a prior state that existed in a mind-independent world.

E6 I know the domain that exists in my mind and believe that there is another domain that exists in a mind-independent world

This presumes an epistemic definition of cause, not a metaphysical one. — noAxioms

I see a broken window and can imagine several possible causes, but don't know the actual cause. A detective visits the scene of a crime and can imagine several possible causes, but doesn't know the actual cause.

As an Indirect Realist, I see the colour green and can imagine several possible causes, but don't know the actual cause. The Direct Realist, on seeing the colour green knows that green was the actual cause.

For the Indirect Realist, epistemology limits metaphysical knowledge. For the Direct Realist, their metaphysical knowledge is not epistemologically limited.

You claim this indirect realist knows nothing about the thing, and yet he holds a belief that it exists in this way. Isn't that irrational? Is the belief just a matter of faith then?...........................All that said, identifying as a kind of realist doesn't define what is meant by 'real'. What is real? In what way is it real (R1-R6)? Some of those definitions have empirical backing and some don't. — noAxioms

Knowledge is justified true belief. As an Indirect Realist, I believe that things exist in a mind-independent world and I can justify my belief. But as my belief may or may not be true, I cannot call it knowledge.

Yes, my belief that there are things in a mind-independent world is in a sense a matter of faith, as a religious person's belief in a god is a matter of faith, but that doesn't mean it is irrational.

On the other hand, I know my perceptions of colour, smell, taste, etc, which are not matters of either belief or faith.

I know that my perceptions are real, and believe that there are things in a mind-independent world that are also real.

Generally, "real" and "exist" are synonyms, though there is nothing to stop anyone from redefining them.

Likewise, my injury would not have occurred had any of the four causes not have happened. — noAxioms

You are proposing Overdetermination, which is philosophically problematic. A solution to the Overdetermination problem would make a good PhD thesis.

From the Wikipedia article on Overdetermination

Overdetermination occurs when a single-observed effect is determined by multiple causes, any one of which alone would be conceivably sufficient to account for ("determine") the effect.
There are many problems of overdetermination. First, overdetermination is problematic from the viewpoint of a standard counterfactual understanding of causation, according to which an event is the cause of another event if and only if the latter would not have occurred, had the former not occurred.
Second, overdetermination is problematic in that we do not know how to explain where the extra causation "comes from" and "goes". This makes overdetermination mysterious.

The question never gets answered. If EPP holds, how is EPP justified? If it doesn't hold, how do we know the horse exists? How does Meinong (somebody known to deny EPP) justify the horse as being in a different domain than the unicorn? — noAxioms

As I believe that neither Idealism nor Direct Realism are valid, the question can only be looked at from the perspective of Indirect Realism.

Q1 The EPP principle is that there cannot be properties without being attached to something existing. How is this principle justified

The Indirect Realist perceives a set of properties in the mind, such as being four legged, being maned, being hoofed, etc. The Indirect Realist believes that there is a thing-in-itself existing in a mind-independent world that has caused them to perceive this set of properties in their mind, but they know nothing about any thing-in-itself.

The Indirect Realist cannot justify the EPP principle, as although they do know that there are properties in their mind, they don't know if these properties are attached to something existing in a mind-independent world. There may be, or there may not be.

Q2 If there can be properties in the absence of something existing, how do we know that horses exist

The Indirect Realist may consistently perceive in their mind the constant conjunction of the set of properties being four legged, being maned, being hoofed, etc.

They can then attach the mental concept "horse" to this set of properties.

When the Indirect Realist is thinking about a "horse", they are thinking about a set of properties. They are not thinking about an unknown thing-in-itself that may or may not be existing in a mind independent world.

Q3 If there can be properties in the absence of something existing, how do we know that horses are in a different domain to unicorns

The Indirect Realist may consistently perceive in their mind the constant conjunction of the set of properties being four legged, being maned, being hoofed, not being horned, not only being in a book, etc. They can then attach the mental concept "horse" to this set of properties.

They may also consistently perceive in their mind the constant conjunction of the set of properties being four legged, being maned, being hoofed, being horned, only being in a book, etc. They can then attach the mental concept "unicorn" to this set of properties.

The domains of horse and unicorn are different. One domain can include the property "not only being in a book", whilst another domain can include the property "only being in a book".

That doesn't mean there's no apple. It just means that we don't know the true nature of the apple. Common referent (the fact that more than one mind can experience the object) is solid evidence that it is there in some form. You can deny the common referent, but that becomes solipsism. — noAxioms

I assume you are referring to apples in a mind-independent world rather than "apples" in the mind.

It is a logical contradiction to say that we don't know the true nature of the apple, but we do we know that the true nature of the thing-in-itself is an apple.

We perceive an "apple" in our minds. Both the Direct and Indirect Realist agree that there is a thing-in-itself in a mind-independent world that has caused us to perceive an "apple" (ignoring dreams and hallucinations).

The Direct Realist says that there is a one to one correspondence between what they perceive and the thing-in-itself, meaning that the true nature of the thing-in-itself is an apple. The Indirect Realist doesn't know the true nature of the thing-in-itself.

Regardless of the true nature of the thing-in-itself, it can be labelled as an apple, which means that the label is the common referent, not the thing-in-itself.

For example, suppose the true nature of a thing-in-itself is being green, but this thing-in-itself has been labelled pink. Suppose person A perceives the thing-in-itself as purple and person B perceives the thing-in-itself as red. Person A and person B can have a conversation about the pink object because that is its label, even if the true nature of the thing-in-itself is not pink and neither person perceives the thing-in-itself as pink.

That there is a common referent, the label pink, is not evidence about the true nature of the thing-in-itself.
===============================================================================

So you agree that there are at least four causes to my injury? — noAxioms

When walking on wet gravel looking at a coyote, you slip. Simplifying the situation, you walk on gravel and slip. What is the cause of your slipping?

Walking and not gravel - don't slip
Walking and gravel - slip
Not walking and not gravel - don't slip
Not walking and gravel - don't slip

How many causes are there to your slipping? Walking is not a cause of your slipping, as you could have been walking on asphalt. Gravel is not a cause of your slipping as you may not have been walking. Walking on gravel is the cause of your slipping.

Walking on gravel is the single cause of your slipping
===============================================================================

You talk endlessly about indirect realism and information flow, but not how any of that leads to a conclusion of the necessity of a single cause for any effect. — noAxioms

Forwards in time, a single cause has a single effect. For example, a snooker ball moves in a pre-determined way when hit by a snooker cue.

Backwards in time, a single effect has more than one possible cause. For example, knowing the positions of the snooker balls on a snooker table gives no knowledge about the positions of the snooker balls on the snooker table at a prior time.

An effect is overdetermined if it has two or more distinct, sufficient causes (Wikipedia - Overdetermination). As the Wikipedia article notes, there are many problems with
overdetermination, and PhD's have been written about the topic.

But you claim exactly that. "For the Indirect Realist, apples only exist in the mind.". Do clarify this contradiction then. — noAxioms

The Indirect Realist, being a Realist, believes that there is a mind-independent world and all our knowledge about such a mind-independent world arrives as experiences through our senses.

Because of the asymmetric flow of information in a causal chain between a thing-in-itself in a mind-independent world and the experiences in our senses, we can never know the true nature of any thing-in-itself.

For example, I could consistently experience in my senses the constant conjunction of a circular shape, a sweet taste, a silky touch, an acrid smell and an absence of sound. For convenience, this consistent set of properties could be named "apple".

My only knowledge of the concept "apple" has come from experiences in my senses, not from knowledge of things-in-themselves in a mind-independent world. I can say that the thing-in-itself is an apple, but that is not to say that in reality the thing-in-itself is an apple.
===============================================================================
Tell me why

Tell me why my example is wrong, that nothing on my list caused my injury. — noAxioms

My argument against Direct Realism is that one effect, such as a broken window, can have more than one possible causes, such as a rock, bird or window cleaner. Knowing the window is broken doesn't of itself give us knowledge as to what caused the window to break.

There is a temporal direction of flow of information in a causal chain.

In a deterministic world, there is a direct flow of information in a causal chain forwards in time. I agree that choosing to walk, a recently repaved road, a shoulder not properly filled and a coyote in a distant field all inexorably lead to your breaking your hip.

There is no direct flow of information in a causal chain backwards in time. Knowing you broke your hip doesn't of itself give us knowledge as to what caused your hip to break. There could have been more than one possible cause, such as being hit by a car, slipping on wet grass, being distracted by a coyote, etc.

In a deterministic world, there is a causal chain from your choosing to take a walk to your breaking a hip, but it is also true that there is a causal chain from the Big Bang to your breaking a hip.

In that sense, the Big Bang is as much a cause of your breaking a hip as choosing to take a walk. If it is true as you say that it is empty and tautological to identify the Big Bang as the cause, then it must also be empty and tautological to identify your choosing to walk as the cause.

However, my argument against Direct Realism is that it relies on a symmetric flow of information in a causal chain. For example, Direct Realism relies on a stranger hearing that you have broken your hip and for the stranger to thereby know that the cause of your breaking your hip was your choosing to take a walk.

Direct Realism, being invalid, means that all our knowledge comes from experiences in our senses. We can then reason about the possible causes of such experiences. As all our knowledge about existence and properties are mental abstractions, this makes it difficult to discuss existence and properties when your disclaimer prohibits discussion about mental abstractions.
===============================================================================

Yes. E2, E4, E5, E6 all have a domain. E1 is the only one that lacks it, and maybe not even then. Not sure how to classify E3, since it seems to be a self-referential domain. — noAxioms

E1 - "exists" may be defined as "is a member of all that is part of objective reality"
There is the domain of being within the mind and there is the domain of being within a mind-independent world.

E3 - "exists" may be defined as "has predicates"
A horse exists because it has the property of being four legged, being maned, being hoofed, etc. In Meinong's term "exist"
Sherlock Holmes exists because he has the properties of being a detective, being a pipe-smoker, being housed in 221B Baker Street, etc. In Meinong's term "subsists"
A round square exists because it has the property of being round and being square. In Meinong's term "absists".
There are the domains of exist, subsist and absist.

1) Don't go to a dictionary to answer definition questions from philosophy or science.2) This is a philosophical discussion, so a philosophical definition is expected, not a lay definition. — noAxioms

How is "exist" defined in philosophy. You refer to the SEP article on Existence. But the article concludes that there is no satisfactory philosophical meaning of "exist"

This entry began by noting that existence raises a number of deep and important problems in metaphysics, philosophy of language, and philosophical logic. The entry has examined some of those problems and surveyed a number of different accounts of existence. None of the theories surveyed is wholly satisfying and without cost.

I referred to the Merriam Webster Dictionary definition of "exist" as "to have real being whether material or spiritual", but you say that this is not a philosophical definition.

This leads to an impasse, where a topic is being discussed yet there is no general agreement as to what the words being used mean.
===============================================================================

1) The whole point of realism is that there is a real apple independent of mind, the actual nature of which is a matter of interpretation.2) It seems that any realist (direct or not) presumes something is real, that it exists............What does it mean to have mind independent existence?...............How much is EPP necessary to justify the stance?
3) For at least the 10th time, per the disclaimer, I am not discussing ideals.
4) I am not discussing idealism, and what you call indirect realism is what everybody else calls idealism.
5) You contradict yourself again, since you claim there is no mind-independent reality under what you call indirect realism, and in so claiming, you claim to know everything about it. — noAxioms

Idealism is about what exist in the mind and Realism is about what exists in a mind-independent world. There are Direct Realists and there are Indirect Realists. The Direct Realist, such as John Searle, knows that there is a mind-independent world and the Indirect Realist, such as Kant, believes that there is a mind-independent world. The Idealist, such as Berkeley, knows that there is no mind-independent world.

As an Indirect Realist, I don't claim that there is no mind-independent reality, but I do believe that there is a mind-independent reality.

The Direct Realist knows that there is a real apple independent of mind, whereas the Indirect Realist believes that there is something independent of the mind.

In your Disclaimer you write "I am not talking about ideals or the mental abstraction of Santa or anything else". This leads to an impossible situation, in that if we are not allowed to talk about mental abstractions, yet Santa only exists as a mental abstraction, then it becomes impossible to talk about Santa at all.

How does this relate to the EPP? The EPP principle is that something must exist in order for it to have properties. Within Realism, there is the mind and there is the mind-independent world. For the Direct Realist, apples exist in both the mind and a mind-independent world. For the Indirect Realist, apples only exist in the mind. If, as I believe, Direct Realism is not valid, then we can only consider existence and non-existence from the position of Indirect Realism. From the position of Indirect Realism, our only knowledge of existence and non-existence is as mental abstractions.
===============================================================================

1) I break my hip (an effect) because 1) I chose to take a walk that day 2) there was a recently repaved road 3) shoulder not properly filled 4) coyote in distant field...................You assert only one cause is possible. I list four (with there being more), and you don't counter it. — noAxioms

If there had not been a Big Bang, you wouldn't have broken your hip. It depends whether it is valid to say that the Big Bang was one cause of your breaking your hip?

I would agree that the cause of the snooker ball starting to move was being hit by a snooker cue, but I have more difficulty in saying that one cause of the snooker ball starting to move was the Big Bang.
===============================================================================

E6 "existential quantification", where 51 is not prime because there exists an even divisor that is neither 1 nor 51. — noAxioms

I think that Existential Quantification E6 points to an important feature of "existing", and that is the domain in which something exists.

Integers exist in the domain of numbers, even if integers don't exist in a mind-independent world. Sherlock Holmes exists in the domain of literature, even if Sherlock Holmes is non-existent in a mind-independent world.

Something can both exist and be non-existent, dependent on which domain is being referred to.

Definitions are descriptions about how certain words and terms are being used. The latter doesn't have a truth value to it. — noAxioms

EPP = existence is conceptually prior to predication. What does "exist" mean? The Merriam Webster defines "exist" as "to have real being whether material or spiritual".

I agree that a definition does not have a truth value, in that the definition is not intended to represent the world as it actually is.

But why does "exist" mean "to have real being whether material or spiritual" rather than "a woody perennial plant".

It is not possible to justify why a word means one thing rather than another apart from being asserted by either common usage or government institution.

I still maintain that definitions are unjustified assertions.
===============================================================================

That's a different question that 'do apples exist?". — noAxioms

I agree that "where do apples exist" is a different question to "do apples exist", but they are connected.

The EPP implies that non-existent things cannot have properties. Meinong argued that non-existent things can have properties. But what has causation to do with this question?

For the Indirect Realist, apples only exist in the mind. For the Direct Realist, apples exist both in the mind and a mind-independent world

For the Direct Realist, Santa doesn't exist in a mind-independent world, and can therefore be said to be non-existent. For the Indirect Realist, both apples and Santa exist in the mind, and therefore neither can be said to be non-existent.

The Direct and Indirect Realist have different attitudes about non-existence.

My argument is that the Direct Realist position towards non-existence cannot be valid, because Direct Realism itself is not a valid philosophical position, in part because of the problem with causation.

This is why causation is part of the topic about non-existent things.
===============================================================================

I break my hip (an effect) because 1) I chose to take a walk that day 2) there was a recently repaved road 3) shoulder not properly filled 4) coyote in distant field......................In all my examples, there are multiple causes, each of which is necessary for the effect. — noAxioms

Both Indirect and Direct Realism have different approaches to non-existence, but I don't believe that the Direct Realist approach is valid, partly because one effect can have more than one possible cause.

Specifically, on seeing the colour red, the Indirect Realist accepts that they may not know the cause because one effect may have more than one possible causes. For example, a migraine, a green tree with the light passing through a stained glass window or a yellow field at sunset. The Direct Realist, however, argues that they know the cause was a red colour on the belief that one effect can only have one cause.

You make my argument for me in saying that one effect, breaking a hip, can have more than one cause, such as taking a walk, a repaved road, a badly repaved road and a coyote.

Once Direct Realism has been set aside, the Indirect Realist approach to non-existence can be further investigated.
===============================================================================

Things existing only in the mind or not is idealism, a valid view but one explicitly not being considered, per the disclaimer in the OP. — noAxioms

The EPP infers that non-existent things cannot have properties. Meinong argued that non-existent things can have properties.

Everything we know about the world is because of what we experience in our senses.

There are two distinct approaches, that of the Indirect and Direct Realist. The Direct Realist believes they can know what exists in a mind-independent world, and the Indirect Realist disagrees.

I believe that the problem of causation shows that Direct Realism is not valid, meaning that there is no alternative to Indirect Realism.

Non-existence can only be investigated from the position of the Indirect Realist.

Given so many definitions, the reader probably presumes his own definition instead of yours. — noAxioms

It would be an impossible task for me to persuade everyone that "thoughts exist". All I can do is assert that "thoughts exist".

To cover myself, I could give a definition, such as because "I know about it". But this is no more than a tautology.

Definitions are really no more than unjustified assertions.
===============================================================================

I'm especially interested in how you justify that there can be no more than one effect...Also, what relevance does this quibble have to do with the topic of existence? — noAxioms

Where do apples exist? The Direct Realist says apples exist both in the mind and in a mind-independent world. The Indirect Realist says apples exist only in the mind.

I don't accept Direct Realism as it depends on one effect having only one possible cause. This is where causation comes into the topic.

Why do I think that one cause has one effect? Imagine a snooker cue hitting a snooker ball. The game of snooker depends on one cause having one effect.

Over-determination is the situation where one effect has been determined by more than one cause. (Wikipedia - Over-determination). PhD's have been written about the problem.
===============================================================================

SEP article on existence, section 1 — noAxioms

:up:
===============================================================================

I break my hip (an effect) because 1) I chose to take a walk that day 2) there was a recently repaved road 3) shoulder not properly filled 4) coyote in distant field....................It isn't a path, it's a network. I gave four causes of my hip injury which wouldn't have happened given the absence of any of them. — noAxioms

Scenario one
1) You left the house for a walk.
2) You could have walked on the road or through the field. You walked on a road.
3) You could have walked in the centre of the road or on the unfilled shoulder. You walked on the unfilled shoulder of the road.
4) You could have been looking to houses the left where there was no coyote or to the field on the right where there was a coyote. You looked to the right.

Scenario two
You left the house for a walk, slipped on wet grass and broke your hip. You could have broken your hip even if there had been no coyote.

Scenario three
Even if there had been a coyote in the field to the right, you could have looked to the houses on the left, not seen a coyote, but seen a robbery, and then broken your hip.

Why relevant to existance? Do apples exist only in the mind, as the Indirect Realist says, or both in the mind and mind-independent world, as the Direct Realist says?

There is the commonly held principle (does it have a name? "EPP" if not) that existence is conceptually prior to predication, prior to it having any property at all. — noAxioms

The EPP
The EPP states that existence is conceptually prior to predication.

1) You say that this means that there must be existence before there are properties.

2) But equally, it could be the case that there must be properties before existence.

Why do you think 1) rather than 2)?

Why do you think that the existence of x is separate to the properties that x has?

Existential Quantification
In the domain of numbers, there is something x that exists that has the properties of being an integer and of being even. This something x exists in the domain of numbers, regardless of whether numbers exist in the world or are non-existent in the world.

In the domain of literature, there is something x that exists and has the properties of being a detective, of having Mrs Hudson as a landlady and of being a pipe-smoker. This something x exists in the domain of literature, regardless of whether literature exists in the world or is non-existent in the world.

Something x that exists in a domain that is non-existent in the world could be called "subsisting".

We don't ever just perceive the color red..............Judgements involve integrating all percepts into a consistent whole experience of the world. — Harry Hindu

True, both the Indirect Realist and Direct Realist are able to successfully drive through the city centre.

It is a philosophical question. Both the Indirect and Direct Realist may perceive the colour red at a traffic light, but what exactly is the nature of the thing-in-itself in the world that is causing them to see the colour red?

This is not something the driver of the car needs to think about. All they need to know when they arrive at the traffic light is whether they perceive red, orange or green.

It may well be that the thing-in-itself is in reality a yellow leprechaun, but as long as the driver consistently perceives the colour red, they will be able to successfully navigate the world.
===============================================================================

What does a direct realist do when they say the chocolate ice cream is delicious but someone else says it is disgusting? Is the direct realist talking about the ice cream or their mental state when eating it? — Harry Hindu

Exactly. Another reason against Direct Realism and for Indirect Realism.

A raw assertion without even a definition of what sort of 'exists' is being presumed. I am looking for justified statements, not opinions. — noAxioms

True. My saying that "thoughts exist" is a raw assertion without any definition of either "thoughts" or "exist".

But considering books have been written about the nature of thoughts and existence, I think my trying to define these terms would make my post far too long.

I can only hope that the reader understands what I mean by saying that "thoughts exist".
===============================================================================

So things that are non-mythical determines what exists?............This uses an anthropocentric definition of 'mythical'....................Being nonexistent and being currently extinct are very different things. — noAxioms

I would hope that few would argue with my saying that unicorns are mythical creatures.

For Meinong, something being mythical makes it subsist.
===============================================================================

Maybe we should let them (in their copious numbers) defend the position then. — noAxioms

Yes, Direct Realists should defend their position on the Forum.
===============================================================================

Perhaps we are speaking past each other. I break my leg. That causes 1) pain, 2) doctor work 3) financial troubles 4) missed days at work 5) cancelled ski trip. — noAxioms

My assumption is that in a deterministic world one cause has one effect and one effect can have more than one possible causes.

This is the core of my argument against Direct Realism.

Your example is about one event having more than one effect, which I agree with, as it supports my argument against Direct Realism.

The question is, can breaking a leg be said to cause cancelling a ski trip. After all, there is no necessary reason to cancel a ski trip just because you broke your leg. Breaking a leg may contribute to your decision to cancel your ski trip, but it would be wrong to say that breaking your leg caused you to cancel your ski trip.

Books have been written about the meaning of "causation", including the SEP article The Metaphysics of Causation
===============================================================================

You seem to be interpreting the word 'prior' to mean 'at an earlier time', which is not at all what the principle is saying — noAxioms

You say "There is the commonly held principle (does it have a name? "EPP" if not) that existence is conceptually prior to predication, prior to it having any property at all."

One of the accepted meanings of "prior" is "at an earlier time".

Do you have a source that establishes the principle that existence is conceptually prior to predication to help me understand how the terms have been defined?

Actually, I care little about Meinong's actual views since for one he presumes a classical 'reality'. I was just interested in the implications of the denial of EPP, and all these classification details seem irrelevant to that, a derailment. — noAxioms

EPP = existence is prioir to predication.

It depends whether existence is referring to 1) the existence of the Universe prior to the predication of an apple, or 2) is referring to the existence of the apple prior to the predication of the apple.

The Universe

If 1), then the EPP is accepted, and existence is prior to the predication of an apple.

The apple

If 2), then something exists, and that something has the properties of being circular, being sweet and being green.

It cannot be that case that something exists for a period of time before its properties are attached.

It cannot be the case that there are properties not attached to something.

It must be the case that the something that exists must be contemporaneous with its properties.

Then the EPP is denied, and existence is contemporaneous with predication.

Existential Quantification

1) There is something x that exists.
2) X has the properties of being circular, being sweet, being green.

The set {being circular, being sweet, being green} may be named "being an apple"

Therefore, ∃x A (x)

There is something x that exists and x has the property A of being an apple

The property of being an apple cannot be prior to x

X cannot be prior to the property being an apple

X has the property being an apple

There is something that exists that has the property of being an apple.

Therefore, the EPP and Existential Quantification are contradictory

If a rock broke the window, the effect is not only that the window is broken but also the location of the object that broke the window. — Harry Hindu

Yes I agree. Whoever sees a broken window can use all their senses, reasoning and available evidence, such as a rock lying on the floor inside the room, to make a judgement as to what actually broke the window. Their judgement might be right or wrong. This would be the same approach for both the Direct and Indirect Realist.

You are right when you say that we do know the cause of many things

It is not the case that the indirect realist may never know the cause because we actually do get at the cause on a great many things. If we didn't we wouldn't be able to accomplish tasks with the degree of success that we do. — Harry Hindu

But this doesn't get to the difference between Direct and Indirect Realism.

Your statement that for the Direct Realist the red apple they perceive is the same red apple on the table gets to the difference between Direct and Indirect Realists.

Actually, for a direct realist there is no causal process. The red apple on the table is the same red apple they perceive - the cause and effect are one and the same with no intervening process in between. — Harry Hindu

I cannot argue with your claim that God allows us to perceive the world as it really is, and if God exists then this would be a perfectly valid explanation.

As such, I find that most direct realists seem to be religious in some way or another as their God created them in a way (with a soul) that allows them to perceive the world as it is. — Harry Hindu

However, I am looking at the problem in a secular way, and for me, it is a fact that there is a causal chain from a thing-in-itself in the world to our perception of it in the mind. It is this causal chain that makes the claims of Direct Realism invalid, that the red apple they perceive is the same red apple on the table.

It is not the case that when perceiving a colour we use all our senses, reasoning and available evidence to make a judgement as to what colour we are seeing. We don't make the judgment that we are in fact seeing the colour red.

When we perceive the colour red, no judgment is involved. We perceive the colour red.

It is true that once perceiving the colour red, we can then use all our sense, reasoning and available evidence to make a judgment as to what has led up to our seeing the colour red. We can reason that there has been a flow of information from a thing-in-itself in the world to our perception of it in our mind involving a long and complex causal series of events. We can determine that there is a temporal direction to this flow of information, in that in a deterministic world one cause has one effect whilst one effect may have more than one possible causes.

We may perceive a red apple on a table, but for whatever reason, a medical problem with our eyes, the light having passed through a stained glass window or there being a sunset, the apple on the table may in fact have been green.

The Indirect Realist accepts that information may change along any causal series of events, and would not explicitly say that because they perceive a red apple the apple in the world was red.

However, as you say, for the Direct Realist there is no causal intervening process, and the red apple they perceive is the same red apple on the table.

Both the Direct and Indirect Realist are the same in using all their senses, reasoning and evidence to try to understand the original cause of their perceptions. But they differ in that for the Direct Realist there is a one to one correspondence between what they perceive and the thing-in-itself but for the Indirect Realist, what they perceive is a representation of any thing-in-itself.

The asymmetric temporal flow along a causal series of events is an important reason why the Direct Realist's position is incorrect.

Direct Realism

Quite the naive view. Does it have significant support? — noAxioms

I would guess that half of everyone on the Forum are Direct Realists.

Some of your comments suggest that you are a Direct Realist

page 2 - 1) a brick hits me in the head. The brick does not depend on our mental abstractions, yet I know about the brick (presuming I'm not knocked out cold).
page 2 - The "brick" is a total mental abstraction. The brick isn't, and the abstraction lets us know something about the latter, but hardly all of it.
page 3 - Unlike red and pain, the brick has a potential of being a thing in itself, not just an ideal.

But other of your comments suggest that you an Indirect Realist

page 3 - I've been saying that objecthood is no more than a mental abstraction
===============================================================================

Why are not the direct realists in charge of the court system? — noAxioms

The Direct Realist knows that the thing-in-itself is red, rectangular and a brick.

But this is only possible if there can be a direct flow of information from the present to the past. From the present experiences in the senses to the past causes of such experiences. But this is logically impossible.

This is one reason what I am not a Direct Realist, but rather an Indirect Realist.

One consequence of Direct Realism would be that the Detective would know who had carried out the crime, which is clearly not the case.
===============================================================================

A cause typically has many effects — noAxioms

If a "cause" has many effects, then by definition it is not a cause. A butterfly flapping its wings in Goa is not the cause of a tornado in Florida.

Assuming we live in a Deterministic world, then everything that happens in the world is determined completely by previously existing causes. From Wikipedia - Determinism

Determinism is the philosophical view that all events in the universe, including human decisions and actions, are causally inevitable.

In a Deterministic world, which I believe we live in, by defintion, one cause only has one effect.

Meinong

How do we know that horses exist and not just subsist? — noAxioms

For Meinong, the unicorn, being mythical, makes it subsist, rather than the horse, which exists.

From the Merriam Webster

Horse = a large solid-hoofed herbivorous ungulate mammal (Equus caballus, family Equidae, the horse family) domesticated since prehistoric times and used as a beast of burden, a draft animal, or for riding
Unicorn = a mythical, usually white animal generally depicted with the body and head of a horse with long flowing mane and tail and a single often spiralled horn in the middle of the forehead

Both the horse and unicorn have similar properties, apart from the unicorn having the property of being mythical.

The unicorn is mythical because no one has seen one in the world, whereas many people have seen horses in the world.

However, the fact that no one has seen a unicorn in the world does not mean that they don't exist in the world. After all, the Coelacanth had been thought extinct for 70 million years until one was found in 1938.

Meinong's terms exist, subsist and absist are useful guidelines, though particular examples can be argued over.

yes thoughts exist. — Corvus

:up:

What objects belong to the EPP? — Corvus

The EPP (existence is prior to predication) may refer to things other than objects.

Thoughts exist in the mind. Are thoughts objects?

Rain exists in the world. Is rain an object?

I was just interested in the implications of the denial of EPP — noAxioms

Properties are predicated of something. From SEP - Properties

For example, if we say that this is a leaf and is green, we are attributing the properties leaf and green to it, and, if the predication is veridical, the thing in question exemplifies these properties.

Our only belief about things-in-themselves comes from experiences in our five senses. For example, the colour red in our vision, a silky feel to the touch, an acrid smell, a sweet taste or a grating noise. All these are properties. We can never know about the thing-in-itself that we believe has caused such experiences.

The EPP states that existence is prior to predication. However, all we can ever know are predications of the supposed thing-in-itself. We can never know about the the existence of any thing-in-itself. Therefore, it is a logical impossibility to say whether existence is prior to predication or not.

As David Hume argued, existence means no more than the bundle of properties an object has. From Wikipedia - Bundle theory

Bundle theory, originated by the 18th century Scottish philosopher David Hume, is the ontological theory about objecthood in which an object consists only of a collection (bundle) of properties, relations or tropes.

We experience properties in our mind, such as the colour red, but we can never know about the existence of the supposed thing-in-itself that may have caused these experiences. Therefore, the EPP is unknowable.

Oh, I thought it was one of the three things, and not a heirarchy where 'exist' is just a special case of the other two. This contradicts your statement just below.................. For Meinong, as I understand it, numbers are objects that subsist, rather than exist or absist. — noAxioms

For Meinong, exist, subsist and absist are part of a hierarchy. Round squares absist but cannot subsist or exist. Sherlock Holmes can absist but not exist. Horses can exist, subsist and absist.

In Meinong's domain of understanding, Sherlock Holmes doesn't exist. In my domain of understanding, Sherlock Holmes exists. The question is then raised, how can something that doesn't exist exist. But this question is conflating two different domains, understandably leading to contradiction

For Meinong to separate thoughts into exist, such as horse, subsist, such as Sherlock Holmes, and absist, such as a round square, seems quite sensible. But the fact that many attack his views makes me believe that I may not really understand what he is saying.

We directly experience some things but not others seems to show that the distinction between direct and indirect is simply one of causal complexity - how far removed the effect is from its causes, not a difference in the ontology of perception as we can experience things directly and indirectly. — Harry Hindu

There is another aspect that is critical to the difference between Indirect and Direct Realism, and that is the direction of flow of information in a causal chain.

One cause can only have one effect, in that if one knows the cause then the effect has been determined by the cause. For example, if a stone hitting a glass window causes the glass to shatter, the same stone under he same conditions hitting the same glass window will always cause the glass to shatter.

However one effect can have more than one cause, in that even if one knew the effect, it doesn't follow that that one will necessarily know the cause. For example, knowing that has a glass window has shattered is no reason why one will know what caused the glass to shatter. It could have been a bird, a stone, a window cleaner etc.

There is a temporal direction of information flow in a causal chain. The Indirect Realist accepts this fact, and accepts the fact that one effect may have several different causes. This makes it impossible to follow a causal chain backwards in time. The Direct Realist doesn't accept this fact, and believes that even though one effect may have several causes, it is possible to follow a causal chain backwards in time.

The Indirect Realist accepts that they may never know what broke the window. The Direct Realist has the position that they will always know what broke the window.
===============================================================================

Red is a property of minds. Ripeness is a property of apples — Harry Hindu

You can only know whether an apple is ripe from experiences through your senses. It may be soft to the touch, it may have a sweet smell, it may have a speckled colour, it may taste bitter and there may be a dull sound when you hit it.

There is no escaping the fact that you can only know the ripeness of an apple through your senses.

Take one of these as an example. You experience a sweet smell through your sense of smell. This is no different in kind to experiencing the colour red through your sense of vision. As red is a property of the mind and not the thing-in-itself, a sweet smell is a property of the mind and not the thing-in-itself.

Ripeness is a set of properties in the mind, not a set of properties of a thing-in-itself.
===============================================================================

What does it even mean to say something is prior to properties? — Harry Hindu

These are the questions @noAxiom wants answering.

None of it explains the difference between direct and indirect, which is what I expressed confusion about..On the surface, it seems to ask if I am a realist about mind dependent experiences..................Unlike red and pain, the brick has a potential of being a thing in itself, not just an ideal. So not so similarly.................... whether the pain of another is in the same world as you...........................To say something (apple) is red is seemingly to say that the apple (ding an sich) is experience, quite the idealistic assertion, and realism only of experience, not of actual apples. — noAxioms

From Wikipedia - Direct and indirect realism

Indirect realism is broadly equivalent to the scientific view of perception that subjects do not experience the external world as it really is, but perceive it through the lens of a conceptual framework. Conversely, direct realism postulates that conscious subjects view the world directly, treating concepts as a 1:1 correspondence.

Suppose someone sees a red, rectangular brick. Both the Indirect Realist and Direct Realist would agree that there is a thing-in-itself in a mind-independent world that is causing that person to see a red, rectangular brick (ignoring the special cases of dreams and hallucinations).

However, the Direct Realist would say that the thing-in-itself is red, rectangular and a brick, as the colour red, the shape rectangular and the object brick exist in a mind-independent world. The Indirect Realist would say that they don't know the true nature of the thing-in-itself, as all they know are their subjective experiences.

I put my hand in a fire and feel pain. As an Indirect Realist, I say that the pain only exists in my mind and not in any thing-in-itself. I look at a brick and see the colour red. As an Indirect Realist, I also say that the colour red only exists in my mind and not in any thing-in-itself.

Suppose you have the subjective experiences of pain and the colour red. Presumably you believe that pain only exists in a mind and not a mind-independent world.

What argument would a Direct Realist make to justify that the colour red exists in a mind-independent world, when their only experience of the colour red is in their mind as a subjective experience?

When I see someone in pain, are they and their pain not in this same shared world my mind exists in? — Harry Hindu

We directly see the consequence of pain, such as someone grimacing. We don't directly see the pain.

Suppose I see the colour red. If I were a Direct Realist, I think that I would say that the colour red exists in a mind-independent world. As an Indirect Realist, I say that something in the world caused me to see the colour red, but whatever that something is, there is no reason to believe that it was the colour red.

There is the commonly held principle (does it have a name? "EPP" if not) that existence is conceptually prior to predication......................Meinong rejects this principle, allowing properties to be assigned to nonexistent things such as Santa — noAxioms

For Meinong, existence is a property. For the EPP, existence is prior to properties. It seems that two senses of "exist" are being used.

Meining seems to be naming something "exist", "subsist" and "absist" rather than describing something that is "existing", "subsisting" or "absisting".

For Meinong, within the mind are intentional acts towards objects.

Sense one of exist
The name "horse" can be given to objects having the properties hoofed, a mammal and long mane. "A horse" may be defined as "hoofed, a mammal and has a long mane".

Meinong gives the name "existing" to objects of intention such as a horse. Therefore, an object of intention such as a horse may be defined as "existing" as well as having the property existing.

He also gives the name "subsist" to those objects such as Sherlock Holmes, and the name "absist" to those objects such as the round square.

Because Meinong gives the name "existing" to objects of intention such as a horse, it becomes both a property of and a definition of objects of intention such as a horse.

In this sense of "exist", exist is a property.

Sense two of exist
However, there is another sense of exist, that of the Existential Generalization, whereby Fa → ∃x (Fx). If a is F then there exists something that is F.

For example, if something is hoofed, a mammal and has a long mane, then there exists something that is hoofed, a mammal and has a long mane.

Similarly, if something is existing (sense one), then there exists (sense two) something that is existing (sense one)

In conclusion, it seems that two senses of existing are being used.