Is R real?

[Ahab]

Yes, but 1 + 1 = 2 is true sitting in a truck or sanding on the moon...how about that!!!

It's a definitional truth.

"1" and "+" and "=" and "2" are all defined ahead of time.

It is a truth that flows from defining things.

If there are no definitions there are no truths. So you can have human civilizations without mathematics.

It is a truth to something that understands the definitions.

Without the thing that understands there are no truths.

It is not a truth to a fish.

Agreed. Mathematical propositions are a part of our norms of representation. They license the transformations of empirical propositions concerning quantities or magnitudes of things.

We don't use reality to justify our mathematical concepts. Rather mathematical concepts are used to describe reality.

 

[untermensche]

I don't see it exactly that way.

Models do not describe reality.

They model real conditions.

And a model is not true or false.

It is accurate or inaccurate.

A model either conforms with real conditions so that predictions can be made or it does not.

And I don't see models as containing numbers.

They contain numerical representations of real quantities.

So 50 mph is not the number 50.

It is the speed (something "real") of some "real" object represented with a number since quantities can be represented with numbers.

There is a human limit to how small a quantity can be distinguished.

 

[Ahab]

I don't see it exactly that way.

Models do not describe reality.

They model real conditions.

And a model is not true or false.

It is accurate or inaccurate.

A model either conforms with real conditions so that predictions can be made or it does not.

And I don't see models as containing numbers.

They contain numerical representations of real quantities.

So 50 mph is not the number 50.

It is the speed (something "real") of some "real" object represented with a number since quantities can be represented with numbers.

There is a human limit to how small a quantity can be distinguished.

Actually agree with much of the above. My above comments in post #101 were not limited to scientific models. They also referred to the descriptions used by humans in their daily activities.

Not sure I understand all the particular distinctions you are making. In any case, have to head to work. Thanks for giving me something to think about.

 

[Speakpigeon]

Please justify.
EB

The JTB analysis of knowledge does not reveal the sufficient conditions of knowledge.

So, you're not claiming that a belief which is true and justified constitute knowledge?
EB

 

[fast]

Please justify.
EB

The JTB analysis of knowledge does not reveal the sufficient conditions of knowledge.

So, you're not claiming that a belief which is true and justified constitute knowledge?

EB

I’m treating “constitute” much like I would “guarantee” or “must.”

If the belief and justification conditions are met, then there’s a good and more than minimal possibility that the justified belief may (and not merely might) be true and thus the justified belief may be knowledge; it’s contingent upon whether or not the truth condition is in fact met, which is not dependent on the other conditions but rather facts or worldly state of affairs. Even then, there are situations where we don’t really know even if we think we do.

 

[Speakpigeon]

So, you're not claiming that a belief which is true and justified constitute knowledge?

EB

I’m treating “constitute” much like I would “guarantee” or “must.”

If the belief and justification conditions are met, then there’s a good and more than minimal possibility that the justified belief may (and not merely might) be true and thus the justified belief may be knowledge; it’s contingent upon whether or not the truth condition is in fact met, which is not dependent on the other conditions but rather facts or worldly state of affairs. Even then, there are situations where we don’t really know even if we think we do.

Yeah, I guess we could conceive of knowledge as a situation whereby an information system has data relevant to something in the world out there. Data would be knowledge by virtue of a general "state of affair" whereby the data somehow would get to be relevant. But then, a thermometer would have to be said to know the temperature. Being pragmatic thingies, we can accommodate our vocabulary to mean pretty much whatever we need it to mean. You'll forgive me if I don't follow this route you've been travelling on.

And now back to R.
EB

 

[Speakpigeon]

As I understand it, we have an intuitive notion of the continuity of space and time. Unfortunately, it seems there's no way we could even in principle prove space and time are continuous in this sense. However, mathematicians, well, Descartes as it turns out, invented the mathematical concept of the set of Real numbers, which seems now accepted as a very good representation of the continuity of space and time. But I have a problem with that.

Before I go into my beef about Reals, I would like to know what you think of this idea that the set of Real numbers would be a good model for the continuity of space and time.

Thanks.
EB

Nota. I think it's mostly not a mathematical question but mathematicians pros and amateurs are welcome to contribute.

This is the OP.
EB

 

[fast]

What would be an example of a model of what a model is a model of when what the model is a model of isn’t physical?

That’s a mouthful; let me explain. Models are generally physical in nature and sized to be a representative of something else. For example, you may be interested in building a hotel. Prior to initiating the construction of the actual hotel, you may be interested in building a small scale model that’s reflective of what the final build of the future hotel will be like.

We can also size a model larger for small microscopic objects; either way, there is a physical scaled difference between (X, the model) and (Y, what the model is a model of). In this instance, X (the model—or hotel model) would be smaller than Y (what the model is a model of—namely, the hotel).

There are many models. There are models of cars. There are model airplanes. I’ve even seen models of our solar system. Models with moving parts are pretty cool (like a small model of a large clock tower—or a small model of our solar system with beams that are in motion via gears.)

I think it’s important that as we start speaking of models (and i’ll be opened minded and generous regarding the scope to which the term “model” should apply before looking for a more encompassing term that might better articulate what you’re after; however, let us not lose sight of the important divide between what I’ve regarded and stipulated as X (the model) vs Y (what’s being modeled).

You have used the word “continuity.” Meaning, or perhaps it’s better to say, you are telling me that it’s neither space nor time that is under discussion. You’re speaking (explicitly saying) continulity of space and time, so although it’s not continuity itself you’re eluding to when making your inquiry but rather if real numbers model the continuity of space and time.

The point is, what is Y? The continuity of space? The continuity of time? The continuity of space time? What needs to be said, I feel, is that you’re not talking about the universe (like a solar system) with dimensions whereby a physical model could be constructed.

Real numbers do have the appearance of being continuous—at least to me they seem to go on and on, so there is a semblance of similarity on that notion; hence, X (Real Numbers) are continuous and Y (the continuous portions of space and time) are continuous.

Even if time had a start (for instance no time preceded the Big Bang), we could overlap time over a graph paper grid of continuous real numbers (especially natural numbers) and i’d think it would accommodate a melding of the two—much like how science tries to utilize numbers to explain everything in the universe.

What I’m looking for is a basic starting point for comparison. If you asked if X was a good model for Y where X and Y were physical, I would try to start out as I have—talking of hotel models being a model for hotels; then, I’d build from there, but I have reservations about coming up with a good model for something that seems more like dimensions.

People get so loose with words and speak so carefree that it can be difficult to grasp how critical I should be. You made a comment earlier that carried the implication that thermometers could hold beliefs if ... . I need to know where flexibility should be given in pursuit of your quest.

Maybe you have an underlying question that need not have us clasp for the truth with such rigidity. Do you think numbers could be a good model for the middle half of the alphabet? Each letter goes by one at a time just as pretty as a natural number goes by one at a time. Even if space and time has an end while numbers didn’t, there’s still a comparative similarity as shown by layering a film of letters over a series of numbers.

Anyhow, just wanted to throw a few thoughts out there.

 

[Speakpigeon]

What would be an example of a model of what a model is a model of when what the model is a model of isn’t physical?

First, thanks for showing you understand the OP, unlike the usual flying squadron of numpty dumpties.

Yes, this is a real difficulty. Our sensory organs are excellent for us to make comparisons we can trust between the model of a material object and the object so modelled. However, the way science works, we moved from relatively simple material models of material objects, to mathematical theories which are abstract models of things which we don't actually know that they exists as such, such as the laws of nature, or even physical things such as mass, spin, energy, space, time etc., things therefore that we don't know if they are physical objects and mere abstractions. So, as I see it, any scientific theory is just such a putative abstract model, and accordingly, elements in these theories may have to be regarded as models of properties of physical objects, properties that we don't know that they exist, and which therefore we don't know if they are physical or abstract. Hence the necessity, as I see, of taking R as a model, and indeed as the current scientific model, of this putative property which is the continuity of physical quantities, like energy, space or time.

You have used the word “continuity.” Meaning, or perhaps it’s better to say, you are telling me that it’s neither space nor time that is under discussion. You’re speaking (explicitly saying) continulity of space and time, so although it’s not continuity itself you’re eluding to when making your inquiry but rather if real numbers model the continuity of space and time.

Yes.

The point is, what is Y? The continuity of space? The continuity of time? The continuity of space time? What needs to be said, I feel, is that you’re not talking about the universe (like a solar system) with dimensions whereby a physical model could be constructed.

Yes.

What I’m looking for is a basic starting point for comparison. If you asked if X was a good model for Y where X and Y were physical, I would try to start out as I have—talking of hotel models being a model for hotels; then, I’d build from there, but I have reservations about coming up with a good model for something that seems more like dimensions.

I would suggest scientific theories as our best example of abstract models of things we can possibly observe like we observe the sun setting over the horizon.

Still, those are nothing new. I see science as just what all of us do all the time in the course of our lives, including numpty dumpties. For example, we have a model for our feeling, sensations, impressions etc. Things arguably not physical which are very ordinary things, like pain and the colours we experience subjectively.

People get so loose with words and speak so carefree that it can be difficult to grasp how critical I should be. You made a comment earlier that carried the implication that thermometers could hold beliefs if ... . I need to know where flexibility should be given in pursuit of your quest.

I wan't being flexible with words. I was showing the absurdity of your theory of knowledge as justified true belief by pointing out one of its absurd implication.

Maybe you have an underlying question that need not have us clasp for the truth with such rigidity. Do you think numbers could be a good model for the middle half of the alphabet? Each letter goes by one at a time just as pretty as a natural number goes by one at a time. Even if space and time has an end while numbers didn’t, there’s still a comparative similarity as shown by layering a film of letters over a series of numbers.

We can certainly count letters and I'm unable to conceive of any alphabetical object we couldn't count the letters of which, at least in principle.

Anyhow, just wanted to throw a few thoughts out there.

Thanks.

I guess you have to think of JTB as such a model of knowledge, knowledge which we're as yet effectively unable to show that it is physical.
EB

 

[fast]

Electrons exist. There are things about them that some sciencey types can confidently speak about. The problem is that although technically they are observable, they are not directly observable. They are what scientists describe as being indirectly observable. They’re just that doggone small. Even with the most powerful microscopes and technologies at our disposal, we cannot in any way, shape, or form even so much as draw one that uncontroversially depicts their actual geometric shape.

Any models that are brainstormed would be subjectively biased—perhaps great as an explanatory teaching tool but severely lacking at physical representational accuracy. It’s because of that great divide between what is directly observable and indirectly observable—unless the extent of our indirect observations are so great as to allow us to map a true representative model of the indirectly observable yet physical thing we call the electron.

The artist can bring his skills to bare and through the fruit of both his learning and skill build a model to (and with purpose) help deliver to mass audiences what a true electron is like, but isn’t failure immenent? Sure, we can suck it up and move forward without having a true model and continue still to learn, but what we learn (even if true) does nothing about the models precision.

 

[steve_bank]

On that one I disagree. Electron is a tag for a collection of properties. Whether it exists as we may imagine is unknown.

 

[untermensche]

You can do a lot with organic chemistry if you imagine there are electrons moving around.

 

[fast]

On that one I disagree. Electron is a tag for a collection of properties. Whether it exists as we may imagine is unknown.

What line items do we disagree?

 

[Speakpigeon]

Electrons exist. There are things about them that some sciencey types can confidently speak about. The problem is that although technically they are observable, they are not directly observable. They are what scientists describe as being indirectly observable. They’re just that doggone small. Even with the most powerful microscopes and technologies at our disposal, we cannot in any way, shape, or form even so much as draw one that uncontroversially depicts their actual geometric shape.

Any models that are brainstormed would be subjectively biased—perhaps great as an explanatory teaching tool but severely lacking at physical representational accuracy. It’s because of that great divide between what is directly observable and indirectly observable—unless the extent of our indirect observations are so great as to allow us to map a true representative model of the indirectly observable yet physical thing we call the electron.

The artist can bring his skills to bare and through the fruit of both his learning and skill build a model to (and with purpose) help deliver to mass audiences what a true electron is like, but isn’t failure immenent? Sure, we can suck it up and move forward without having a true model and continue still to learn, but what we learn (even if true) does nothing about the models precision.

I'm not sure you're addressing the OP's question or the question of knowledge. The question isn't about whether the model is true but whether it's a good model.

the set of Real numbers would be a good model for the continuity of space and time.

So, what's "good"? Well, the OP was an invitation to explain in what sense of "good", according to you, the R set could be a good model of the continuity of space and time. So, as far as I understand what you're saying here, although helpful, it's a shite poor model, because, like for the electron, continuity of space and time is something we have very good reason to think exists but that we don't actually know it because it's beyond direct observation. So, you think we know things we can directly observe, like trees and dogs, and perhaps things we can reliably infer from direct observation. So, in practice, justification is just direct observation and some kind of robust inference from it. And, if we can't say much about the electron, how could we say anything about the continuity of space and time? So, R is just a shite poor model. Is that it?
EB

 

[fast]

The continuity (which neither implies nor negates infinity) of real numbers appears at least at first glance to be a characteristic shared by the continuity of space and time.

Whether something is a good model for something else codepends on it being both good and a model. If you deny that it’s a good model, fine, but why? If you hold that (and are correct in that) it’s not a model at all, then surely it’s not a good model—or a bad one. May as well simply deny that it’s a model; however, if you accept that it’s a model and maintain that it’s not a good model, then you think not real numbers (but the continuity of real numbers) in some way substantive way fail to model well not space and time but rather (the continuity of space and time). But why?

What drives all this? What direction does the denial carry us? About knowledge? About models? Science? Or, is there a deep-seated ideological view at work here?

The reason it’s a good model is because of its shared traits. Take any set of two points of both the model and what’s modeled and compare them. Both seem unbroken and consistent. Between 50 and 60, there’s a 56 just where I’d expect it to be. 2pm on October 5th 1992 is right where it ought to be. Half way between here and there hasn’t slipped away.

I looked up “continuity” and noticed a section where the author intended to show it used in a sentence. He spoke of the continuity of employment. I liked that example. Of course, as any financial guru will tell ya, one’s employment will end one day, some way, some how. New job, fired, quit, die! It’ll end. But, so what! There is a continuity to employment. Many people go to work, day in day out, for years. Sure, they may have a day off once in a while, but their employment continues over a portion of time. That’s what prompted me to say that continuity doesn’t imply nor negate infinity.

There appears to be the aroma of infinity in the air when it comes to numbers, and if real numbers (well, make that the continuity of real numbers) is the model, I don’t see how what it’s a model of has to share every trait in exactness with what’s being modeled.

ETA:
Afterthought

Numbers are like the tick marks for dimensions. Imagine a railroad track where each rail is a dimension. Space can be one and time the other. Numbers would be the boards between them.

 

[Speakpigeon]

The continuity (which neither implies nor negates infinity) of real numbers appears at least at first glance to be a characteristic shared by the continuity of space and time.

Whether something is a good model for something else codepends on it being both good and a model. If you deny that it’s a good model, fine, but why? If you hold that (and are correct in that) it’s not a model at all, then surely it’s not a good model—or a bad one. May as well simply deny that it’s a model; however, if you accept that it’s a model and maintain that it’s not a good model, then you think not real numbers (but the continuity of real numbers) in some way substantive way fail to model well not space and time but rather (the continuity of space and time). But why?

What drives all this? What direction does the denial carry us? About knowledge? About models? Science? Or, is there a deep-seated ideological view at work here?

The reason it’s a good model is because of its shared traits. Take any set of two points of both the model and what’s modeled and compare them. Both seem unbroken and consistent. Between 50 and 60, there’s a 56 just where I’d expect it to be. 2pm on October 5th 1992 is right where it ought to be. Half way between here and there hasn’t slipped away.

I looked up “continuity” and noticed a section where the author intended to show it used in a sentence. He spoke of the continuity of employment. I liked that example. Of course, as any financial guru will tell ya, one’s employment will end one day, some way, some how. New job, fired, quit, die! It’ll end. But, so what! There is a continuity to employment. Many people go to work, day in day out, for years. Sure, they may have a day off once in a while, but their employment continues over a portion of time. That’s what prompted me to say that continuity doesn’t imply nor negate infinity.

There appears to be the aroma of infinity in the air when it comes to numbers, and if real numbers (well, make that the continuity of real numbers) is the model, I don’t see how what it’s a model of has to share every trait in exactness with what’s being modeled.

ETA:
Afterthought

Numbers are like the tick marks for dimensions. Imagine a railroad track where each rail is a dimension. Space can be one and time the other. Numbers would be the boards between them.

Not much to add for now except about continuity. There is "macroscopic" notion of continuity, which resides in the fact that there isn't any big hole in the fabric of the thing. Continuity of R is supposed to go up to the infinitesimal. Not only is there no "big hole", but there is no hole at all. Not even an infinitesimally small hole apparently.

And also, the OP's question is a straightforward one. It is what it says on the tin.
EB

 

[Bomb#20]

You seem to have changed the subject there.

I never changed the story. I have made my semantic of truth clear enough here in response to BWE earlier in this thread:

I didn't say you changed the story; I said you changed the subject. Fromderinside asked for an example of a truth. Fast and I gave him some examples. Your critique of our responses was "that would be a statement about an objective fact and that's the kind of statement we don't really know whether they are true." So I'm pointing out that fromderinside didn't ask for an example of a truth we know. He just asked for a truth. If what we gave him were truths we don't know, then we gave him truths we don't know, thereby satisfying his request. A truth we don't know is a truth.

On the other hand, you sure are taking your own assumptions as self-evident truths.

I expect that if pressed, you will identify these assumptions, and then I'll point out I was assuming nothing of the sort, and then you'll insist, without proof, that I was, and we'll be at an impasse.

Fromderinside was asking for an example of a truth, not an example of a truth we know. He and fast and I were talking ontology; you're wandering off into epistemology. Mammals evolved from reptiles even when we don't know it. That mammals evolved from reptiles was already a truth before there were even any mammals smart enough to know the difference between a mammal and a reptile.

Sorry, I'm not interested in using the word "true" in lieu of the perfectly good word "real". What's wrong with the word "real"? Is it too cheap for your standing?

What the devil are you on about? I used the word "truth" because it's the word you and fromderinside used in the posts I was replying to. What, you feel I ought to have read your mind and realized you'd suddenly start having a problem with it?

Truth in the sense you suggest is typical of metaphysical musing. I don't do metaphysical truth.

I'm only using the word 'truth" according to this definition:

a. Conformity to fact or actuality: Does this story have any truth?

I didn't suggest any sense of "truth" other than that one.

Oh, and this one, too. See? I didn't change the subject.

true
adj. 1. a. Consistent with fact or reality

That's not evidence that you didn't change the subject -- nobody said you changed the way "true" was used. Your change to the subject was bringing in "know".

The way you are suggesting we use the word "truth", I don't see how our debate here about whether there are truths could possibly make sense. It would be like asking whether there is a reality. Sorry, not for me.
EB

What you're saying about me is a figment of your imagination. I didn't make any suggestion for how we use the word "truth". Your proposal -- "Conformity to fact or actuality" -- is an entirely acceptable definition.

Not seeing how God coming for a visit would help you with this. But I suspect you already know quite a few truths about the physical world. I suspect you know enough to get you convicted if you lie to a cop, and you get charged with lying to a cop, and then your only defense is "I didn't know what I said to him was false because it was about the physical world and I don't know anything about the physical world." But you seem to be using "know" to mean metaphysical certainty, 0% probability of error. Normal English speakers don't use "know" that way.

Yes, they do. You seem unable to properly make the distinction between what we mean when we say we know something, which is indeed with zero possibility of error, and the fact that we accept we may be mistaken claiming we know something.

Who you calling "we", Kemosabe? Why should I accept your word for what I and other native English speakers mean by "know" when we use it? Am I supposed to be bowled over by your self-evident intellectual superiority? By your impressive level of fluency in a language not your own? By your self-confidence in making assertions you don't present evidence for? Or do you have some empirical linguistic evidence, drawn from observation of the speech acts of native English speakers, that falsifies the alternative hypothesis that we mean something different from what you say we mean and you just didn't learn this aspect of English semantics quite correctly?

When a criminal court is deciding whether a killing was negligence or murder, and is therefore looking into the question of whether the defendant knew the gun was loaded when he shot the deceased, the court will consider a witness saying he saw the defendant load the gun shortly before pulling the trigger to be relevant testimony. The fact that the defendant cannot possibly have had 0% probability of error on this point, because at the time he couldn't have completely ruled out the hypothesis that some mysterious stranger snuck into the room, chloroformed him, and unloaded the gun while he was temporarily blacked out, will not be considered a substantive reason to dismiss the witness's testimony. If "know" meant what you say it means, then courts would have to disregard all evidence as to who knew what.

The concept of knowledge implies absolute certainty <rest snipped>

I don't believe you. Why should I believe you?

What evidence is there that it's impossible for us to know some things about the physical world? You haven't offered us any.

Here you provide me with a good example of how careless people are with words. I didn't say it's impossible to know the physical world. I said we have evidence we can't know it.

You wrote "I'm in no doubt that they mean the same as me except for a few philosophers who tried to salvage the possibility that we should know some things about the physical world despite evidence to the contrary." Are you drawing some subtle distinction between "can't" and "impossible"? Are you quibbling about "we"? Do you perhaps mean there's evidence that humans can't, but no evidence that aliens from Aldebaran can't?

Whatever, have it your way. What evidence do you have that we can't know some things about the physical world? You haven't offered us any.

And that's not even anything particularly original to say. Tell me if you don't have the same evidence as we all do in this respect.
EB

I expect I have exactly the same evidence in this respect as we all do: none whatsoever.

It's no coincidence that Descartes came up with the Cogito and his notion of systematic doubt at the time of Copernic and Galileo. We've grown up.

If you recall, the cogito was not "I think, therefore I know nothing about the physical world." It was "I think, therefore I am." Systematic doubt leads to the conclusion that I do know something about the physical world. Specifically, "I am". The physical world contains me.

This is not what Descartes meant with the Cogito and he has been very explicit as to what it meant. He decided he could doubt his own body, and the physical world by implication, but not his own mind. He definitely didn't mean the "I am" of the Cogito with a claim to knowledge about the physical world. By the "I" of the Cogito, he meant the "thinking thing", not Descartes as the human person.
EB

And you think that's a counterargument to what I wrote, why? Where do you imagine you see me saying I know the physical world contains my own body, or Bomb#20 as the human person? By the "I" of the Cogito, Descartes meant the "thinking thing", and, now pay attention carefully here, that's what I meant too. The physical world contains the "thinking thing". That doesn't mean it contains my body. That doesn't mean it contains the earth, or electrons, or forces, or wave functions. I might be wrong about all those things, as Descartes' notion of systematic doubt shows. But it does contain me, the thinking thing.

It just happens that for a very long time we believed we knew the physical world. It's only recently, with science, that we have now more reasons to believe we now nothing about it.

Such as?

For example that we believe we are entirely biological organisms and that we can only interact with our environment through a perception system whose processes are entirely unconscious and therefore unknown to us except for the final representations we get within our mind of this environment. We know the representations, not what is represented. That's a fundamental fact about us. And whatever science we can do about our perception system cannot change this fact.
EB

Are you seriously under the impression that giving examples of things we can't know about the physical world qualifies as evidence we know nothing about it? That's illogical. You might as well try to prove man can never fly, because he has no wings, and try to prove it by presenting a list of wingless animals that can't fly.

You stipulate that you do know things, in your subjective experience. Therefore you think. Therefore you are. Being a logical person, by all means, please propose some hypothetical scenario, some possible world, that's consistent with you thinking and that does not involve a physical world containing you. If you exist in all possible worlds in which you think, that is sufficient for you to know that regardless of which one is the real world, the real world contains you.

Believing there's real world containing me is nothing like knowing it.

Believing you exist is nothing like knowing it. That's what the cogito is for. Now you know it, in addition to believing it.

What we mean by "physical world" isn't just any world out there. It's a specific kind of world.

So apply systematic doubt. What do you think we mean by "physical world" that you think excludes some of the "just any world out there" worlds? What possible world would qualify as non-physical?

I don't need to offer any particular scenario because anything is conceivable as long as it is logical.

Well, how do you expect to argue that some allegedly conceivable non-physical "just any world out there" world is logical if you won't describe it?

I can't exclude for example solipsism, the possibility that there would be nothing else but my conscious mind.

There you go. There's a particular scenario. So why do you think that isn't a physical world containing you? If solipsism is correct, you are the physical universe. Physics is the study of your conscious mind.

Or that there are different minds but only minds.

Cool, there's another particular scenario. In that possible world, physics is the study of minds.

I don't even have to try to conceive of a possible world that would be consistent with my subjective experience. There is an infinity of such possible world, and most of them wouldn't even qualify as "physical worlds", i.e. worlds consistently subjected to universal laws.
EB

You say "subjected to" as if laws of physics were like statutes, enacted by legislators, imposed on subjects. That's a very 17th-century way of looking at them. A "universal law" is simply a description of what the universe always does. We call "For every action there's an equal and opposite reaction" a universal law, not because the universe is "subjected to it" but because as far as we can tell there always is. If we demonstrate there's an exception then we'll change our minds about whether it's a law; we won't consider our universe an example of a nonphysical universe. So why would that eminently sensible attitude suddenly be wrong in a world with only minds? How do you figure some universe you conceive of might not always do whatever it always does? How is that logical?

If solipsism is correct and you are the only mind, then the universe consistently satisfies the proposition "Nothing but EB exists." In such a world, how do you figure that proposition doesn't qualify as a universal law?

And empirically, JTB appears to be a more accurate theory of the psychology of typical English speakers than the competing theory that "know" means "believe with a zero percent probability of being mistaken".

Knowledge means zero error, but claiming knowledge may be mistaken, and is mistaken most of the time according to historical record. We all understand that since this is how people speak. People who insists on something else have to be ideological motivated.
EB

Knowledge means* zero error, yes; but "zero error" does not mean "zero percent probability of being mistaken". You can have justified true belief of 100 things, each with 1% probability of error. You can be right about 99 of them and wrong about 1. In the case of the 99 that you're right about, that's zero error. In the case of the 1 you're wrong about, that's non-zero error and therefore not knowledge. But the fact that the 99 you're right about all had 1% probability of being mistaken does not imply that those 99 all have non-zero error. Therefore "zero error" and "non-zero probability of error" are logically compatible. Therefore the fact that knowledge means zero error is not grounds for claiming you don't know the 99 things you're right about with 1% chance of mistake.

(* Where "means" is being used in the sense of "implies". "Zero error" is an incomplete definition of knowledge.)

 

[Speakpigeon]

Fromderinside was asking for an example of a truth, not an example of a truth we know. He and fast and I were talking ontology; you're wandering off into epistemology. Mammals evolved from reptiles even when we don't know it. That mammals evolved from reptiles was already a truth before there were even any mammals smart enough to know the difference between a mammal and a reptile.

Sorry, I'm not interested in using the word "true" in lieu of the perfectly good word "real". What's wrong with the word "real"? Is it too cheap for your standing?

What the devil are you on about? I used the word "truth" because it's the word you and fromderinside used in the posts I was replying to. What, you feel I ought to have read your mind and realized you'd suddenly start having a problem with it?

Sorry, truths are just the statements of facts by someone who knows the facts. There aren't any truth free floating without somebody knowing them, as well as the relevant fact.

So the fact that mammals evolved from reptiles is a fact, not a truth as you said here.

If you know the fact that mammals evolved from reptiles then the statement "Mammals evolved from reptiles" is true and that's what people would call a "truth", but that's also the kind of things I say are not truths because we don't know whether the purported facts, for example that mammals evolved from reptiles, happened. Facts will be facts whether we know them or not, but truths are something else altogether. To know a truth, you need to know a statement, the statement has to be true, and you need to know it's true. An example of a truth would be "I'm in pain" uttered by someone in pain. Of course, he would be the only one to know it's true and therefore to know this particular truth.

So, don't complain. It's you who said "That mammals evolved from reptiles was already a truth". No, it's never been a truth. Possibly a fact, we don't know. If we knew, the statement of the fact would be a truth.

I can't read your mind. If you're not careful with the way you express yourself, or maybe if you're not to clear about what you mean, this will be your problem, not mine.
EB

 

[Speakpigeon]

Not seeing how God coming for a visit would help you with this. But I suspect you already know quite a few truths about the physical world. I suspect you know enough to get you convicted if you lie to a cop, and you get charged with lying to a cop, and then your only defense is "I didn't know what I said to him was false because it was about the physical world and I don't know anything about the physical world." But you seem to be using "know" to mean metaphysical certainty, 0% probability of error. Normal English speakers don't use "know" that way.

Yes, they do. You seem unable to properly make the distinction between what we mean when we say we know something, which is indeed with zero possibility of error, and the fact that we accept we may be mistaken claiming we know something.

Who you calling "we", Kemosabe? Why should I accept your word for what I and other native English speakers mean by "know" when we use it? Am I supposed to be bowled over by your self-evident intellectual superiority? By your impressive level of fluency in a language not your own? By your self-confidence in making assertions you don't present evidence for? Or do you have some empirical linguistic evidence, drawn from observation of the speech acts of native English speakers, that falsifies the alternative hypothesis that we mean something different from what you say we mean and you just didn't learn this aspect of English semantics quite correctly?

When a criminal court is deciding whether a killing was negligence or murder, and is therefore looking into the question of whether the defendant knew the gun was loaded when he shot the deceased, the court will consider a witness saying he saw the defendant load the gun shortly before pulling the trigger to be relevant testimony. The fact that the defendant cannot possibly have had 0% probability of error on this point, because at the time he couldn't have completely ruled out the hypothesis that some mysterious stranger snuck into the room, chloroformed him, and unloaded the gun while he was temporarily blacked out, will not be considered a substantive reason to dismiss the witness's testimony. If "know" meant what you say it means, then courts would have to disregard all evidence as to who knew what.

Criminal courts don't pretend to know whether the suspect is guilty. They assess the overall plausibility of alternative scenarios. When they decide on the balance of probabilities that for example the suspect knew the gun was loaded, possibly on the evidence provided by a witness, they assert their belief that the suspect knew 100% the gun was loaded. The judge in effect, decides that the suspect was at the time of the murder in the same position as he is himself at the time of the trial as to whether the gun was loaded, i.e. that the gun was loaded is regarded by the judge as a fact. Knowledge 100%. The judge would say himself that it would be a fact that the gun had been loaded. The judge would think he himself knew that fact. The assertion is always that you know 100%. That's what knowledge means.

Nobody ever says, "I know this for a fact" for no reason. Nobody says, "I know this but maybe it's not true", or "there's a probability I'm wrong". Later, you may accept you were wrong and that's why you need to revise your story from "I know" to "I didn't know". The claim to knowledge would have been wrong but that doesn't make knowledge less than 100%. It just means people assert their knowledge as 100% and later may accept they were wrong about knowing. You couldn't be wrong about knowing if it was less than 100%. That's how belief works. If you say you believe something, it definitely means you accept you may, or even just about might, be wrong. And if proven wrong later, you don't have to change the story from "I believe" to "I didn't believe" like you have to do when admitting you were wrong about knowing.
EB

 

[Speakpigeon]

It just happens that for a very long time we believed we knew the physical world. It's only recently, with science, that we have now more reasons to believe we now nothing about it.

Such as?

For example that we believe we are entirely biological organisms and that we can only interact with our environment through a perception system whose processes are entirely unconscious and therefore unknown to us except for the final representations we get within our mind of this environment. We know the representations, not what is represented. That's a fundamental fact about us. And whatever science we can do about our perception system cannot change this fact.
EB

Are you seriously under the impression that giving examples of things we can't know about the physical world qualifies as evidence we know nothing about it? That's illogical. You might as well try to prove man can never fly, because he has no wings, and try to prove it by presenting a list of wingless animals that can't fly.

This is getting painful to watch...

My example wasn't an example of "things we can't know about the physical world". It was an example of the evidence we have that we don't know things. It's an example of a good reason to believe we don't know and we can't know the physical world. You asked for evidence and when I give it to you, you just forget you asked for it and start on a tangente.
EB