I think the simple answer is that it doesn't. You have to provide that. You build a model with a domain and predicates. You have to know what the things you're filling the domain with are and how the predicates relate. It's like you're building a little world. Truth is defined in a certain way. — frank

I am sure that truth in possible world semantics is not down to personal preference, though I am definitely no expert in modal logic.

From SEP Possible Worlds

Consequently, there was no rigorous account of what it means for a sentence in those languages to be true and, hence, no account of the critical semantic notions of validity and logical consequence to underwrite the corresponding deductive notions of theoremhood and provability. A concomitant philosophical consequence of this void in modal logic was a deep skepticism, voiced most prominently by Quine, toward any appeal to modal notions in metaphysics generally, notably, the notion of an essential property. (See Quine 1953 and 1956, and the appendix to Plantinga 1974.)

The purpose of the following two subsections is to provide a simple and largely ahistorical overview of how possible world semantics fills this void.

In my words, the article is saying that in traditional modal logic there was no rigorous account of what it meant for a sentence to be true. This led to a deep scepticism. However, this void of what it means for a sentence in modal logic to be true was filled by possible world semantics.

IE, possible world semantics do somehow give a rigorous account of what it means for a sentence in modal language to be true.

In other words, in modal logic, truth is not a personal thing, in that I think that it is true that "swans are white” whilst you may think that it is true that “swans are black”.

The section you posted from the SEP mentions the concept “true”, but does not specify “true for whom”.

For the modal operators. □X, that is, necessarily X, is true at a state if X itself is true at every state that is relevant to that state (at all accessible states).

But what is the foundation for truth in modal logic?

I think all of this is correct. — frank

Continuing the quest for truth.

The SEP article Possible Worlds writes:
1 - Modal logic, by contrast, is intensional.
2 - In an intensional logic, the truth values of some sentences are determined by something over and above their forms and the extensions of their components.

This initially makes sense.

Consider the sentence “swans are white”. The truth value of this sentence cannot be known just from the sentence itself

Consider the extension of “swan”. For example {that swan in Hyde Park, this swan on Ullswater}. Knowing what a “swan” is is impossible from a finite number of examples.

As the article writes, the truth value of the sentence “swans are white” can only be determined by something over and above the form of the sentence “swans are white” and over and above the extension of its component “swan”.

Suppose I observe something X having the properties {waterfowl, flighted, white}.

I obviously cannot know whether being white is internal (necessary) or external (contingent) to X without knowing how X has been defined, and that it has been named "swan".

Suppose a “swan” has been defined as having the properties {waterfowl, flighted, white}. Then I know I am seeing a swan, and being white is an internal, necessary property. Given this definition of “swan”, swans are necessarily white in all possible worlds

From Wikipedia Extensional and intensional Definitions
Intensional definition = gives meaning to a term by specifying necessary and sufficient conditions for when the term should be used.
Extensional definition = listing everything that falls under that definition

However, it is not necessarily the case that the same definition obtains in all possible worlds.

For example:
In possible world 5, “swan” may have been defined as {waterfowl, flighted, white}
In possible world 6, “swan” may have been defined as {waterfowl, flighted, black}

The SEP article suggests that the truth value of the sentence “all swans are white” must be determined over and above its form and over and above its extension.

From the Wikipedia article Modal Logic, ☐ P is true at a world if P is true at every accessible possible world. In other words, necessarily “swans are white” is true at a world if “swans are white” is true at every accessible possible world.

However, in modal logic, this something over and above cannot be a definition, so what could it be?

How does modal logic determine truth values?

By defining necessity as f(x) being true in all possible worlds, we have extensionality within possible worlds, but not across them. In this case, necessity is a quantifier. It's telling us how many. — frank

Does the following make sense:

In possible world 5 - a chess set = {64 squares, made of stone}
In possible world 6 - a chess set = {64 squares, made of ivory}

But some of these properties may be necessary and some may be contingent.

But chess has to be defined.
Therefore, ☐ ∃x(B(x)), where x is the subject “a chess set”, and where B is the predicate “has 64 squares”
Then, it is necessarily the case that the proposition “a chess set has 64 squares” is true.
Therefore, having 64 squares is necessary.
Therefore, the proposition “a chess set has 64 squares” is true in all possible worlds.

But this definition says nothing about material.

Therefore ◊∃x(B(x))
Then, it is possible that a chess set is made of ivory.
Therefore, being made of ivory is contingent
Therefore, being made of ivory is possibly true in some possible world.

As you say, i) defining necessity as being true in all possible worlds and where ii) necessity is a quantifier (meaning “all”).

But is it not the case that:
1 - We have intentionality across all possible worlds (because necessary meaning is an intension and the necessary meaning is the same across all possible worlds)
2 - We have extensionality within each possible world (because contingent properties are an extension and contingent properties are particular to each possible world).

Hey, how badly can we mangle it? — frank

An actual possibility, but hopefully not.

This thread is for a read through of two SEP articles on possibility and actuality. — frank

I admire your confidence in being willing to tackle 60 intricate SEP pages about a generally controversial and deeply complex topic.

Do you have any idea what "noumena" is? — ProtagoranSocratist

What does Kant in the CPR mean by noumena, transcendental object and thing in itself?

The problem of exegesis
An exegesis of Kant’s CPR is problematic because his ambiguity of language makes it often difficult to determine the exact meaning of his text. Therefore, rather than trying to directly interpret his given text, and on the assumption that his underlying ideas are sensible, it may be a better approach to first establish one’s own opinions about the subject and then confirm that your own opinions are a valid interpretation of the given text. Unfortunately, following this approach, there is the real possibility that two different valid interpretations may be discovered about the same given text. A problem with David Hume, who may be read either as an Empiricist or Rationalist.

The noumenon and thing in itself in the two world view
It is clear that our concept of a red postbox may be very different from the reality of a red postbox. For example, we perceive the colour red, yet science tells us that the postbox actually emits a wavelength of 700nm. This begins to lead into the two world view, in that there are two types of object, the object as we conceive it in our mind having the colour red, a noumenon, and the object as it really is in the external world emitting a wavelength of 700nm, a thing in itself.

Even though a wavelength of 700nm is still another concept, we can reasonably conclude that what we perceive may or may not exist in the external world. In the external world what may exist may be the colour red, may be a wavelength of 700nm or may be something else altogether, say X.

The transcendental object in the two aspect view
There is also the two aspect view, where the object as we conceive it in our mind and the object as it really is in the external world are but two aspects of the same object. For a single object, having the colour red may be thought of as a different aspect of the external reality X. In other words, we start with the premise that seeing the colour red is another aspect of the emission of the external reality X. We see the colour red. We conclude that our seeing the colour red is another aspect of the external reality X. Our conclusion that seeing the colour red is another aspect of the external reality X is a justification for our premise that seeing the colour red is another aspect of the external reality X.

This is a transcendental argument. Therefore, the object that has one aspect of having the concept of the colour red and another aspect of an external reality X may be named a transcendental object. Being a transcendental object, there is a necessary and universal connection between the colour red and the external reality X.

The background to the transcendental object
All we directly know are our thoughts (concepts, ideas, reasoning, judgements, understanding) and appearances (phenomena, sensibilities). Kant wrote his Refutation of Idealism in defense of Realism, the idea that there is an external ground for these appearances. If there is an external ground for these appearances, then these appearances are determined externally and not by any human observer of them. Therefore, these appearances must have an internal reason and internal logic that mirrors their ground. Not an internal reason and logic determined by the human observer, but an internal reason and internal logic determined by the external ground. It is up to the human observer using their own reason and logic to discover within these appearances the internal reason and internal logic that already exists. It is therefore through human reason and logic that the human has a direct pathway to an external reality. Not a direct literal pathway, but a direct metaphorical pathway, where a metaphor creates a relationship between two different entities by stating that one is the other.

My explanation
Thing in itself = an object as it exists in the external world independently of our perceptions. I can think about the concept of a thing in itself, in the same way that I can think about the concept that there are things that I don’t know. However, I can never know what a thing in itself is. It is part of the two world view.

Noumenon = an object as it exists as a concept in our mind, such as our concept of a red postbox. Our concept may or may not be the same as the thing in itself, but this is unknowable. It is part of the two world view.

Transcendental object = an object as it exists in the two aspect view. The first aspect is as a noumenon, a concept in the mind. The second aspect is as a thing in itself, the ground of appearances. As knowledge of the object is synthetic a priori, which is transcendental, such knowledge is both necessary and universal.

Stephen Pinker and others have described innate language acquisition. It's not that they have innate knowledge, what you call content, it's that they have the capacity to gather and process that content–to think in structured and organized ways. — T Clark

I agree. Another example. I cannot see the colour red when I close my eyes, but have the ability to see the colour red when there is something red present in my field of vision.

The thing that jumped out to me when I read about the critique of pure reason was that Kant identified space and time as being known a priori. These strike me as exactly the kind of structured principles I described above. Time and space are not what you call "content," they are principles that allow us to organize and process content provided by our senses. — T Clark

I agree that we are born not so much with innate knowledge but with innate ability.

Carrying this idea forward, we could say that we are not born with an innate knowledge of space and time, but have an innate ability to recognise space and time in our sensibilities. In today’s terms, we could say that my innate ability to recognise space and time is a priori, where a priori is being used in a temporal sense.

However, as I understand it, this is not how Kant uses the term a priori. Kant is not using the term a priori in a temporal sense. It is being used to describe the relationship between two events that are simultaneous, contemporaneous. The concept of a cause that is contemporaneous with its effect is called "simultaneous causation”. Stephen Mumford argues that causation is always simultaneous. Aristotle’s material cause is in a sense about simultaneity. For Kant, our pure intuitions of space and time don’t originate temporally before our particular sensibilities (observations, experiences) but originate transcendentally from the very same sensibilities that they are needed to make sense of.

For Stephen Pinker, we are born with certain innate abilities that allow us to make sense of the experiences we have today, and in this sense a priori. For Kant, the abilities we have that allow us to make sense of the experiences we have today derive in a transcendental sense from the very experiences themselves, and in this sense a priori.

Because our a priori pure intuitions of space and time have transcendentally derived from our synthetic experience of space and time, these pure intuitions are necessarily necessary and universal. This is different to Hume’s observation of regularities in our synthetic experiences which are necessarily contingent and particular.

Kant believes there is something external that is causing our observations, from which we transcendentally derive our pure intuitions of space and time, but this external something, like the thing in itself, must forever remain unknown. This external something may in fact be exactly the same as our concept of space and time, but then again, it may not. We will never know.

However, as a personal opinion, there must be a real relation between our pure intuitions of space and time and the something external and unknowable, which may or may not be the same as our pure intuitions. Because our pure intuitions have been transcendentally derived from appearances, these pure intuitions must be necessary and universal as Kant proposes, even if only metaphorically necessary and universal.

I disagree with this. Maybe we could read through the Transcendental Aesthetic together and come to agreement. Who's up for that? — frank

You may be right, my wording may not have been the best.

The concept of the transcendental is important to the CPR, and is important to Kant’s principle of synthetic a priori. The Transcendental Aesthetic is 21 pages long, from A19/B33 to B73, so would be a major project.

To my understanding, for Kant, only the synthetic a priori can give knowledge. The synthetic by itself (the intuition of sensibilities, observations, appearances, experiences) cannot give knowledge. The a priori by itself (pure intuitions of space and time, pure concepts of understanding ( the Categories), pure logic, pure reason, pure judgement) cannot give knowledge. Knowledge may only be gained when the synthetic is spontaneous with the a priori.

For example, we make an observation which we make sense of using the Categories. But in Kant’s transcendental sense, these Categories did not exist temporally prior to the observations, but spontaneously came into existence at the same time as making the observations necessarily in order to make sense of the observations. Without the Categories we could not make sense of our observations, and without our observations we could not have any categories making sense of our observations.

In a transcendental argument, a strong premise about a situation leads to a reasonable conclusion. This reasonable conclusion then becomes a valid justification for the strong premise.

Perhaps the following wording would be better:

Therefore , transcendental Idealism is the idea that a strong premise (the a priori, such as the Categories) about a situation (the synthetic, such as our sensibilities) leads to a reasonable conclusion ( knowledge). This reasonable conclusion (knowledge) then becomes a valid justification for the strong premise (the a priori, such as the Categories).

Push on PDF with text then download to your files. — T Clark

:up:

Unless I’ve misunderstood you, this is not how I understand what Kant was saying. — T Clark

What does Kant mean by “a priori”?

Reason must have content, As Kant said "thoughts without content are empty, intuitions without concepts are blind”. Reason must be about something. Pure reason, which is reason without content, is impossible. Kant’s Critique of Pure Reason is a critique of pure reason, not an acceptance of the existence of pure reason.

For Kant in the CPR, all knowledge must be synthetic a priori, meaning that there can be neither purely synthetic knowledge nor purely a priori knowledge.

5+7=12 is an example of synthetic a priori mathematical knowledge, and the syllogism that all humans are mortal, Socrates is human, therefore Socrates is mortal is an example of synthetic a priori logical knowledge.

For Kant, the conscious reasoning about content is not innate in humans at birth. Children have to mature a certain number of years before being able to consciously reason about content.

If all knowledge must be synthetic a priori, which derives from reasoning about content, and there can be neither purely a priori knowledge nor purely synthetic knowledge, then reasoning can neither be temporally before nor after content. Reasoning must be contemporaneous with its content. Synthetic refers to the content and a priori refers to the reasoning, but as reasoning is contemporaneous with its content, the term “a priori” must also be considered in an atemporal sense. Atemporal in the same sense of Aristotle’s material cause (edited) rather than Hume’s temporal causation.

Kant’s synthetic a priori uses a transcendental argument, whether a Transcendental Deduction or a Transcendental Idealism.

In the Empiricism of Hume, some concepts, such as one billiard ball hitting another causes a movement, are derived using reason temporally after particular observations. Within Empiricism, these concepts are therefore contingent and accidental to particular observations, and are the basis of modern science.

In the Rationalism of Descartes, some concepts are innate, and temporally precede particular observations. Within Rationalism, these concepts, such as “there is a God”, are therefore necessary and universal.

Kant’s principle of synthetic a priori knowledge uses a transcendental argument that is neither Empiricism nor Rationalism. Within Kant's synthetic a priori, some concepts, such as the Categories, are necessary and universal because they create the very experiences that they derive from.

For Kant, in the CPR, the term “a priori” means neither innate nor inherent, in the sense of temporally preceding something else. It is meant in a transcendental atemporal sense, in that some concepts, such as the Categories, are a priori to the very experiences that they are derived from.

In case you’re interested, here’s a link to an article by Lorenz—“Kant's Doctrine Of The A Priori In The Light Of Contemporary Biology.” — T Clark

Do you have access to a clean copy of the article. From the Internet Archive, the “full text” comes out as:

This f^^ ^
is due to hereditary dl f chir -
acteristic of the ^f^ in U* 0~
disposes ^;J ncepti onof the'apri-
must realize th ^^ destr ^tion of the
orf as an organ means
concept: something natural
tionary adaptation to the laws otu«
external world has evolved a posteriori in a
certain sense, even if in a way entirely differ-
ent from that of abstraction or deduction from
previous experience.

I agree when the paper writes “In view of the indubitable fact of evolution”. The question is, did Kant mean by “a priori” what today is meant by “a prioiri”?

Again, this is not my understanding of what a priori means. As I wrote previously, I see it as knowledge we have as part of our human nature. It’s built into us. — T Clark

Many people believe that “knowledge results from biological and neurological Darwinian evolution”, as do I. In this context, the term “a priori” has a particular meaning.

However, if we are talking about Kant, this is not what Kant meant by “a priori”. In this different context, the term “a priori” as used by Kant has a different meaning

I am certainly not a Kant scholar, but it’s my understanding that he did see a priori knowledge as coming before any sensory input. It’s part of our human nature. Konrad Lorenz claims that that knowledge results from biological and neurological Darwinian evolution. That makes a lot of sense to me. — T Clark

Today it makes sense to talk about innate knowledge in the brain built up through 3.5 to 4 billion years of evolution. However, Kant in the 18th C did not regard a priori pure intuitions of space and time and a priori concepts of the categories as innate as we would understand them today. Kant's a priori is part of his Transcendental Idealism.

Kant is not using the term “a priori” to indicate the passage of time, and is more in line with Aristotle’s material cause (edited) than Hume’s causation. In Latin, “a priori” means “from the former” and can be used in an atemporal sense about something that exists outside any considerations of time.

Therefore, the relationship between a priori pure intuitions of space and time and a priori pure concepts of the categories and the phenomenology of experiences, a person’s sensibilities, should be thought about without any regard to the passage of time.

As I wrote before: “Kant did not propose that we have knowledge prior to our sensibilities, which we then apply to our sensibilities. Kant proposed in Transcendental Idealism that a priori knowledge is that knowledge derived from our sensibilities that is necessary to make sense of these very same sensibilities.”

As an analogy, suppose you fly over an island about which you have no previous knowledge. You observe stones on the beach in the form of the letters SOS. You may have the thought that these stones rolled into that position accidentally through the forces of nature, whether the wind or waves, but find such a thought almost impossible to believe. The only sensible explanation for your observation would be the existence of a human agency, even if you have no direct knowledge of such human agency.

Your belief in the existence of a human agency doesn’t transcend your observation, but is transcendental to your observation.

Your phenomenological experience is not proof of the existence of a human agency external to your observation, but neither is Kant’s Refutation of Idealism proof of his two world view. However, it clearly shows his belief in a two world view and his determined attempt to prove two realms of existence, the phenomenal and the noumenal.

Neither the desert island analogy nor Kant's Refutation of Idealism prove the two world view, but both are strong justifications for the two world view.

As I see it, as regards Kant, the intuitions of space and time and the concepts of the categories that are needed to make sense of phenomenological experiences are determined a priori (atemporally) by the very same phenomenological experiences that they need to make sense of.

Then you lose your reason for denying the possibility of non sensible or sensible intuition as an infallible source of knowledge. I recommend you to check the Critique of Pure Reason. — Sirius

Kant's Critique of Pure Reason discusses a priori pure intuitions of time and space and a priori pure concepts of the Categories. This is knowledge, but not innate knowledge that precedes our sensibilities. This is knowledge that derives from the very sensibilities that it needs to make sense of, ie, Kant’s Transcendental Idealism.

This is why I wrote “All our knowledge comes from sensory experience”.

Kant did not propose that we have knowledge prior to our sensibilities, which we then apply to our sensibilities. Kant proposed in Transcendental Idealism that a priori knowledge is that knowledge derived from our sensibilities that is necessary to make sense of these very same sensibilities.

It's useless to tell us whether this or that is unverifiable until you tell us your criteria for verification. — Sirius

A statement has been verified if the statement is discovered to be true.

It has been asked “what is metaphysics?”. One characteristic of metaphysical questions is that they are never verified to be true. For example, does anyone know the true answer to the metaphysical question “why is there something rather than nothing” or “do we have free will” or "what is the nature of reality”. In fact, if a statement can be verified, such that the speed of light is 299,792,458 m/s, then by definition it cannot be a metaphysical statement.

Not only that, you will also have to justify it. — Sirius

It is sufficient justification that metaphysical statements are not verifiable by pointing out that no metaphysical statement has been verified to be true.

Of course, if language is a tool, then it cannot be the subject matter of any science which aims to discover truths. This was known to Aristotle. — Sirius

Science is always concerned about the tools it uses. A faulty tool will give faulty answers. For example, when studying cells, the microscopes being used are constantly being tested for optical quality, resolution, etc.

But the [neo-] positivists you are echoing actually disputed this. They regarded language as unveiling the structure of the world & mind. — Sirius

Truth cannot be found within language. Truth transcends language. It is not the case that “Paris is in France is true” but rather “Paris is in France” is true IFF Paris is in France.

The neo-positivists (aka logical positivists, logical empiricists) followed the verification principle, in that a statement can only be meaningful if either empirically verifiable or a tautology.

As regards the world, a statement such as “Paris is in France” can be empirically verified, and therefore is meaningful, but as regards the mind, a statement such as “this painting is beautiful” cannot be empirically verified, and is therefore meaningless.

For the neo-positivists, language was very limited in its ability to unveil the structure of the world and mind, as not only was it forced to reject any statement that could not be empirically verified but also was forced to reject all poetic, metaphorical and emotive language.

What is metaphysics?

One aspect is that metaphysics is not verifiable, as metaphysics is undertaken using language, and truth cannot be discovered within language. Truth transcends language.

It is not the case that i) “everything within the empirical realm is in constant state of actuality (what it is now) versus potentiality (what it could be) is true” but rather ii) “everything within the empirical realm is in constant state of actuality (what it is now) versus potentiality (what it could be)” is true IFF everything within the empirical realm is in constant state of actuality (what it is now) versus potentiality (what it could be).

As Collingwood said, absolute presuppositions are not verifiable, because, as Hume pointed out, even though all our knowledge comes from sensory experiences, we can only directly observe the regularity of events, never the cause of these regularities. Through reason and logic we hypothesise a speculative cause for these regularities, and we can only reason about our sensory observations. In the absence of any sensory observation, there would be nothing for reason to reason about.

The speculations of metaphysics are not verifiable, and can only be supported by empirical observation. In physics, it is a supposition that the speed of light is 299,792,458 m/s, and in metaphysics it is a supposition that stealing is wrong. These suppositions cannot be arrived at by reason alone. The supposition of the speed of light is supported by empirical observation of astronomical events and the supposition that stealing is wrong is supported by empirical observation of human behaviour.

As with Kant, there must be a unity between what the mind observes, empirical sensory observations, and the mind’s comprehension in what it observes, logical reasoning. Also with Aristotle, there is unity between passive intellect, receiving and processing of sensory information, and active intellect, thought and reasoning.

Reason may be used to generalise the particular. From the particular, that his stealing that woman’s bag is wrong, to the general and universal, that stealing is wrong. Reasoning about empirical observations enables generalisations about particulars. Only particulars can be empirically observed. Last year in Paris the speed of light was measured as 299,792,458 m/s. Last week in Seattle, the speed of light had the same measurement. This morning, here in Copenhagen, the speed of light also had the same measurement. That the speed of light is universally 299,792,458 m/s cannot be empirically observed. It is only through reason that particular facts in the world may be universally classified. It is not only in physics that the speed of light is 299,792,458 m/s, but also in mathematics that 1+1=2. In chemistry, water is H2O, in ethics stealing is wrong, in religion that God exists and in psychology humans have free will.

Even logic cannot be thought about in the absence of reference to facts external to the thinker. The logic of the syllogism that i) all x are y, ii) z is x, iii) therefore z is y is part of linguistic thought, and as Wittgenstein pointed out, language cannot be private. Logical thought is founded on elements such as “all”, “x” and “therefore”, elements that can only be known to the thinker within a public language, and being public only accessible through sensory empirical observations.

All knowledge is speculative, whether that of physics or metaphysics, as knowledge is contained within language, and truth transcends language. Such speculation is founded on the unity between the passive intellect, empirical sensory observations, and the active intellect, reasoning, thought and logic. The only difference is the degree of public consensus. A more general consensus is that the speed of light is 299,792,458 m/s, and a more limited consensus is that stealing is wrong. All knowledge requires a fusion of reason with observation. Yesterday’s metaphysical knowledge might be today’s physical knowledge.

Metaphysics is not physics.

For example, the speed of light is a fundamental constant in nature, and is known to be 299 792 458 m / s. Physics knows that the speed of light is constant and is universal. Physics may ask why a constant and why a universal, but in order to undertake physics, physics does not need to know the answers to these questions. Metaphysics is concerned with those questions about the nature of reality that physics does not need to know the answer to.

Metaphysics asks questions, such as why does light exist, why does it have the specific value it has, why is its speed universal throughout the Universe, what does it mean to be universal, what exactly is a space encompassing 299 792 458 metres, what exactly is a time of one second, what does the number 299 792 458 mean and how does the mind know about things such as space, time, numbers and universals.

So we can ask these metaphysical questions, such as “do universals exist”, but as FH Bradley wrote "metaphysics is the finding of bad reasons for what we believe on instinct" and as Wittgenstein wrote "most of the propositions and questions to be found in philosophical works are not false but nonsensical".

Metaphysical questions and answers only exist in language, and the truth of a proposition can never be discovered within language. It is not the case that “the apple is on the table is true” but rather “the apple is on the table” is true IFF the apple is on the table. Truth transcends language. Not only is it the case that it is logically impossible to discover the truth of a metaphysical answer within philosophical language, it is also logically impossible to know whether the metaphysical question itself is valid. As both Bradley and Wittgenstein infer, truth, including metaphysical truth, cannot be discovered within language.

If metaphysical truth cannot be discovered with philosophical language, then we need to look elsewhere for metaphysical truths.

What is metaphysics?

Metaphysics asks those questions we don’t need to know the answer to, but which we are curious to know the answer to.

All WH questions are open ended and used to gain knowledge, but some WH questions are metaphysical and some aren’t. Metaphysical questions ask questions that we don't need to know the answer to because they have no import on our ability to live our lives, but only ask out of intellectual curiosity.

1 “Where is Paris?” is not a metaphysical question, as we need to know that Paris is in France when planning a holiday.

2 “When does the train arrive?” is not a metaphysical question, as we need to know this when trying to get to work.

3 “How does a rocket get off the ground?” is not a metaphysical question, as the rocket scientist needs to know the answer.

4 “What is the time?” is not a metaphysical question, as we may need to know the correct time when catching a train, but "what is time?” is a metaphysical question, as knowing the nature of time is irrelevant to the question “what is the time?”.

5 “Who is Aristotle?” is not a metaphysical question if the answer is “Aristotle was an ancient Greek philosopher”, but is a metaphysical question if the questioner is wanting to know his underlying philosophical identity, as knowing his underlying philosophical identity is irrelevant to knowing his philosophy.

6 “Why does a rock fall to the ground?” is not a metaphysical question if the answer is “because if follows the law of nature that d = 0.5 f t²”, but it is a metaphysical question if the questioner is wanting to know “why is d = 0.5 f t²”, as knowing why d = 0.5 f t² is irrelevant to knowing that d = 0.5 f t².

As described, metaphysics is over and above the axioms of physics. Physics only needs to know that certain axioms work, whereas metaphysics wants to know why these particular axioms work. Knowing why certain axioms work is not something that Physics needs to know.

Unfortunately, the very name metaphysics contains the seeds of its own destruction. For example, the fundamentals of language can only be understood using a meta language, something external to language itself. But when this meta language uses language itself, an impossible conundrum results. Similarly, the fundamentals of (physical) concepts can only be understood using meta concepts, something external to the concepts themselves. When these meta concepts use the same concepts as the concepts being investigated, another impossible situation arises.

Daniel Dennett is a Compatibilist, where free will can coexist with determinism.

A cue hits a snooker ball. The subsequent movement of the snooker ball, left, forwards, right, is determined at the moment of impact. No free will is involved and no moral responsibility is involved.

We know that we have one euro in our hand and see a charity box. Our decision i) to put the euro in the charity box ii) not to put the euro in the charity box is made at the moment of knowing we have one euro in our hand and seeing the charity box. But we are also aware of the bigger picture which affects our decision, such as do we need the money to buy food or do we trust the charity to spend the money wisely.

In one sense we are free to put or not put the euro in the charity box, but on the other hand our decision is also determined by the bigger picture, a more complex context. Unlike a machine, we are conscious of our choice, we have intentionality about our choice. For Dennett, this consciousness of our choice, our intentionality about our choice, is how moral responsibility is introduced, thereby enabling a compatibility between the exercise of free will in a particular situation that is also in part determined by knowing the bigger picture.

We may be conscious of our choice, and may have intentionality towards our choice, but how can it be argued that this of necessity means that we have a moral responsibility for our choice? What is the relationship between making a decision and being conscious of this decision? Why should it be that being conscious of a decision makes us morally responsible for that decision? This would infer that all unconscious decisions are morally neutral. What is there about being conscious of our actions that makes us morally responsible for our actions?

What is the temporal relation between our action and our consciousness of that action?

If our consciousness of an action is subsequent to the action, and we are only morally responsible for an action when we are conscious of making that action, then this would negate any moral responsibility for our actions.

Suppose our consciousness of an action precedes the action. But in what way should being conscious of something require us to be morally responsible for that something. Generally, this is not the case. Being conscious of a sunset does not make me morally responsible for that sunset. Being conscious of a thief stealing a phone does not make me morally responsible for the theft. Why should consciousness of an act require a moral responsibility for that act?

Suppose our consciousness of our action is contemporaneous with the action. In this event, if the consciousness has not caused the action, then this consciousness cannot be responsible for the action, whether physically or morally. An apple may be green in colour and sweet to the taste, but these properties are independent of each other. The property of greenness is not responsible for the property of sweetness and vice versa. Similarly, I may be conscious of a choice, and I may act on this choice, but these facts may be independent of each other. The fact of being conscious of a choice may not require being responsible for the fact of acting on this choice.

There is a problem with Compatibilism, the idea that free will can coexist with determinism. What exactly is the temporal relationship between the consciousness of a choice required by free will and the act of a choice required by determinism?

We either have free will or we don’t. If we have free will, then we cannot reason not to have free will. If we don’t have free will, then we cannot reason to have free will. If we have free will and choose how to increase a company’s wealth, then we can also choose not to increase the company’s wealth at all.

Kant in the CPR argues his thesis (A444) that there is one causality in accordance with the laws of nature and another causality of transcendental freedom.

He argues that not all causality can be in accordance with the laws of nature. As for each physical state there must be a prior physical state causing it. It would follow that there cannot have been a beginning, which is in contradiction with our understanding.

But as we experience a unity of experience from past to present, there must be a causality within our transcendental freedom, meaning that this causality must be separate from the causality that is in accordance with the laws of nature.

However, by the same argument, for each physical state there must be a physical state following it. It would follow that there will not be an end, which is not in contradiction with our understanding.

If we are able to understand a world with no end, we should be able to understand a world with no beginning. We may live in a world of infinite time. This overcomes his thesis that not all causality can be in accordance with the laws of nature.

If Kant’s argument that not all causality can be in accordance with the laws of nature is negated, this removes the necessity of a transcendental freedom separate to the laws of nature.This takes us back to all causality being within the laws of nature.

Do we really have free will? Unfortunately, a question that can never be answered.

Suppose someone makes the decision to turn left rather than turn right. On the one hand their decision may have been determined by forces outside their control. On the other hand they may have made the decision regardless of forces outside their control using their personal free will. The insurmountable problem remains that it is impossible for anyone to know, either the person themselves or an outside observer, whether that decision had been determined or freely made. And if that is the case, that it is impossible to know whether a person's decisions are determined or freely made, the existence or not of free will remain a topic with no possibility of resolution.

If Determinism is the case, the decision has been determined prior to the moment of action, and if free will is the case, the decision is made at the moment of action. We can see a cue approaching a snooker ball, and it makes sense that the moving cue causes the snooker ball to move, But the snooker ball does not move because the cue is approaching the snooker ball, it moves because of the moment of contact between cue and snooker ball. For both free will and determinism, it is within an instantaneous moment in time that the future is determined.

As we can never know what is happening within the mind at an instant in time, knowing a physical state of affairs at an instant in time gives us no information as to how that physical system will change with time. Knowing what is tells us nothing about what will be, whether this is about the mind or a physical state of affairs. And if we cannot know what will be, it logically follows that we are also unable to know the cause of what will be, meaning that we are unable to know whether the cause of what will be has been free will or prior determination.

Because of this problem with our fundamental inability to know what is happening within a moment in time, we have a fundamental inability to know whether an action is that of free will or prior determination. Free will is a problem beyond any conceivable solution.

A mental event is the subjective experience we are all familiar with. If the content of a mental event is different, then we have a different experience, so the content of a mental event determines which kind of experience one has. — MoK

A thought is a mental event, such as the thought of an apple.

But in your statement, can equally replace "content" by "form".

If the form of a mental event is different, then we have a different experience, so the form of a mental event determines which kind of experience one has.

It still needs to be shown why a thought needs both form and content, when form seems sufficient, in that the form "is" the content.

We first have to notice that each mental event has a certain content. — MoK

Not necessarily.

Unless each mental event "is" its content. The content "is" the form.

The Universe is built on fundamental particles which have no parts, yet things still happen.

The property is a (sometimes confusion) way of grouping this potency and actuality. — Count Timothy von Icarus

In scientific terms:

Suppose a boulder has a mass of 100kg.

When the boulder interacts with Earth's gravity, there is a force of 981 N pulling it towards the Earth. When the boulder interacts with Pluto's gravity, there is a force of 62 N pulling it towards Pluto. If the boulder was in outer space and not in a gravitational field, there would be no force on it.

The boulder has an "actuality" of 100kg regardless of any interaction.

The property of the heaviness of the boulder can vary between being heavy, being light or being weightless dependent upon location, but where this property is relative to a human on Earth.

The boulder's "potency" of 981 N is a function of its 100kg "actuality" and is "actualised" in an interaction with a gravitational field of 9.81 m/s sq.

The heaviness of the boulder (where heaviness is a property) is a function of its "actuality" (100kg) and the particular gravitational field it is interacting with relative to Earth's gravitational field.

The apple seems to be potentially red even when this event meeting is not occuring. — Count Timothy von Icarus

The apple appears red, because when hit by sunlight, the apple absorbs all colours except red, which is then reflected to our eyes.

A mirror reflects red light, but we don't say the mirror has the property of being red.

An apple also reflects red light. It is curious that we say an apple has the property of being red, yet we don't say a mirror has the property of being red.

I wonder at what stage in the process of this post's creation you found it appropriate to research the exact years of birth and death for each philosopher? — bongo fury

At the stage of making my point absolutely clear that for at least 400 years Western philosophy has not been built on a substance paradigm to the exclusion of a process paradigm.

Classical philosophy, like our everyday language, is built on the substance paradigm. — Astorre

Since the 17th C, with Indirect Realism, I don't think that philosophy has been built on the substance rather than process paradigm. Our language certainly isn't, as Wittgenstein's Language Games illustrates.

Indirect Realism asserts that we don't perceive the world directly but rather though representations in our minds

For example, René Descartes (1596–1650) argued that we perceive the external world through ideas or representations in the mind, not directly. John Locke (1632-1704) developed this idea. George Berkeley (1685-1753) argued that our perceptions are ideas in the mind and not physical entities. Immanuel Kant (1724-1804) emphasized the role of the mind in shaping our understanding of reality.

We can go back even further to Plato's Theory of Forms, in that we don't directly perceive substances in the world, but are only able to process shadows in our minds.

I don't think it is true to say that Classical philosophy is built on the substance paradigm.

As I have already mentioned, the modus is what is contained in the hammer itself.......................So we come to the fact that when we call something something, we don't necessarily need to know all its boundaries, but they must exist somewhere, and once we know them all, we may call it something else....................Therefore, the modus is again a construct of the mind, rather than something that actually exists., — Astorre

I agree, in that I have the concept of Poland even though I have only visited four of its towns. My concept of Poland is necessarily bounded by my personal experiences, and I infer my concept of Poland is only a pale shadow of its true reality.

However you distinguish between the "modality" of something, objective and inaccessible, and its properties, dynamic and contextual.

I have the concept of a hammer in my mind. My belief is that objects such as hammers don't exist in the world, but what does exist are fundamental particles and forces.

In my terms, the "modus" of the hammer are fundamental particles and forces, which are objective and inaccessible, enable Realism, and do exist in a mind-independent world.

These fundamental particles and forces are the indirect but real cause of my concept of hammerness.

I can explain this property of hammerness as a set of events in which a hammer participates, such as hitting in a nail, hitting a rock, being an art object, being a weapon. A property may be understood by its extension.

The property of hammerness = {hitting in a nail, hitting a rock, being an art object, being a weapon}.

These events are dynamic and exist within a context, in that a hammer in the context of carpentry is a tool for hitting in nails and in the context of war is a weapon. The Context Principle has played an important role since Frege's 1884 Grundlagen der Arithmetik.

As you say "Even though we know that the hammer is unknowable, we can still use it to drive nails, right?".

All we need to know is appearance not the cause of such appearances. All we need to know are the properties of the hammer, not any hypothetical modus of the hammer.

We drive along a road and stop when we see a red light. The fact that colours don't exist in the world but only in our minds as concepts has no bearing on the fact that we stop when we see a red light. In our daily lives we are only interested in the properties of an object, such as the property of redness. We have no practical interest in any hypothetical modus of an object (though we may have a philosophical interest).

By Occam's Razor, there is no reason why we cannot remove the concept of modus altogether, as it serves no purpose. As you say "My fascination with the processual approach to ontology is a kind of response to speculative ontology (object-oriented ontology and so on). "

My modus of the hammer are fundamental particles and forces that I believe do exist in a mind-independent world (accepting that even fundamental particles and forces are concepts).

But is what you mean by modus different to this?

What I Propose:
The modality (or the name can be changed to your liking) of a hammer is its "shadowy depth" (like Harman's), objective and inaccessible in isolation. — Astorre

An object in the world such as a rock has an almost infinite number of possible relations. As you say "properties infinitely vary in processes". For example, hitting another rock, hitting a bird, hitting a molecule of air, hitting a different molecule of air, being used by a person as a hammer, being used as a person as a paperweight, being used by a person as an art object, etc.

As you say, "as a property emerges as an event-dynamic and contextual", which cannot be argued against.

But you also say "The modality..............of a hammer is its "shadowy depth"..........objective and inaccessible in isolation"

If the modality of an object can only emerge within dynamic contexts, and there are an almost infinite number of possible dynamic contexts, this makes the modality of an object unknowable.

If the modality of an object is unknowable, then we cannot even talk about an object having a modality.

Then modality is an unknown unknown.

Because we don't learn to associate the word with one wavelength. We associate it with experiences, but those experiences reflect both physiological predisposition and cultural conditioning. Right? — frank

That's how I see it.

We are physiologically predisposed to see a family resemblance in the wavelengths from 625 to 750nm.

We are then culturally conditioned to call this family resemblance "red".

I think we just learn to associate a certain word with a certain range of visual experiences? — frank

Let the property of redness = {postbox, Northern Cardinal, sunset}

Suppose we are told to find another object, object X, that has the same property of redness and include it in an enlarged set.

All these objects emit different wavelengths.

How do we learn that object X has the same redness as a postbox, Northern Cardinal and sunset when it will be emitting a different wavelength.

Yea, but the OP wasn't saying that the set of red things is a definition of red. It was saying the set is redness because it has all the instantiations if it. — frank

Yes, for the OP:
Property redness = {postbox, Northern Cardinal, sunset}

Nelson Goodman proposed that "red" doesn't name a universal redness, but just applies to an object:
Red = {postbox, Northern Cardinal, sunset}

But it seems that the same problem applies to both. We understand the LHS by the elements in the RHS, but the elements in the RHS are determined by the LHS.

Bertrand Russell's Type Theory does not seem to negate this circularity.

One solution is the brain's ability to find family resemblances in different objects. Necessarily a meta-linguistic solution (Wittgenstein, Philosophical Investigations)

Are there other solutions to avoiding this circularity?

I think you mentioned the choice: extension/intension? I suppose the latter is a proposed solution to: "we must know the set of red things before we can include an element in the set?" — bongo fury

My solution is that it is a feature of the brain that a person can discover family resemblances in different things. For example, a postbox and Northern Cardinal share a family resemblance, and this particular family resemblance has been named "red"
https://thephilosophyforum.com/discussion/comment/1010119

Which isn't a problem (requiring a solution) in natural language. Usage there is guided by exemplification. See Goodman's Languages of Art which cashes in on the theoretical economy of analysing properties (or sets) away as predicates. — bongo fury

Suppose a person sees a postbox and a Northern Cardinal. Goodman says "red" doesn't name a universal redness, but just applies to an object. In ordinary language, I can understand a person applying the word "red" to a postbox emitting a wavelength of 650nm, but how do they know to apply the same word to a different object, a Northern Cardinal, emitting a different wavelength of 700nm?

In formalised languages, sure. The circularity is famous since Russell B. — bongo fury

In formal language, Russell's problem of sets of all sets that do not contain themselves can be formally resolved, such as by using the axiomatic Zermelo-Fraenkel set theory.

But the same problem remains. In the set of red objects R = {postbox, Northern Cardinal}, we understand red by the elements in its set, but we must know that an element is red before putting it in the set.

"Being an instance of redness" seems to be a property of all instances of redness, yet it seems to be a different property than redness itself. — litewave

"Being an instance of redness" is not a property.

"Being an instance of redness" is referring to a particular instance, which is a single concrete thing, as in "the first instance of seeing a Northern Cardinal in the wild".

The Northern Cardinal may be red in colour, but "being an instance of redness" is referring to the instance not the colour.

"Being an instance of redness" is an element of the set.

The property redness = {being an instance 1 of redness, being an instance 2 of redness, being an instance 3 of redness}.

Note
Has anyone addressed the core problem of circularity. We understand the property of redness by the elements in its set, but we must know the property of redness before we can include an element in the set?

This is an intensional definition of a set, a definition by specifying a common property of the set's elements. An extensional definition of a set would be a definition by listing all the particular elements. — litewave

Also:
Extensional definition of Ship = {ferry, tankers, icebreakers}
Intensional definition of Ship = {large boat, travels on water}
===============================================================================

What about these two: the property of redness, and the property of being an instance of redness (or the property of having the property of redness). Both properties seem to be instantiated in all instances of redness, so the instances form one and the same set. — litewave

A common example of coextensive properties

The property of "having a heart" = {human, dog, cat}
The property of "having a kidney" = {human, dog, cat}

True, a heart is a distinct thing to a kidney.

However, the above example is invalid, as a human can exist using an external dialysis machines. With medical progress, hearts and kidneys are no longer necessary to what makes a human.

Is "being an instance of redness" referring to one thing

Taken at face value, an instance is one particular thing. This infers that "being an instance of redness" is also one particular thing, meaning that it cannot be a property.

Therefore, the expression "the property of being an instance of redness" is not a valid expression.

Is "being an instance of redness" referring to several things

However, if "being an instance of redness" is referring to several things, as in "being an exemplification of redness", then it means the same as "redness".

"Being an instance of redness" and "redness" are then not distinct as a heart and kidney are distinct, meaning that "the property of redness" and "the property of being an instance of redness" is not an example of coextensive properties.

There may not be examples of genuinely different coextensive properties, meaning that it doesn't prevent us from associating a property with a set.

But now it seems that there are genuinely different coextensive properties, which would dash the hope of identifying properties with sets. — litewave

We learn the concept of an abstract property, such as redness, by discovering a family resemblance between a set of concrete objects in the world, such as a car, flower, cherry, sunset.

This set of concrete objects, being an abstract concept, is distinct from its concrete objects. In other words, the set is not contained within itself.

So it makes sense to identify properties with sets.

Are there really genuinely different coextensive properties?

Redness, then, is not inside the apple. It is born from the interplay of all three participants. — Astorre

Thing A is predisposed to emit a wavelength of 550nm, and an observer perceives colour X. Thing B is predisposed to emit a wavelength of 630nm, and the same observer perceives colour Y. Thing C is predisposed to emit a wavelength of 700nm, and the same observer perceives colour Z.

Although the observer perceives the colours X, Y and Z as different (there can be different shades of the same colour), the observer also perceives a family resemblance between colours Y and Z (such as the concept of redness).

If a person's intuitive grasp of a family resemblance between colours Y and Z is processual, a dynamic interaction between thing, light and observer, what is there in this dynamic interaction that causes the observer to treat colours Y and Z as being different in some kind to colour X (red rather than green)?

As an analogy, my feeling of pain when touching a hot radiator is not caused by the interaction, but is caused by my internal disposition to feeling pain when touching a hot object. An objective, existing mode of my being.

Now you are assuming a force without acceleration, a force which is counteracting gravity to create an equilibrium. — Metaphysician Undercover

Within general relativity, Einstein's Equivalence Principle shows that being at rest in a gravitational field is equivalent to being accelerated. (Wikipedia - Equivalence Principle)

I suppose one issue might be circularity. How do you know what belongs in a set? — Count Timothy von Icarus

One possible solution to the problem of circularity.

Suppose the property of redness = {red car, red building, red book}. We understand the property of redness by the elements in its set, but we must know the property of redness before we can include an element in the set.

Suppose there are many different objects of many different colours.

It is a feature of the human brain that a person can discover family resemblances in different things. We cannot explain how the brain does this, but we know that it does.

The family resemblance may be the colour red, being large in size, being angular in shape, being distant from the observer, etc.

Family resemblance is a term used by Wittgenstein on his book Philosophical Investigations 1953.

If a person does discover a family resemblance, this becomes a concept, such as the concept of redness, largeness, angularity, etc.

This concept of redness is abstract and singular, and is different in kind to the concrete instantiations in which the brain discovers family resemblances, such as red car, red building, red book, etc. The property of redness is distinct from its set of concrete instantiations.

Calling these objects a set is an acknowledgement that they are parts of a whole, they are parts of the concept of redness.

This can be formalised as redness = {red car, red building, red book}.

In other words, a red car has the property of redness.

The circularity is broken by the ability of the brain to discover family resemblances in different things.

I think we had this discussion before. In general relativity, gravity is not a force. — Metaphysician Undercover

I did not say that in general relativity gravity is a force.

I wrote: "According to general relativity, an apple on a table is subject to a force and because subject to a force is therefore accelerating, actively accelerating."

I am saying that the apple remains on the table because the table is exerting an upward force that stops the apple from falling

Even in general relativity there are forces.