Expanded Science

[lawcat]

That's fine. This point does not threaten Popper or the definition. It is simply a matter of the first step, whether the statement is valid. If I was sitting on some committee I would vote against your view. I don't think premature rejections are OK. But if it is the other way around, It's ok too. Eventually the truth will come out, even if it requires getting around this formality.

[Rade]

Let's consider the sentence: "Angels fly wingless."

 

OK, let us apply this statement to your criteria for what makes a statement scientific:

 

Science is a system of valid statements consistent with valid evidence

 

What I think you are saying is that "angels fly wingless" is a valid scientific statement for some proper branch of science, but not physics. The reasons being is that it can be falsified using valid evidence found in religious books that show pictures of angels flying, and that lots of animals fly, mostly with wings.

 

But, I see a problem--it has to do with the criterion of "valid evidence" as it must relate to your criterion of science. While it is true that science seeks truth, imo it seeks a limited type of truth, truth about the material universe. Why ? Because science must apply laws of nature and facts and theories derived from observation and experiment of nature judged against nature itself (the material universe). This is the reason I put "material universe" prior to "truth" in any valid definition of science.

 

So, while there is abundant scientific valid evidence for entities that fly and have wings where the laws of nature have been applied, I am not aware of a single published report of natural observation or experiment on an angel--I mean, not just how they fly--there is 0.0% valid evidence about angels derived from nature. To claim that there are artist paintings/drawings of imagined angels is not valid evidence of a scientific nature. Such artist productions are only valid evidence of a religious nature. Not a single artist in history has ever claimed that the drawing of any angel they made is from a material entity they observed in nature, or someone they attempted to talk to, perhaps serve tea to discuss how they enjoy working for God, etc.

 

Therefore, I conclude that the statement "angels fly wingless" is not a SCIENTIFIC statement of any kind--it is a statement outside of methods of science. It does not matter that the statement can be falsified using artist paintings--these do not represent "valid evidence" of scientific nature derived from observation of nature.

 

I think a key element of Popper is being missed to suggest that the statement "angels fly wingless" is a valid scientific statement. According to Popper, for a statement to be considered falsifiable via methods of science it must be "capable of observation or experiment". That is, for angels to be capable they must have been observed in nature either directly or indirectly (not only found as pictures in books), or have some logical/mathematical possibility of being observed (either directly or indirectly) in the future via the evidence of the senses. Clearly, flying is capable of observation, finding animals with wings or no wings is capable---BUT---observing angels in nature (with or without wings or legs or hands, etc.) is NOT a capable proposition.

 

Thus I conclude that I find nothing scientific about the statement "angels fly wingless" when I apply this criterion: Science is a system of valid statements consistent with valid evidence.

 

Perhaps this suggested modification will help clarify the type of valid evidence that is needed for a statement to be scientific:

 

Science is a system of valid statements about the material universe consistent with valid evidence.

[lawcat]

"Angels fly wingless" is imo a valid statment about material universe--it speaks directly to material universe. The problem with the statement is in the "evidence" as you put it. Evidence is not acceptable in physics. Moreover, the statement is irrelevant to physics because physics does not deal with angels. Whether angels fly wingless or not has no impact on anything in physics. Any finding on this topic would be a waste of time.

 

The requirement of material universe is concrete but unnecessary. Valid statements and valid evidence already covers it.

If your concern is that under the definition literature can be a science, then that is your physics bias. Physics is included in definition. Physicists should be ok with that. I don't see a reason for effort to appropriate word science to physics only. If that were the case, the definition would be simple. Science is physics or branches of physics--no need to complicate matters. Physics is a study of the universe. Done.

[jedaisoul]

Physics is a study of the universe.

No. Physics is what physicists define it to be. They define physics to be the study of the PHYSICAL universe.

 

Note: "Physical" is wider that "material". "Physical" includes material entities, electromagnetic phenomena and gravity. Oh, and anything else that physically exists, like anti-matter...

 

Also, what purpose does introducing your own definition of "physics" serve? Sounds dangerously close it ID to me.

[lawcat]

No. Physics is what physicists define it to be. They define physics to be the study of the PHYSICAL universe.

 

I agree with you. And this goes to the essence of the demarcation problem.

 

Can science be defined, and if it can, can physics be defined in such a way that it is distinguished from metaphysics (demarcation).

 

Two possible ways: 1) policy, leave it up to physicists, or 2) have a logically structured definition capable of inspection.

 

I think it can be defined logically, with ample room for policy for each field of study. Policy comes into play in methodology, deciding valid evidence, deciding valid statements.

 

As far as physical universe, biology is not physics, and biology is about physical universe. Or, living things are a part of physical universe, and physics is not about living things. So physics is only about parts of the physical universe? So condition of physical universe does not accurately cut it either, but it does get us closer.

 

And as far as ID, you are being funny. I've no interest in ID or arguing about it.

[Qfwfq]

I would agree that "god does not exist" is falsifiable, but "god does exist" would not usually be considered so. The latter is existential. I might put it this way: there are two physical possibilities, either god is observed or not. If god is observed then "god does not exist" is falsified. If God is not observed then "god does exists" is hardly falsified. Perhaps you just weren't in the right place and time to see God.

It's more subtle than that. Popper would not have considered either of the two falsifiable.

 

For one, although he often made a hash of things, he wasn't talking so much about statements as about theories. Those two statements are one the negation of the other, and therefore epistemologically equivalent. If one is known to be true, the other is consequently known to be false, and vice versa. Where would the essential difference between falsification and verification be?

 

What he meant was there being some conceivable empirical setup that, according to the theory in question, would be certain to give some outcome so that, failing this, the theory is falsified. You apply this to the "God does not exist." statement and conclude it is falsifiable but then you demonstrate that "God exista." isn't with an argument that shows the first isn't either: When you say that one might just not have been in the right place and time to see God, you imply that the test was not such as to make the outcome certain according to the "theory". As you implicitly uphold this for any test of the same statement you are stating that the only hope of observing God is to just happen on the right case for it. At that point, the eye witnesses can conclude that "God does not exist" is false; cosequently they also conclude that "God exists." is true, but they can only preach and others can believe or disbelieve them. That's hardly what he meant by a theory being scientific.

 

Apart from the above purely logical consideration, it is quite clear that those two statements are not really theories according to which an empirical test can really be excogitated. All those discussions about purely existential statements were just part of the whole entire argument about theories qualifying as scientific.

[Rade]

Let us look at four statements:

 

1. Angels fly wingless

2. The moon exists

3. God exists

4. Pigs fly with wings

 

So, which are scientific statements--statements that a scientist would consider valid for application of analysis by the scientific method. ? I suggest that only (2) and (4) are scientific statements, the other two are outside analysis by the scientific method. Now, I am not saying the other two cannot be debated and investigated, they can, they just cannot use the methods of science. Here I follow the definition of science provided by Lawcat:

 

Science is a system of valid statements consistent with valid evidence

 

According to Popper, for a statement to be scientific it must be CAPABLE of observation and/or experiment, either directly or indirectly. Thus, only capable statements contain completely valid evidence, non-capable statements contain at least some evidence that is not valid. I would add that this capability must be repeatable over time. I also add that the interaction between the subject and observer must be a two way interaction [entity x <--------> observer A].

 

For example, consider the past reported observations of angels by humans found in literature and religious books. In all known cases the interaction between the subject (angel) and observer (human) was subject controlled--the angel made itself known to the human. Present day humans that want to observe and/or experiment on a different set of angels than what is available find an impossible situation, they cannot proceed unless some angel initiates the interaction. Of course, the same can be said for God. For this reason, any statements that contain the word-concepts "angel" or "God" cannot be scientific, they fail the capability test because there is not a two-way interaction possible.

 

However, (pigs, moon, wings, flying) all are subjects completely open to present and future observation and/or experiment for humans. The observer is not limited to interactions with the moon or pigs found only in literature. New pigs are born each day. Likewise, a "new moon" or "full moon" occurs each month, completely different from any past month. A two-way interaction is present, that is, the moon and pigs and wings cannot decide they do not want to be observed. Of course the human observer can decide to observe or not observe.

 

I conclude that application of the above capability test will never fail to identify which statements are Popper scientific.

[jedaisoul]

The observer is not limited to interactions with the moon or pigs found only in literature. New pigs are born each day. Likewise, a "new moon" or "full moon" occurs each month, completely different from any past month. A two-way interaction is present, that is, the moon and pigs and wings cannot decide they do not want to be observed.

 

I conclude that application of the above capability test will never fail to identify which statements are Popper scientific.

I may have misunderstood, but it seems to me that there are many occurrences that do not fit your criterion of two-way interaction. Indeed almost any that are infrequent and occur at irregular intervals. What about the flowering of a plant that may flower only once in a hundred years or so? I can't just decide to observe the flowering of such a plant. I have to be in the right place at the right time, but it has to initiate the process by going into flower.

[modest]

I would agree that "god does not exist" is falsifiable, but "god does exist" would not usually be considered so. The latter is existential. I might put it this way: there are two physical possibilities, either god is observed or not. If god is observed then "god does not exist" is falsified. If God is not observed then "god does exists" is hardly falsified. Perhaps you just weren't in the right place and time to see God.

It's more subtle than that.

 

I could not agree more. I find it hard not to oversimplify when writing a concise post as well as reading an oversimplification into the posts of others. I think this is a very complicated issue that can be very easily distilled past its usefulness.

 

For one, although he often made a hash of things, he wasn't talking so much about statements as about theories.

 

While I might agree with you that there is a substantial distinction between a statement and a theory, Popper says explicitly otherwise. :shrug: Chapter 3 of TLoSD entitled "Theories" starts,

 

...Scientific theories are universal statements. Like all linguistic representations they are systems of signs or symbols. Thus I do not think it helpful to express the difference between universal theories and singular statements...

 

 

Those two statements are one the negation of the other, and therefore epistemologically equivalent.

 

I agree that they are one the negation of the other.

 

If one is known to be true, the other is consequently known to be false, and vice versa.

 

Agreed.

 

Where would the essential difference between falsification and verification be?

 

I'm not sure there would be any difference between falsifying "god exists" and verifying "god does not exist". As I said, I believe "God exists" is both non-falsifiable and verifiable. It should stand to reason that "God does not exist" is both falsifiable and non-verifiable. If one is unable to falsify "God exists" then they should be equally unable to verify "God does not exist".

 

Lawcat's other statement, "all angels fly wingless", seems to behave similarly. "All angels fly wingless" is both non-verifiable and falsifiable and "there exists an angel such that the angel does not fly wingless" is both verifiable and non-falsifiable.

 

In symbolic logic, let a be an angel and F(x) be the predicate "x flies wingless",

 

[math]\forall a | F(a)[/math]

(all angels fly wingless) is true if and only if F(a) is true of everything in the domain of a. There seems no practical way to check to whole domain meaning "all angels fly wingless" could not be verified. However, [math]\forall a | F(a)[/math] is false if F(a) is false for at least one member of the domain a. Finding a single counterexample is conceivable, so [math]\forall a | F(a)[/math] is falsifiable. The negation is,

[math]\exists a | \lnot F(a)[/math]

This is true if there is at least one in the domain a for which ~F(a) is true. Finding a single example is conceivable and therefore the statement is conceivably verifiable. The statement is false if and only if ~F(a) is false for the whole domain of a which again doesn't seem practically possible to check and therefore the statement considered non-falsifiable.

 

According to Popper, scientific laws are generally universal, of the form [math]\forall a | F(a)[/math], and therefore falsifiable but not verifiable.

 

That, I think, was his main criticism—no inductive method could truly verify a universal statement. Grossly oversimplified: no amount of corroboration truly verifies a scientific hypothesis, but a single counterexample can falsify it.

 

Apart from the above purely logical consideration, it is quite clear that those two statements are not really theories according to which an empirical test can really be excogitated. All those discussions about purely existential statements were just part of the whole entire argument about theories qualifying as scientific.

 

It seems possible that "god exists" and "god does not exist" are too simple or too controversial to be categorized concisely, but I don't believe I would be wrong in saying that Popper's system intended theories (or scientific laws) to be universal statements,

 

We can distinguish two kinds of universal synthetic statement: the 'strictly universal' and the 'numerically universal'. It is the strictly universal statements which I have had in mind so far when speaking of universal statements—of theories or natural laws...

 

...I consider it both useful and fruitful to regard natural laws as synthetic and strictly universal statements ('all statements'). This is to regard them as non-verifiable statements which can be put in the form: 'Of all points in space and time (or in all regions of space and time) it is true that...'

 

5.13, TLoSD

 

and purely existential ones to not be,

 

a simple, purely existential statement which is formulated in empirical terms... Clearly, this untestable theory is, in principle, verifiable... No observation in the world can establish its falsity.

 

appendix A, C&R

 

~modest

[Rade]

I may have misunderstood, but it seems to me that there are many occurrences that do not fit your criterion of two-way interaction. Indeed almost any that are infrequent and occur at irregular intervals. What about the flowering of a plant that may flower only once in a hundred years or so? I can't just decide to observe the flowering of such a plant. I have to be in the right place at the right time, but it has to initiate the process by going into flower.

Thanks for the comment. I would say let us apply the capability test to your question. So, suppose this statement:

 

1. Plant A flowers once every 100 years.

 

Is this a scientific statement, that is, is it capable of observation and/or experimentation ?

 

I would argue yes, for even if any one specific human observer may never have the ability to make the observation, the observation is capable by some human in the future. As I see it, when Popper indicates that statements of science are capable--he does not mean that they need be actual.

 

==

 

You raise an interesting question that I would like to discuss further.

 

So, which of these two statements below would be a scientific statement according to Popper, one, both, neither ? That is, which is based on valid evidence that is capable of observation and/or experiment ?

 

1. Plant A flowers once every 100 years.

2. Angels fly wingless

 

If we apply the capability test we reduce the situation to two word-concepts (1) plant A and (2) angels. Given that we have a concept for plant A such that we were able to make a statement about it, this must mean someone in the past observed plant A to flower (a chance event). Same logic for angels, someone must have made a claim of angel observation in the past and recorded it as text or picture. So, how does plant A differ from angel in terms of future potential for observation--or does it ? Suppose that each are only known from text or pictures from some past claim of human observation.

 

One logical difference must be that plant A is required by laws of nature to reappear in the future for potential observation (the reason being that a biological species cannot continue over time without reproduction), whereas an angel is not so required (angel appears via laws of God not nature and as far as is known angels have infinite life span). But you may argue, suppose that the past observation of the plant A was the last individual of its species and the ground where it grew is now a parking lot. Does this make statement (#1) non-scientific ? I think not, because the capability test is just that, the plant A recorded from the past must be viewed as being capable because the cause of its appearance derives from the laws of nature. In the same way potential energy is under no requirement to become actual, a capable observation has no requirement to become actual.

 

Thus, I would suggest that for situations of periodic appearance of some subject (plants that flower every 100 years, comets that become visible every 1000 years, angels, etc.), to determine if valid evidence is "capable", one must look to see if the future appearance of the subject is subject to some law of nature (reproduction, gravity, etc.), and not result from a "supernatural" cause.

[jedaisoul]

Thus, I would suggest that for situations of periodic appearance of some subject (plants that flower every 100 years, comets that become visible every 1000 years, angels, etc.), to determine if valid evidence is "capable", one must look to see if the future appearance of the subject is subject to some law of nature (reproduction, gravity, etc.), and not result from a "supernatural" cause.

What does "supernatural" mean? To me, it seems a meaningless term, because if the things attributed to it do actually exist, they are not supernatural! I.e. If angels actually existed, they would be race of winged hominids, which may, or may not, be able to fly (the classical illustrations of their wings are no way big enough to support a human body). But flightless birds do exist. So we need to distinguish between the entities (which may or my not be real), and the fanciful tales told about them. I.e. The fact that fanciful tales are told about something, does not make it "supernatural".

[Qfwfq]

I think this is a very complicated issue that can be very easily distilled past its usefulness.

Indeed. Perhaps you mean it about my argument, but I think Popper's overall argument about demarcation runs this risk.

 

I must say I did a lousy job on my last post here, at the end of a weary day, indeed I wasn't satisfied with my post even when I hit the submit button. Later I regretted having made that statement of what Popper would think, instead of saying it would be mistken to conclude it from his work, but I wasn't quite aware of:

Popper says explicitly otherwise.

Yeah, Popper says! :evil:

 

There are certainly many details of his work that I just can't agree with and you have just shown me another one. I have read C&R but not L. Sc. D. :doh: However, I found him not being perfectly self consistent between different works which are gathered into C&R so I wouldn't rely on him being so between it and L. Sc. D. and I really didn't think he could have missed the obvious logic that I (so badly) illustrated in my previous post.

 

I'm not sure there would be any difference between falsifying "god exists" and verifying "god does not exist".

Certainly no difference; this was quite part of my point. The fact is that one is the negation of the other. I would expect Popper was aware that the negation of a statement of the one category is of the other. If, for any statement A and its negation, he meant that one should pass demarcation and the other fail it, then he needed his head examined.

 

I would not seriously call "Not every swan is white." pseudoscientific when we even know it already has turned out to be true. Would you call "The Loch Ness monster exists." pseudoscientific? You would have to declare it would continue to be so, even after someone caught a specimen and put in the Inverness Zoo, since his demarcation problem is about logic and not about fact.

 

No point arguing about whether angels fly wingless because... it's a known fact! Those wings in Christian iconography, which appeared after the first few centuries, were meant as purely symbolic, but don't tell people today :zip: cuz so many folks take them literally. :D

Your logic is absolutely fine there, :) just I don't see the point of spelling it out when there's no doubt about it.

 

According to Popper, scientific laws are generally universal, of the form [math]\forall a | F(a)[/math], and therefore falsifiable but not verifiable.

There exist choices of coordinates which are inertial. For each space-time point, there exist choices of coordinates which are locally inertial. The second example has the required [math]\forall[/math] in it but, once a point is chosen, one is left with a dreadful [math]\exists[/math] statement, which itself is verifiable but not falsifiable. So the complete statement is neither. Is it pseudoscientific? Even if you were right at that point of space-time which de facto falsifies it, how could you refute the Ansatz of general relativity? Despite this, Eddington's observation might in principle have refuted the theory.

 

That, I think, was his main criticism—no inductive method could truly verify a universal statement.

It was well know for a while before Popper. The problem was that Bacon's recipe, which typically caused essentially inductivisapproaches, had become fairly prominent and upheld much more widely than Galileo's more balanced prescriptions; many consider he was quite aware of the importance of there being no logical consequences that conflict with fact, as well as the main ones matching up with fact. He quoted Aristotle as saying this and ridiculed some medieval Peripatetics who even denied new empirical facts because they contradicted some opinion of their revered teacher. Bacon never pointed this out, then again he wasn't actually a natural philosopher.

 

It seems possible that "god exists" and "god does not exist" are too simple or too controversial to be categorized concisely, but...

I don't think this makes any difference, provided we argue over epistemology and not theology. The swan example is logically equivalent. So is the Loch Ness monster, or the Yeti.

 

I don't believe I would be wrong in saying that Popper's system intended theories (or scientific laws) to be universal statements,

 

..........

 

and purely existential ones to not be,

Yes I'm aware of him arguing along these lines, he says these thing backwards and forwards and inside out, all through his work. But I can't agree with the idea of applying his falsifiability criterion to single bare propositions.

 

A "natural law" is not the same thing as what I call "a theory" no matter what terms Popper used. Hack, he wasn't a scientist and I find him having a great interest in it and knowledge of many scientific facts but also some confusion about the process. I think he could have argued against inductivism in a better way.

[Rade]

No point arguing about whether angels fly wingless because... it's a known fact!

Seems to me there is a difference between a man-made fact and a metaphysical fact. The statement "angels fly wingless" is a man-made statement of a "fact" that cannot be evaluated using Popper criteria. A statement using a man-made fact does not have to be necessary, it may be otherwise. Conversely, the statement "pigs do not fly with wings" is a statement of a metaphysical fact, it is a statement that cannot be otherwise, it is a necessary statement of a fact.

[Rade]

What does "supernatural" mean? To me, it seems a meaningless term, because if the things attributed to it do actually exist, they are not supernatural!

A fair question, of course all concepts such as "supernatural" must come with a definition.

 

To attempt an answer to your question, I think we can agree that something must exist in the universe, and of those things that do exist, we can logically divide them into: (1) those that exist by causes of "nature" and (2) those that exist by causes outside of nature = "supernatural". To exist by "nature" I mean that the thing in question is capable of becoming and ending, that is, things caused by nature are capable of transforming from existence to non-existence. Please let me know if you disagree with any of the above.

 

We were discussing angels, pigs, moon, wings as things that "actually exist" that we may wish to put into a statement to determine if the statement meets the "scientific" criterion of Popper. Three of the terms (pigs, moon, wings) exist via cause(s) of "nature" and are capable of perishable, one exists by cause outside of nature and has infinite existence (angel) and is thus classified as a "supernatural" thing that exists.

[modest]

I think this is a very complicated issue that can be very easily distilled past its usefulness.

Indeed. Perhaps you mean it about my argument, but I think Popper's overall argument about demarcation runs this risk.

No, I didn't mean about your argument and certainly not about Popper, but rather my own summary of his work.

 

Later I regretted having made that statement of what Popper would think, instead of saying it would be mistken to conclude it from his work, but I wasn't quite aware of:

Popper says explicitly otherwise.

I had suspected that, which is why I added "While I might agree with you that there is a substantial distinction between a statement and a theory..."

 

Nonetheless, conversation in the thread had turned to whether or not specific statements were falsifiable, and I think that's a worthy thing to consider.

 

I'm not sure there would be any difference between falsifying "god exists" and verifying "god does not exist".

Certainly no difference; this was quite part of my point. The fact is that one is the negation of the other. I would expect Popper was aware that the negation of a statement of the one category is of the other.

 

Yes, he certainly did know,

 

The negation of a strictly universal statement is always equivalent to a strictly existential statement and vice versa. For example, 'not all ravens are black' says the same thing as 'there exists a raven which is not black', or 'there are non-black ravens'.

 

The theories of natural science, and especially what we call natural laws, have the logical form of strictly universal statements; thus they can be expressed in the form of negations of strictly existential statements or, as we may say, in the form of non-existence statements (or 'there is-not' statements). For example, the law of conservation of energy can be expressed in the form: 'There is no perpetual motion machine'... and it is precisely because they do this that they are falsifiable...

 

...Strictly existential statements, by contrast, cannot be falsified. No singular statement (that is to say, no 'basic statement', no statement of an observed event) can contradict the existential statement, 'There are white ravens'. Only a universal statement could do this...

 

3.15 TLoSD

 

If, for any statement A and its negation, he meant that one should pass demarcation and the other fail it, then he needed his head examined.

 

I don't understand why. You've brought it up twice like an objection, but I don't understand exactly what it is you're objecting to. This seems consistent to me:

 

I'm not sure there would be any difference between falsifying "god exists" and verifying "god does not exist". As I said, I believe "God exists" is both non-falsifiable and verifiable. It should stand to reason that "God does not exist" is both falsifiable and non-verifiable. If one is unable to falsify "God exists" then they should be equally unable to verify "God does not exist".

 

The one is the negation of the other, the one falsifiable and the other verifiable.

 

I would not seriously call "Not every swan is white." pseudoscientific when we even know it already has turned out to be true. Would you call "The Loch Ness monster exists." pseudoscientific?

 

I would call the first scientific and the latter pseudoscientific.

 

Both statements are non-falsifiable. They are both, as I'm sure you know, purely existential,

• There exists a swan such that the swan is not white
  
• There exists a monster such that its name is Loch Ness
  

In chapter 3 of TLoSD Popper talks about two kinds of statements important to science. From the second paragraph of section 12:

We have thus two different kinds of statement, both of which are necessary ingredients of a complete causal explanation. They are (1) universal statements i.e. hypotheses of the character of natural laws, and (2) singular statements, which apply to the specific event in question and which I shall call 'initial conditions'.

He goes on to explain why the distinction is important and also that 'singular statements' are often existential having to do with predictions of theories.

 

Clearly the two examples you give are of type (2). The reason, I believe, that statement 1 is scientific while statement 2 is not is because the former is a confirmed prediction of a scientific theory. Biology explains, for example, that the offspring of two black swans will be born black. Biologists can predict when, where, and how it will happen.

 

The same cannot be said of "There exists a monster such that its name is Loch Ness". It is not, as far as I know, a confirmed prediction of any falsifiable theory. The example I have offhand of Popper saying something similar is the Neutrino statement:

 

Whenever a pure existential statement, by being empirically confirmed, appears to belong to empirical science, it will in fact do so not on its own account, but

by virtue of being a consequence of a corroborated falsifiable theory

. Thus the discovery of the neutrino... not only confirmed the until-then metaphysical assertion ‘For every beta emission there is a neutrino emitted from the same nucleus’; it also provided a test of the much more significant

falsifiable

theory that such emitted neutrinos could be trapped in a certain way. [his emphasis.]

 

Rethinking Popper

 

I don't think all purely existential statements are excluded from science just because they are non-falsifiable. Rather, they need to be a confirmed part (or prediction) of a falsifiable theory. It is not enough that someone returns to England from Australia saying "I found a black swan". Nor would a picture or an eye witness account of Loch Ness necessarily make her part of science.

 

You would have to declare it would continue to be so, even after someone caught a specimen and put in the Inverness Zoo, since his demarcation problem is about logic and not about fact.

 

Right. I would contend that "there exists a swan such that the swan is not white" continues to be non-falsifiable even after it is confirmed. Its logical structure makes it so. Therefore, if the empirical sciences contained only falsifiable statements then it would be forever stricken from science (confirmed or not). As I said in my first post in this thread, I don't think that was Popper's intent.

 

In fact, I'm just reading more of the chapter and let me quote from a footnote,

 

The word 'isolated' has been inserted to avoid misinterpretation of the passage though its tendency, I feel, was clear enough: an isolated existential statement is never falsifiable; but if taken in context with other statements, an existential statement may in some cases add to the empirical content of the whole context: It may enrich the theory to which it belongs, and may add to its degree of falsifiability or testability. In this case, the theoretical system including the existential statement in question is to be described as scientific rather than metaphysical.

 

No point arguing about whether angels fly wingless because... it's a known fact! Those wings in Christian iconography, which appeared after the first few centuries, were meant as purely symbolic, but don't tell people today :zip: cuz so many folks take them literally. :D

 

:hihi:

 

According to Popper, scientific laws are generally universal, of the form [math]\forall a | F(a)[/math], and therefore falsifiable but not verifiable.

There exist choices of coordinates which are inertial. For each space-time point, there exist choices of coordinates which are locally inertial. The second example has the required [math]\forall[/math] in it but, once a point is chosen, one is left with a dreadful [math]\exists[/math] statement, which itself is verifiable but not falsifiable. So the complete statement is neither.

 

I see what you're saying. I believe the second statement could be considered universal by Popper's system even though the second half is existential. It's not unlike the example he gave of a universal law, "For every thread of a given structure S (determined by its material, thickness, etc.) there is a characteristic weight w, such that the thread will break if any weight exceeding w is suspended from it."

 

The "there exist choices of coordinates..." or "there is a characteristic weight..." part doesn't seem to detract.

 

Is it pseudoscientific? Even if you were right at that point of space-time which de facto falsifies it, how could you refute the Ansatz of general relativity? Despite this, Eddington's observation might in principle have refuted the theory.

 

While I think the equivalence principle is probably a universal statement, I don't think it would be a problem for a postulate of a theory to be non-falsifiable in Popper's system. The system gives 4 criteria for the postulates of a theory, none of which that they are falsifiable or universal in section 16 of TLoSD.

 

I'd call GR universal because the Einstein equation is universal. Eddington, like any other test, is potentially fatal to the theory.

 

~modest

[Qfwfq]

So what are we arguing over, then? It now seems that both you and Popper agree that the falsifiability criterion should not be just blindly applied to the single propositions, but instead to a theory. Except that, you still keep suggesting otherwise too...

 

I don't understand why.

It seems clear to me. I'm not talking about which is falsifiable and which is verifiable. I'm saying it doesn't make sense to apply the demarcation criterion to each single statement. You keep translating the latter into the former, yet it now seems even Popper wasn't so totally confused about this.

 

I would call the first scientific and the latter pseudoscientific.

Errr...

I don't think all purely existential statements are excluded from science just because they are non-falsifiable. Rather, they need to be a confirmed part (or prediction) of a falsifiable theory. It is not enough that someone returns to England from Australia saying "I found a black swan". Nor would a picture or an eye witness account of Loch Ness necessarily make her part of science.

I wasn't claiming these would be enough, despite the fact that not everybody has performed certain experiments and observations, especially those which can't be done whenever one chooses. My conjecture was the future availabilty of specimens of Nessie for any biologist to examin, as has long been so for Australian black swans. One of Popper's points was that it was foolish to rule out the possibility of a black swan before they were seen and I don't see grounds for your distinction about this being the prediction of a scientific theory; there were no theoretical grounds to rule them out, nor to predict them. Your point about biology, explaining that the offspring of two black swans will be born black, is just begging the question; if they exist, then it follows that they exist.

 

There are varying degrees of necessity for confidence or trust in a reliable or reputed source. Solar eclipses come frequent enough (though it is still more often that one can go looking for the Yeti if one so chooses) but how often can you observe a supernova? How many particle physicists have run all the important experiments at CERN, SLAC or DESY themselves, for instance? But many people scoff at the Yeti while the Sherpa say their ancestors always had to protect their livestock from them and they are currently confident of having killed the last ones; they are talking about their subsistence so I doubt they're just in the mood for a hoax. If they really have killed the last of them, great pity for biologists eh?

 

Now I disagree with Popper's use of terms when he talks about a "metaphysical theory" becoming science, such as the neutrino example; it was a conjecture and it since turned out to be a fact. Nessie and the Yeti are metaphysical theories? Naaaah, I'd call them conjectures too and there were damn good grounds for the neutrino conjecture. Just recently I read that Fermi had initially submitted his paper to Nature and it was rejected because "it contained speculations which were too remote from reality" despite the conjecture being due to energy-momentum conservation; go figure.

 

If physicists had simply said OK, beta decay falsifies energy-momentum conservation, then the neutrino would be a more far fetched idea even than Nessie, with much less chance of Tom, Dick or Harry just happening to catch a glimpse of it during a morning walk along the banks.

 

As I said in my first post in this thread, I don't think that was Popper's intent.

So I don't get why you seemed to be contradicting me on this, more recently. :shrug:

 

The "there exist choices of coordinates..." or "there is a characteristic weight..." part doesn't seem to detract.

How would you falsify the statement itself when, for any case in which you haven't verified the second clause, you can't assert to having falsified it for that case?

 

GR is falsifiable. So is the equivalence principle, regardless of the field equation, but you couldn't do it according to the logical structure of that statement, just as it is. You can only falsify it through a necessary consequence, by finding two bodies that are subject to different acceleration at the same point. This of course is because it is translatable into the "All bodies fall equally." form.

[modest]

So what are we arguing over, then?

 

I'm not sure we're arguing, but I disagreed strongly, and continue to disagree strongly, with these statements:

 

a) Statement

- True or false requirement signifies falsifiability, the sentence must be capable of existing in true or negated form. For example, "God does exist" is a statement. It is a statement because it can be in true or false form--it is falsifiable. The negated version of that statement is "God does not exist." Therefore, the statement "God exists" is falsifiable. "God does not exist" is also falsifiable by "God does exist," and is therefore a statement. Both are falsifiable statements.

 

 

Popper would not have considered either of the two falsifiable.

 

My position is simply that "god exists" is purely existential and non-falsifiable. "god does not exist" is universal and falsifiable. I believe the quotes I've given show Popper to be in agreement.

 

~modest