Doubting your disbelief?

[PixyMisa]

I'm talking about gaining knowledge a posteriori, ie. by experience. The motor of our experience is what I called vision, that is, the way we perceive things.

You mean the way we interpret our perceptions?

What do you mean? What are the axioms of science as stated by yourself???

The two I repeat later on in my post.

I'm not denying this. You do add "in some sense". The question is: how far can we trust this information?

It actually doesn't matter. The only requirement (in addition to the two axioms) is that our senses bear some relation to the external world, however slight. Given the two axioms, it is impossible that they do not. So this suffices, and there is no third axiom.

Is there more to the knowledge and existence acknowledged in this way?

No; if we accept the original axioms this is not possible.

I still don't see why it is pointless. You are, again, putting human knowledge on a piedestal: "If I cannot know, then the question is pointless".

Whether any (well-formed) scientific theory is true is unknowable under all circumstances - except in the case where it has been falsified. So the only two truth values a theory can have are falsified and not yet falsified.

That's a simple consequence of the inductive nature of science.

The question, imho, remains valid if the described concept is independant. QM could very well be a valid way to describe the world. I'll go further: QM could very well be true. Independantly from you. The fact that you cannot know makes no difference whatsoever.

But I don't come into it at all; it's a question of logical principles.

What do you mean?

Oops. I rather mangled that sentence, but what I mean is what I just said a little further up.

What do you mean, cannot be justified in principle?

Um, just what I said.

Your atheism can be proven false? How?

Essentially, by presenting me with a god.

You are right. Not only do you not have to believe in it to do it, but you don't need to believe it to accept its predictions as valid. All that is needed is to look at the material evidence and admit that science works at least at this level. Surely, one can believe in science. And in this case it does become a belief system. But this is not needed. The best example would be... me! I'm a physics student and although I want to eventually conduct some research in the field, I cannot say that I hold science as true. I admit that it works on some level and that is all. Actually, the reason I am in physics is that I simply enjoy solving problems.

That's a fine reason. Perhaps the best. I like solving problems too, but I don't like solving problems in multivariable calculus, so I ended up in compuer science instead.

That I am "walking towards the truth" is pure baloney to my eyes.

Sure, I wouldn't use "truth" in that way either. Expanding human understanding is how I might put it.

It's funny, however, because despite my own convictions, I still held science as a belief system. But you are right that it does not have to be. Do you mind if I adopt your idea?

I don't think it's really mine, but you're welcome to it. I've stolen ideas from so many people (in this area, Hofstadter, Dennet and Popper most directly) that I can't tell you where it came from.

Those are not the only axioms of science, if that's what you meant.

I think they are; I could be wrong, but I am unconvinced of that.

Why?

Ah. Actually, that statement was incomplete, and it goes back to a post I wrote a couple of years back.

Naturalism (and materialism likewise) and the coherent forms of idealism are monisms. They propose a single meaning for the term exists. Materialsm says that matter is what exists. Under materialism, mind is a property or function of certain complex material systems.

Dualism posits two meanings for the term exists. Typically under dualist metaphysics we have both mind and matter.

Now, if mind and matter interacted with each other consistently, we could collapse them into a single substance that we might call stuff. Then we would be monists again, rather than dualists. So it is a necessity that any self-consistent statement of dualist metaphysics posits a universe that is inconsistent. The corollary is that any statement of dualist metaphysics that posits a self-consistent universe is itself inconsistent.

So, there are actually three possibilities presented:

(i) Dualism is monism in a funny hat.
(ii) Dualism is incoherent.
(iii) The universe doesn't follow a consistent set of laws.

Under (i), dualism ain't dualism. Under (ii), well, you don't know what to do. Under (iii), science fails.

The belief in the supernatural world is more general... perhaps not valid, but certainly more general. Of course it is in opposition with naturalism but not with science in itself.

As far as I can see, naturalism is the essence of science, so supernaturalism (which is dualist) is necessarily in opposition to science.

What were the points we initially wanted to make anyway?

Uh. I've forgotten.

 

[PixyMisa]

This is interesting. You said "if it interacts, it exist" and "if it doesn't interact, it doesn't exist". But here we come to a point where interaction is a relative concept. Existence is not. It either exist or it doesn't. Whether or not you can interact or detect it is irrelevant. As long as someone can, or as you say, as long as it can be detected in principle, it exists.

But you cannot, even in principle, violate the laws of physics. Not if you want to produce meaningful statements about the universe; and statements of existence are statements about the universe (since we define the universe as all that exists).

Now, since space-time itself is described by the Theory of Relativity, it follows that all valid statements of existence are relative.

Wrong. 'No difference to an observer outside of the light cone of the event' is not equivalent to 'no defference at all'. The fact that we exist makes no difference to some alien living outside of our light cone. But our existence is not affected by this observation. We exist independantly of what said alien might percieve.

What I'm arguing is that this is not a valid statement, since it cannot in principle be confirmed or denied.

... as seen by [insert oberver].

I'd say relative to, but yes.

If there existed no life on earth, would the earth still exist?

Yes, I would say so. The difficulty there comes not from relativity, but from quantum mechanics, and even then from interpretations rather than the direct results of the theory itself.

Talking about the limitations due to the speed of light is equivalent to assigning existence from observation. Whether we can observe it or not, whether we can interact with it or not is irrelevant to existence. As long as it interacts with something, anything, it exists.

Existence is tied up with space and time.

Let's take the fourth dimension as a line, with our "present" a point thereon. If we take a uranium atom and bop it with a neutron so that it undergoes fission, the uranium atom no longer exists; we can observe that directly. We can mark out an interval on the time-line indicating the duration of the existence of that atom.

But time is relative. The start and end points that we marked are only meaningful in our frame of reference; to another observer the atom might not yet exist, or might still exist. If we take three observers (and contravene relativity) it is quite possible to have one report that the object has never existed, another that it indeed exists, and another report that it has ceased to exist. And unless we allow that existence is relative, all three statements are equally valid.

An alternative is to ignore time entirely, in which case any object that has ever existed or will ever exist is something we can say does exist. I think this causes unwonted injury to the poor verb, though.

 

[Gertrude]

You mean the way we interpret our perceptions?

Both the way we interpret our perceptions and the way our perceptions work.

It actually doesn't matter. The only requirement (in addition to the two axioms) is that our senses bear some relation to the external world, however slight. Given the two axioms, it is impossible that they do not. So this suffices, and there is no third axiom.

The two axioms:

(A) Universe is causally closed.
(B) Universe follows consistent behaviour.

I don't quite see how the fact that "our senses bear some relation to the external world" can be derived from these two axioms...

No; if we accept the original axioms this is not possible.

Again, I don't see why.

Whether any (well-formed) scientific theory is true is unknowable under all circumstances - except in the case where it has been falsified. So the only two truth values a theory can have are falsified and not yet falsified.

That's a simple consequence of the inductive nature of science.

Sure, that is completely valid within the scientific approach. But philosophically speaking, the fact that you will never know what the answer is does not make the question any less pertinent.

But I don't come into it at all; it's a question of logical principles.

That's fine. I'll probably keep asking myself questions like this for the fun of it. In the end, I'll just admit that I don't know. And I actually don't mind not knowing.

Essentially, by presenting me with a god.

As this proves your atheism false, it will also prove theism to be true. The two go hand to hand. None is really more superior to the other.

That's a fine reason. Perhaps the best. I like solving problems too, but I don't like solving problems in multivariable calculus, so I ended up in compuer science instead.

Multivariable calculus problems, aren't they fun, eh! Actually, computer science is the one subject that has given me the most trouble so far. Well, I say 'computer science' but it's more like baby programming. That stuff is just beyond me!

Sure, I wouldn't use "truth" in that way either. Expanding human understanding is how I might put it.

I'll keep that. Thanks!

I think they are; I could be wrong, but I am unconvinced of that.

What about: experimentation is a valid way to obtain knowledge. Or: logic provides a valid interpretation of phenomenons. Actually, you sort of assume parts of these. "(B) Universe follows consistent behaviour." implies that this behaviour can be correctly observed, probably by experimentation for immediate events. "(A) Universe is causally closed" implies that causality applies. And causality is a subset of logic, no?

Ah. Actually, that statement was incomplete, and it goes back to a post I wrote a couple of years back.

Naturalism (and materialism likewise) and the coherent forms of idealism are monisms. They propose a single meaning for the term exists. Materialsm says that matter is what exists. Under materialism, mind is a property or function of certain complex material systems.

Dualism posits two meanings for the term exists. Typically under dualist metaphysics we have both mind and matter.

Now, if mind and matter interacted with each other consistently, we could collapse them into a single substance that we might call stuff. Then we would be monists again, rather than dualists. So it is a necessity that any self-consistent statement of dualist metaphysics posits a universe that is inconsistent. The corollary is that any statement of dualist metaphysics that posits a self-consistent universe is itself inconsistent.

What if mind and matter do not interact?

So, there are actually three possibilities presented:

(i) Dualism is monism in a funny hat.
(ii) Dualism is incoherent.
(iii) The universe doesn't follow a consistent set of laws.

Under (i), dualism ain't dualism. Under (ii), well, you don't know what to do. Under (iii), science fails.

Ah, Jeez, I'm slow today! From your argument, I can't distinguish between (i) and (ii). Sure if 'mind' and 'matter' interact, then we are presented with only one aspect: 'stuff'. Both (i) and (ii) apply. But if they don't interact, duality is coherent and does not interfere with a material description of the world. Science works the same and we have found a more general philosophy. None of these cases apply.

As far as I can see, naturalism is the essence of science, so supernaturalism (which is dualist) is necessarily in opposition to science.

Science is a subset of naturalism. Supernaturalism is in opposition with naturalism but not with the subset that is science. Nowhere in the axioms of science is it said that we can gain knowledge of absolutely everything. Science basically says: "Let's observe how stuff works and try to make up laws that apply." It does not say: "Everything that we observe can be described by such laws." So far it has, but it is not an axiom of science. We can try to use science to describe unexplained phenomena X, but it may forever fail. And this will not destruct the whole system. As I earlier said, science still works on some level.

Uh. I've forgotten.

Good! I feel better now.

 

[Gertrude]

But you cannot, even in principle, violate the laws of physics. Not if you want to produce meaningful statements about the universe; and statements of existence are statements about the universe (since we define the universe as all that exists).

I exist. I know that for sure! Whether some alien can or cannot interact with me means nothing. I still exist. In this sense, existence is completly objective and independant. What remains outside of our light cone, we cannot know. All we can do is assume its existence. (This is what cosmology does, by the way. It assumes that the universe is everywhere the same, ie. same density, same laws.) The other possibility, of course, is to say that you don't know. But saying that it does not exist is a little self-centered imho.

Now, since space-time itself is described by the Theory of Relativity, it follows that all valid statements of existence are relative.

Not sure I follow... This has nothing to to with the light cone, which only states that no information can travel faster than the speed of light. This was a known fact well before Einstein.

What I'm arguing is that this is not a valid statement, since it cannot in principle be confirmed or denied.

What does it matter whether you can confirm it or not? It exists or it doesn't. What you think about it is completely irrelevant. If we weren't there at all, the earth would still objectively exist, independant of our own verification.

I'd say relative to, but yes.

Excuse the french speaker.

Yes, I would say so. The difficulty there comes not from relativity, but from quantum mechanics, and even then from interpretations rather than the direct results of the theory itself.

I don't follow...

Existence is tied up with space and time.

Let's take the fourth dimension as a line, with our "present" a point thereon. If we take a uranium atom and bop it with a neutron so that it undergoes fission, the uranium atom no longer exists; we can observe that directly. We can mark out an interval on the time-line indicating the duration of the existence of that atom.

But time is relative. The start and end points that we marked are only meaningful in our frame of reference; to another observer the atom might not yet exist, or might still exist. If we take three observers (and contravene relativity) it is quite possible to have one report that the object has never existed, another that it indeed exists, and another report that it has ceased to exist. And unless we allow that existence is relative, all three statements are equally valid.

An alternative is to ignore time entirely, in which case any object that has ever existed or will ever exist is something we can say does exist. I think this causes unwonted injury to the poor verb, though.

Clocks in a reference frame appear to tic slower to an oberver in movement with respect to this reference frame. Delta-t (ie. the time between two tics) will always be smaller in the rest frame. If something exists in the rest frame (ie. the frame at rest with the object) then it exists in all moving frames. And, of course, if the event did not happen in the rest frame, then it simpy did not happen in any frame.

I don't see where relativity interferes with an independant concept of existence. Sure, the 'length of time' that it exists is different, but existence itself is maintained. Recall the first postulate of special relativity: the laws of physics are the same in all inertial frames of reference.

 

[PixyMisa]

Both the way we interpret our perceptions and the way our perceptions work.

Okay.

I don't quite see how the fact that "our senses bear some relation to the external world" can be derived from these two axioms...

Well, we are part of the world. Our senses are part of the world. They are delivering information to us. We have already assumed that the universe is causally closed and follows consistent rules, so we can discard naughty tricksy demons and the like as an explanation for sensory data.

Our senses are physical things processing physical data according to consistent laws, because (according to our axioms) there isn't anything else for them to be. So although our senses may be (are!) flawed, the data they present us always relates to some physical event.

By comparing the data our senses present to us before and after we perform certain actions, we assemble a body of inferences relating to how the world is put together. Indeed, we spend the first few years of our lives doing little else.

Some of those inferences are systematically incorrect - that's one of the great discoveries of science. Science continues the inferential process that we evolved naturally.

Again, I don't see why.

I might be confused as to your exact question. What I'm saying is that the set of knowledge obtainable in principle from the material universe is a closed set, and insofar as it is obtainable at all, it is obtainable through our senses.

Sure, that is completely valid within the scientific approach. But philosophically speaking, the fact that you will never know what the answer is does not make the question any less pertinent.

I would argue that this is exactly what it does. Many philosophers would disagree with me, and this is precisely why many philosophers are still struggling with the same problems as Plato.

As this proves your atheism false, it will also prove theism to be true. The two go hand to hand. None is really more superior to the other.

The point is that my atheism is not provable, but it is falsifiable by a single example. Theism is not falsifiable. The falsifiable statement is (from Popper) the stronger one.

Multivariable calculus problems, aren't they fun, eh! Actually, computer science is the one subject that has given me the most trouble so far. Well, I say 'computer science' but it's more like baby programming. That stuff is just beyond me!

I never liked calculus, but linear algebra and finite maths I somehow always found appealing and intuitive. I'm happy with my toys and happy there are people who do calculus for fun.

What about: experimentation is a valid way to obtain knowledge. Or: logic provides a valid interpretation of phenomenons. Actually, you sort of assume parts of these. "(B) Universe follows consistent behaviour." implies that this behaviour can be correctly observed, probably by experimentation for immediate events. "(A) Universe is causally closed" implies that causality applies. And causality is a subset of logic, no?

That's the way it seems to me. If you assume those two things, all the other stuff falls out of them.

What if mind and matter do not interact?

Then you have two separate universes. I suppose that is a fourth case.

Ah, Jeez, I'm slow today! From your argument, I can't distinguish between (i) and (ii).

Well, and example of (i) might be:

There are two fundamental natures of existence: Mind and matter. Mind and matter both follow consistent laws in their interactions with themselves. They also follow consistent laws when they interact with each other.

That collapses to monism.

A type (ii) would be Cartesian dualism:

There are two fundamental natures of existence: Mind and matter. Mind and matter both follow consistent laws in their interactions with themselves. They never interact with each other, being entirely distinct and separate. The pineal gland is the mediator between mind and matter.

Saying that they two realities don't interact, and then saying they do interact, makes the statement itself contradictory.

Sure if 'mind' and 'matter' interact, then we are presented with only one aspect: 'stuff'. Both (i) and (ii) apply. But if they don't interact, duality is coherent and does not interfere with a material description of the world. Science works the same and we have found a more general philosophy. None of these cases apply.

If mind is a real and separate thing and doesn't interact with matter, then our minds can't study the material universe at all!

Science is a subset of naturalism.

Yes.

Supernaturalism is in opposition with naturalism but not with the subset that is science. Nowhere in the axioms of science is it said that we can gain knowledge of absolutely everything.

What it says is that everything observable is explicable in terms of something else, also observable. That's what falls out of the two axioms. Supernaturalism breaks one or both of the axioms.

Science basically says: "Let's observe how stuff works and try to make up laws that apply." It does not say: "Everything that we observe can be described by such laws." So far it has, but it is not an axiom of science. We can try to use science to describe unexplained phenomena X, but it may forever fail. And this will not destruct the whole system. As I earlier said, science still works on some level.

That is partly true. Depending on the nature and degree of the supernatural intervention, science may still work in a practical sense, though it fails as a philosophy of knowledge.

 

[PixyMisa]

I don't follow...

Don't worry about it. I'm talking about the "observer" problem in various interpretations of QM.

Clocks in a reference frame appear to tic slower to an oberver in movement with respect to this reference frame. Delta-t (ie. the time between two tics) will always be smaller in the rest frame. If something exists in the rest frame (ie. the frame at rest with the object) then it exists in all moving frames.

That's true, but not what I'm getting at.

I don't see where relativity interferes with an independant concept of existence. Sure, the 'length of time' that it exists is different, but existence itself is maintained. Recall the first postulate of special relativity: the laws of physics are the same in all inertial frames of reference.

The problem is that unless you take relativity into account, you can have multiple contradictory statements about the existence of the same object, all of which are equally valid. To assert that existence is independent of relativity is to assert a universal preferred frame of reference.

 

[PixyMisa]

Or... So it seems to me.

As far as I can see, for to exist to exist as a meaningful verb in relation to the material universe, it must take relativity into account.

As I said earlier, the alternative is to abandon time (specifically, epoch) as an attribute of existence, so it would be valid to say that dinosaurs and trilobites and the burned-out white dwarf husk of the Sun all exist. That's not wrong, and it avoids the relativity issues, but it changes the meaning of the word sharply from its common usage.

 

[Gertrude]

Well, we are part of the world. Our senses are part of the world. They are delivering information to us. We have already assumed that the universe is causally closed and follows consistent rules, so we can discard naughty tricksy demons and the like as an explanation for sensory data.

But you have not defined what the rules are exactly. Actually, nobody knows! Science tries to find out what they are. Who knows, perhaps naughty tricksy demons are part of the rules! The fact that we obtain information, strictly speaking, does not guarantee the validity of said information.

Our senses are physical things processing physical data according to consistent laws, because (according to our axioms) there isn't anything else for them to be.

Again, we have said there were rules, but not what they were. By the way, the axioms state that there are rules but certainly not that these are all there is.

So although our senses may be (are!) flawed, the data they present us always relates to some physical event.

I disagree for the sake of disagreement. I certainly won't bother to question the nature of my vision if I see a car rolling full blast towards me. But strictly speaking, the argument is fallacious for the reasons I stated.

By comparing the data our senses present to us before and after we perform certain actions, we assemble a body of inferences relating to how the world is put together. Indeed, we spend the first few years of our lives doing little else.

Absolutely. But it could be argued that our senses are useful only in a self-preservation way. Our senses are a result of evolution and are useful in finding food, communicating with other humans and detecting danger. That they are a valid tool to gain knowledge is only an assumption and must be stated as such.

Some of those inferences are systematically incorrect - that's one of the great discoveries of science. Science continues the inferential process that we evolved naturally.

Yes, it continues. But it may not make up for everything. There may be areas of knowledge that we will never know about due to our own limitations (and that of science).

I might be confused as to your exact question. What I'm saying is that the set of knowledge obtainable in principle from the material universe is a closed set, and insofar as it is obtainable at all, it is obtainable through our senses.

I agree that there is no other way for us to gain knowledge. The question concerns the validity of this knowledge.

I would argue that this is exactly what it does. Many philosophers would disagree with me, and this is precisely why many philosophers are still struggling with the same problems as Plato.

Add me to the list, then.

The point is that my atheism is not provable, but it is falsifiable by a single example. Theism is not falsifiable. The falsifiable statement is (from Popper) the stronger one.

I see. That's very interesting. Again, I'll have to borrow that one!

Then you have two separate universes. I suppose that is a fourth case.

Actually, I was expecting something along the lines of: "If it doesn't interact with matter, then it doesn't exist." Because here, if you admit that the world of the mind may exist independantly, you also admit that existence is independant. You therefore claim that something may exist that is not provable in principle. Now that I recall, this was at the root of your argument.

Well, and example of (i) might be:

There are two fundamental natures of existence: Mind and matter. Mind and matter both follow consistent laws in their interactions with themselves. They also follow consistent laws when they interact with each other.

That collapses to monism.

A type (ii) would be Cartesian dualism:

There are two fundamental natures of existence: Mind and matter. Mind and matter both follow consistent laws in their interactions with themselves. They never interact with each other, being entirely distinct and separate. The pineal gland is the mediator between mind and matter.

Saying that they two realities don't interact, and then saying they do interact, makes the statement itself contradictory.

So, Descartes said that mind and matter did not interact, except by the pineal gland? lol! Yes, this statement indeed is a contradiction. But the statement that mind and matter do not ever interact is not.

If mind is a real and separate thing and doesn't interact with matter, then our minds can't study the material universe at all!

Instead of using the term 'mind', why don't we use the term 'spirit'. The 'spirit of the dead' (whatever that means) could very well exist in another reality, independantly of us.

What it says is that everything observable is explicable in terms of something else, also observable. That's what falls out of the two axioms. Supernaturalism breaks one or both of the axioms.

Perhaps naturalism says that, but certainly not science. Science is an experimental way to obtain knowledge. We 'try stuff' and see what works. It never assumes that "everything observable is explicable in terms of something else, also observable". So far, this has been true. But, again, it is not an axiom of science. We might one day encounter some phenomenon that cannot be explained by science. And science will still work for everything else.

That is partly true. Depending on the nature and degree of the supernatural intervention, science may still work in a practical sense, though it fails as a philosophy of knowledge.

Exactly.

 

[Gertrude]

That's true, but not what I'm getting at.

Yes it is. Precisely. You say that an event can exist for one observer and not for another one because of relativity. But this is wrong. As I said, an event that exists in the rest frame exists also in all other frames because their time scale is longer. And an event that did not happen in the rest frame, of course, did not happen for anybody.

The problem is that unless you take relativity into account, you can have multiple contradictory statements about the existence of the same object, all of which are equally valid.

This was what I was adressing. It is wrong. The only difference from one frame to the other is the length of time. Existence in itself is independant. An event will exist for any observer. It may not have the same length, but the existence is indisputable.

To assert that existence is independent of relativity is to assert a universal preferred frame of reference.

Wrong. The first postulate of relativity states that there is no preferred frame of reference, ie. the laws of physics are the same in all frames. What I just said is in complete agreement with this. If it exists, it exists for everybody. Not for the same period of time, not with the same physical length, but it nevertheless exists.

 

[PixyMisa]

But you have not defined what the rules are exactly. Actually, nobody knows! Science tries to find out what they are. Who knows, perhaps naughty tricksy demons are part of the rules!

If so, they are naught tricksy consistent demons, and so subject to scientific investigation.

The fact that we obtain information, strictly speaking, does not guarantee the validity of said information.

No, it doesn't, but we are guaranteed that the we can study the question of the validity of the information using the same approach.

Again, we have said there were rules, but not what they were. By the way, the axioms state that there are rules but certainly not that these are all there is.

No, the axioms do say that these are all there is. If the universe is causally closed, there isn't anything else. If it's consistent, it's consistent.

I disagree for the sake of disagreement. I certainly won't bother to question the nature of my vision if I see a car rolling full blast towards me. But strictly speaking, the argument is fallacious for the reasons I stated.

Nope. We have stated that the material universe is all there is. Therefore there is nothing our senses can do but represent material events. Hallucinations are material events.

Absolutely. But it could be argued that our senses are useful only in a self-preservation way. Our senses are a result of evolution and are useful in finding food, communicating with other humans and detecting danger. That they are a valid tool to gain knowledge is only an assumption and must be stated as such.

Nope. All they have to do is present some sort of information from the material world. We know that they are often invalid. We have worked out when and how this happens, and we deal with it.

Yes, it continues. But it may not make up for everything. There may be areas of knowledge that we will never know about due to our own limitations (and that of science).

I'm not sure what you mean. If you are saying that we can't assemble a complete body of facts about everything in the universe, then that is certainly true. If you are saying we can't assemble a complete body of rules governing everything in the universe, that doesn't follow at all.

I agree that there is no other way for us to gain knowledge. The question concerns the validity of this knowledge.

Well, there are two things there:

First, our axioms may be wrong.

Second, we can derive from the axioms that all knowledge is conditional. Our senses represent some sort of causal chain to material events, but there is no deductive proof possible of the nature of that causal chain, because all evidence as to that also depends on our senses, and we don't know in the first place how reliable our senses are.

I see. That's very interesting. Again, I'll have to borrow that one!

It's worth looking into Karl Popper. He's the one who really laid out the concept of falsifiability as the keystone of science. Some philosophers disagree with him, but they're the same ones who are still wrestling with 2500-year-old problems.

Actually, I was expecting something along the lines of: "If it doesn't interact with matter, then it doesn't exist." Because here, if you admit that the world of the mind may exist independantly, you also admit that existence is independant. You therefore claim that something may exist that is not provable in principle. Now that I recall, this was at the root of your argument.

Essentially, as separate universes, you can't make a meaningful statement in one about the existence of the other. You can speculate, of course, but that's different.

So, Descartes said that mind and matter did not interact, except by the pineal gland? lol! Yes, this statement indeed is a contradiction. But the statement that mind and matter do not ever interact is not.

Well, Descartes was speculating, but that's one of his ideas, yeah. Very smart guy, but totally off the wall on that one.

Instead of using the term 'mind', why don't we use the term 'spirit'. The 'spirit of the dead' (whatever that means) could very well exist in another reality, independantly of us.

Yeah, and we'd never know. And it would never know we exist. Which is not what dualists mean when they suggest such a thing.

Perhaps naturalism says that, but certainly not science. Science is an experimental way to obtain knowledge. We 'try stuff' and see what works. It never assumes that "everything observable is explicable in terms of something else, also observable".

It does, in fact. It's a tentative assumption: "Let's assume this and see how we go." And it's a straightforward consequence of the two axioms. But you don't have to keep it in mind all the time while you're doing research - unless you're doing string theory or cosmology.

 

[PixyMisa]

Yes it is. Precisely. You say that an event can exist for one observer and not for another one because of relativity. But this is wrong. As I said, an event that exists in the rest frame exists also in all other frames because their time scale is longer. And an event that did not happen in the rest frame, of course, did not happen for anybody.

No, you've missed it again. Actually, okay, forget moving frames of reference for a moment; motion isn't critical. Just consider what you can observe, given your position in space-time.

Events have a beginning and an end. For any given event, you can have an observer who has not seen the beginning, an observer who has seen the beginning and not the end, and an observer who has seen the beginning and the end.

The three observers will make three contradictory but equally valid statements regarding the existence of that event. The only way to reconcile those statements is via relativity.

 

[Gertrude]

Or... So it seems to me.

As far as I can see, for to exist to exist as a meaningful verb in relation to the material universe, it must take relativity into account.

As I said earlier, the alternative is to abandon time (specifically, epoch) as an attribute of existence, so it would be valid to say that dinosaurs and trilobites and the burned-out white dwarf husk of the Sun all exist. That's not wrong, and it avoids the relativity issues, but it changes the meaning of the word sharply from its common usage.

I see that you are already accepting the notion of independance of existence! If not, all you would have to say is that dinosaurs do not exist to us because, having lived in our frame (well, OK, I admit that since the earth is subject to gravity, this may not be completely valid), time is not relative. But even if time is a little bit relative in our frame, the time that has elapsed since their disparition is far greater than the effects of relativity. I therefore feel comfortable saying that dinosaurs are dead, at least as seen from here

Speaking of 'Time' with a capital 'T' when the reference frames are not inertial is pointless imho. Time is a relative concept and this should not be forgotten. Before we abandon time in the concept of existence, we should be careful in describing exactly what it means. You are comparing 'times' from different inertial frames. And they cannot be compared. Saying that 'right now' a verrrryyyy fast observer may still be seeing dinosaurs is comparing two different times: our 'right now' and the observer's own time. That this comparison is valid, I highly doubt it...

ETA: I should have added: we certainly can compare durations: we do it all the time. But comparing the notion of 'right now' is meaningless.

 

[Gertrude]

No, you've missed it again. Actually, okay, forget moving frames of reference for a moment; motion isn't critical. Just consider what you can observe, given your position in space-time.

Ok. But realise that this is a completely different problem that has nothing whatsoever to do with relativity. If you speak of the distance travelled by light to go from event to observer, then you are right that aliens at the correct distance from us may be seeing dinosaurs at this very moment.

Events have a beginning and an end. For any given event, you can have an observer who has not seen the beginning, an observer who has seen the beginning and not the end, and an observer who has seen the beginning and the end.

No. All obervers will see the beginning, the middle and the end. In a moving frame or not.

The three observers will make three contradictory but equally valid statements regarding the existence of that event. The only way to reconcile those statements is via relativity.

They won't. If they are in movement relative to the others, all that will change is the duration (and physical length) of the object/event. As I already said, if the event exists in the rest frame, the it exists in all frames. And it exists completely: beginning, middle and end. If it doesn't occur in the rest frame, it occurs in no other frame.

 

[Gertrude]

If so, they are naught tricksy consistent demons, and so subject to scientific investigation.

lol. Right.

No, it doesn't, but we are guaranteed that the we can study the question of the validity of the information using the same approach.

What tells you that this approach guarantees the validity of your information?

No, the axioms do say that these are all there is. If the universe is causally closed, there isn't anything else. If it's consistent, it's consistent.

The axioms of science don't pretend that the physical rules are all there is. Science 'tries' different theories and sees which ones produces results. E&M is a rule, but first and foremost, like any other scientific law, it starts by being an experimental constatation. We constat that there is such and such rule but in no case do we pretend that no other rule (physical or not) exist.

Nope. We have stated that the material universe is all there is. Therefore there is nothing our senses can do but represent material events. Hallucinations are material events.

Again, science does not make the assumption that the material universe is all there is. It makes the assumption that 1) we can trust our perceptions (ie. experimentation is a valid method to obtain knowledge) and 2) logic can accurately describe these observed phenomenons. Science says nothing about the material world and what can or cannot exist. We notice that something exist and we try to describe it by scientifical methods. If it works, good. If it doesn't work, too bad. So far, a materialistic explaination (which is all science can provide) has always proven sufficient, but if one day it does not, science will not fall apart as a tool.

Nope. All they have to do is present some sort of information from the material world. We know that they are often invalid. We have worked out when and how this happens, and we deal with it.

I use 'senses' to mean 'perception'. Or as I said earlier (with your help ): "Both the way we interpret our perceptions and the way our perceptions work."

I'm not sure what you mean. If you are saying that we can't assemble a complete body of facts about everything in the universe, then that is certainly true. If you are saying we can't assemble a complete body of rules governing everything in the universe, that doesn't follow at all.

Why does it not follow? It seems like a perfectly reasonable possibility to me.

Well, there are two things there:

First, our axioms may be wrong.

Second, we can derive from the axioms that all knowledge is conditional. Our senses represent some sort of causal chain to material events, but there is no deductive proof possible of the nature of that causal chain, because all evidence as to that also depends on our senses, and we don't know in the first place how reliable our senses are.

EXACTLY!!! Forget the arguments on senses and perceptions: I believe we agree.

It's worth looking into Karl Popper. He's the one who really laid out the concept of falsifiability as the keystone of science. Some philosophers disagree with him, but they're the same ones who are still wrestling with 2500-year-old problems.

I will sure remember that name. Any book suggestion?

Essentially, as separate universes, you can't make a meaningful statement in one about the existence of the other. You can speculate, of course, but that's different.

Right. And that's different from your original argument. You initially said: if we can't measure it in principle, then it does not exist. Here, you say that we "can't make a meaningful statement in one about the existence of the other". This statement does not claim the absence of what we can't measure. It only states the lack of meaningful statement on our part. And I fully agree.

Yeah, and we'd never know. And it would never know we exist. Which is not what dualists mean when they suggest such a thing.

OK. But in such a case, we must admit that existence can be without interaction. That is, the spiritual world may exist without the possibility for us to measure it, even in principle. It's just that we'll never know.

It does, in fact. It's a tentative assumption: "Let's assume this and see how we go." And it's a straightforward consequence of the two axioms.

If the assumption doesn't prove to be valid, science won't fall apart. It will still work in many areas. It is in this sense that I say "everything observable is explicable in terms of something else, also observable" is not an axiom of science. Not even a general assumption. It works and has proven true so far. But science will only see its own limit if confronted to a case where the assumption won't be valid. Science will still work within the limit.

But you don't have to keep it in mind all the time while you're doing research - unless you're doing string theory or cosmology.

 

[PixyMisa]

Ok. But realise that this is a completely different problem that has nothing whatsoever to do with relativity. If you speak of the distance travelled by light to go from event to observer, then you are right that aliens at the correct distance from us may be seeing dinosaurs at this very moment.

Yes, exactly. Are they wrong?

No. All obervers will see the beginning, the middle and the end. In a moving frame or not.

But when?

Let's put it another way, in more directly scientific terms: For any two observers who can communicate with each other, their observations of the existence of any event will coincide, once relativity is taken into account.

For any two observers who cannot communicate with each other due to relativity), their observations of the existence of any event may be contradictory, but they will be unable to communicate this fact with each other.

So any beings in communication will be able to construct consistent statements of existence for any event they can observe. This does not apply for beings whose light cones do not overlap; they can have valid but contradictory statements of existence for any given event. Once their light cones do overlap, this changes, of course.

If you assert that something exists for all people, the question is, when is this so? There are people who can validly deny this, but you can't communicate with them.

So another way to view this is that existence travels at the speed of light.

 

[PixyMisa]

What tells you that this approach guarantees the validity of your information?

It guarantees there is some signal in the noise, and that's all we need.

Why does it not follow? It seems like a perfectly reasonable possibility to me.

I'm not saying that it's impossible; just that it is unfounded.

I will sure remember that name. Any book suggestion?

Not for Popper, but that's definitely worth asking in the Science forum.

Right. And that's different from your original argument. You initially said: if we can't measure it in principle, then it does not exist. Here, you say that we "can't make a meaningful statement in one about the existence of the other".

It's the same thing.

OK. But in such a case, we must admit that existence can be without interaction. That is, the spiritual world may exist without the possibility for us to measure it, even in principle. It's just that we'll never know.

My point is, that there is now no sense in which it exists, and therefore it does not exist.

 

[Gertrude]

Yes, exactly. Are they wrong?

Of course not! Someone sufficiently far may not even think that there are humans on earth. But does that mean we don't exist?

But when?

What do you mean? Are you implying that there is a universal time scale that everyone's clock measures against?

Let's put it another way, in more directly scientific terms: For any two observers who can communicate with each other, their observations of the existence of any event will coincide, once relativity is taken into account.

Relativity does not have to be taken into account. For two inertial frames with different velocities, the observations will coincide perfectly except for physical lengths and durations.

For any two observers who cannot communicate with each other due to relativity),

Do you mean that they cannot communicate because they are outside each other's light cone (or sufficiently far, depending on the type of transmission)? If so, then it is not relativity. It is simply the fact that nothing travels faster than light, which is a postulate of relativity, but not relativity itself, which deals with the physical laws in inertial reference frames (special relativity) and accelerating or non inertial reference frames (GR).

their observations of the existence of any event may be contradictory, but they will be unable to communicate this fact with each other.

It will not be contradictory. Only delayed (if separated by different distances from the object) or modified in scale (relativity).

So any beings in communication will be able to construct consistent statements of existence for any event they can observe. This does not apply for beings whose light cones do not overlap; they can have valid but contradictory statements of existence for any given event. Once their light cones do overlap, this changes, of course.

Whether or not they can see planet 4831964 does not change the fact that planet 4831964 exists. The reference should always be the rest frame (relaivity) or a close observer (distance).

If you assert that something exists for all people, the question is, when is this so?

Always.

There are people who can validly deny this, but you can't communicate with them.

That makes no difference to the fact that this something exists.

So another way to view this is that existence travels at the speed of light.

Information about existence travels at the speed of light. But existence is independant of this information.

 

[Gertrude]

It guarantees there is some signal in the noise, and that's all we need.

In what does "some signal" guarantee the validity of the information?

I'm not saying that it's impossible; just that it is unfounded.

Hence my use of the words "perfectly reasonable possibility".

Not for Popper, but that's definitely worth asking in the Science forum.

I'll do my research first and I certainly will use the Science forum. Thanks!

It's the same thing.

You mention two worlds, each completely separated from the other. And we agree that no information can be transmitted from one two the other. For a person in universe A, universe B does not exist. And vice versa for a person in universe B. However, the independant truth is that both universes exist. This is the meaning that I give to existence. Actually, it really boils down to the discussion in the other post about existence and physical laws.

My point is, that there is now no sense in which it exists, and therefore it does not exist.

At this point, I think we'll have to agree to disagree.

 

[PixyMisa]

Information about existence travels at the speed of light. But existence is independant of this information.

Aha! Well said.

What I'm saying is that all statements of existence are statements about information. When we assert that something exists, we are asserting that we have, or can obtain, in principle, information relating to that thing.

Disjoint light cones and causally separate universes preclude this, and therefore preclude meaningful statements of existence. (We can infer the continued existence of objects inside our light cone, but that's different.)

 

[PixyMisa]

However, the independant truth is that both universes exist.

That's the problem. There isn't any independent truth.