Popper and Falsification(ism)

[Sparky56]

[MOD NOTE: This thread was created by splitting the posts discussing Sparky56's contentions re Popper and falsification(ism), from the How open-minded in mainstream science? thread.

While I have tried to move only the relevant posts, there are a few which I may have missed, and a few which should perhaps not have been moved.]

A better formulation would be "A theory, if falsified, cannot be considered valid."

Utter drivel. The point is that for a theory to be scientific (testable), then it must be falsifiable. The three terms are synonymous, for the umpteenth time.

Of course, once a theory has been falsified it is no longer valid, but this not a reformulation ... it is a statement of the obvious.

Yes, this is a very technical point.

No, it's very basic. No theory should be considered invulnerable.

But don't take my word for it. Popper's book, The Logic of Scientific Discovery, lays down his methodology in great detail. However, it is very technical. As an introduction I would recommend Brian MaGee's imaginatively titled 'Popper', Fontana/Collins, 1973. To quote from the book:

P29: "...Popper realized that no theory could be relied upon to provide the final truth."

P39: "Falsification in whole or part is the anticipated fate of any genuinely scientific theory. Nothing in science is permanently established."

P43: "...so a genuinely scientific theory places itself permanently at risk."

The philosophy known as Logical Positivism relied on facts rather than theories. Popper effectively destroyed it.

The other day I found an old thread about this topic by someone called Superdragon, but I can't find it now. He demonstrated far more patience than I am prepared to lavish.

[Grey]

Utter drivel. The point is that for a theory to be scientific (testable), then it must be falsifiable. The three terms are synonymous, for the umpteenth time.

I think everyone agrees with this. The thing that folks were taking issue with was your concluding from this that any theory can only be valid for a finite time. Being falsifiable means that a theory could, in principle, be shown to be false by some experiment. That really just means that the theory makes definite predictions for the outcomes of experiments that we can perform to check whether those predictions hold. However, whether or not it will be shown false depends on whether or not it actually is false.

Now, it's possible to think that it's not possible for any theory to be any better than an approximation of the laws of nature, and that we'll continue to develop ever better approximations, but never get to a final description. If that's true, then any theory will indeed eventually be supplanted, at least as long as you assume science will continue to progress. However, I don't think that's a foregone conclusion, and it's equally possible to imagine that we might be able to come up with a theory that is, in fact, perfectly correct.

Now, hold on a second before you object. That doesn't mean that such a theory is unfalsifiable. In fact, as far as we would know, it would be just as capable of being shown false as any other theory. We'd never actually be able to know that this theory is perfectly correct. It would remain forever vulnerable, in principle, to being falsified by the right experiment. It's just that no attempts to do so would succeed.

Do you see the difference here? A theory is falsifiable as long as it makes predictions that can be tested. However, if every such test turns out to confirm the theory, then it will never be falsified, and it would not have a finite lifetime. We'll never know for sure that the next test won't show it be false, and we'll keep trying, but we might never succeed in showing it to be false, even though it remains always theoretically possible to do so.

[Van Rijn]

A better formulation would be "A theory, if falsified, cannot be considered valid."

Utter drivel. The point is that for a theory to be scientific (testable), then it must be falsifiable. The three terms are synonymous, for the umpteenth time.

Of course, a theory must be falsifiable, as I said. For the umpteenth time, that isn't the issue in debate. The issue is with statements like these (bolding added):

As a logical consequence of this, a theory is only valid until it is falsified, that is for a finite time.

A theory can only be conclusivley falsified, ie., disproved, but never conclusively verified (proved), as all scientific theories, by definition, are vulnerable to being falsififed, and are therefore only valid for a finite time.

The point in contention is your assumption that there must be a time limit on theories.

No, it's very basic. No theory should be considered invulnerable.

Please point out where anyone said they should be. Whether a theory is falsified depends on discoveries and logic. It does not depend on time. A theory is always potentially falsifiable. There is no time limit on when or whether it will be falsified.

Ok, Sparky? If you are going to argue, then at least argue the point. Please demonstrate where time applies in the argument.

[Sparky56]

The point in contention is your assumption that there must be a time limit on theories.

This is not my assumption. It is a logical and unavoidable consequence of the rigid philosophical methodology known as Falsificationism.

A common misconception relates to corroboration.
http://plato.stanford.edu/entries/popper/#Dema

"It is easy, he argues [Popper], to obtain evidence in favour of virtually any theory, and he consequently holds that such ‘corroboration’, as he terms it, should count scientifically only if it is the positive result of a genuinely ‘risky’ prediction, which might conceivably have been false. For Popper, a theory is scientific only if it is refutable by a conceivable event. Every genuine test of a scientific theory, then, is logically an attempt to refute or to falsify it, and one genuine counter-instance falsifies the whole theory."

It is very important to understand that Popper conceived this criterion of demarcation to overcome the 'Problem of Induction'. It is essential to understand this before you can grasp the essence of Falsifiability.

Until you can demonstrate an understanidng of this, I am not prepared to debate with you.

"In a critical sense, Popper's theory of demarcation is based upon his perception of the logical asymmetry which holds between verification and falsification: it is logically impossible to conclusively verify a universal proposition by reference to experience (as Hume saw clearly), but a single counter-instance conclusively falsifies the corresponding universal law. In a word, an exception, far from ‘proving’ a rule, conclusively refutes it."

If you disagree with me, then your argument lies with Popper and his methodology, not with me. My account is an accurate representation.

Edit: Quotes coloured.

[Sparky56]

Do you see the difference here?

No.

A theory is falsifiable as long as it makes predictions that can be tested.

Yes. Testable == Falsifiable == Scientific.

However, if every such test turns out to confirm the theory, then it will never be falsified, and it would not have a finite lifetime.

OK, I can see where you are coming from. While you are not exactly wrong, you are not right, at least according to the method.

We'll never know for sure that the next test won't show it be false, and we'll keep trying, but we might never succeed in showing it to be false, even though it remains always theoretically possible to do so.

Again, it helps to see things the other way around, that is, from a Popperian perspective.

The opposite of false in this methodology in not true, but verified or corroborated, because scientific theories can only be conclusively falsified (proved wrong) and not conclusively verified (proved true). In other words, proof exists only in the negative!

The 'Problem of Induction' relates to numerous supporting instances which seem to prove a theory. Popper turns this on its head. Falsifiablity dictates (yes, dictates) that no number of supporting instances can guarantee the truthfulness of a theory. The method assumes that it will falsified at some point in time, by virtue of continually demanding challenging-tests, and not merely corroborating events.

Again, you may not be happy with this implication of the method. But too bad. This is how it is. I say again, if you disagree with me, then your argument lies with Popper and his methodology, not me.

[TheBlackCat]

Again, you may not be happy with this implication of the method. But too bad. This is how it is. I say again, if you disagree with me, then your argument lies with Popper and his methodology, not me.

NOBODY HAS NY PROBLEMS WITH THE IMPLICATIONS OF THIS METHOD

The issue isn't whether it can be falsified, the issue is whether it will be falsified. The method you are talking about, as people have said over and over and over and over again, says that all theories can potentially be falsified. Nobody in this topic disagrees with that, as they keep saying. The question is whether the will be falsified. The information you have posted does NOT say it "all theories will eventually be falsified", it says "all theories can eventually be falsified". This is a major difference. The fact that something is possible does not mean it will necessarily happen. If a theory is right, it will never be falsified. We can never know this for sure, and tests trying to falsify it will always be done. The potential for it to be falsified will always exist, but the actual event of falsification will never occur. There is a big difference between an event being conceivable and an event actually occuring. The fact that an event is concievable does not automatically mean it will happen.

You are taking a universally accepted component of scientific inquiry and taking an unwarranted and illogical leap in order to make a statement that is simply not part of the method. You are reading implications into the scientific method that are simply not there.

[Grey]

Do you see the difference here?

No.

Okay, then let's try it again. Everyone here agrees that, under Popper's methodology, a scientific theory is testable or falsifiable by definition. Quoting from your source, "For Popper, a theory is scientific only if it is refutable by a conceivable event." Do you really not see the difference between a theory being refutable by some conceivable event, and a theory being refuted by some specific test? In the former case, we simply imagine some experiment which could have an outcome showing the theory to be wrong. In the latter case, we've actually done some experiment, and come up with a real observation that is incompatible with the theory. Now do you see the difference?

OK, I can see where you are coming from. While you are not exactly wrong, you are not right, at least according to the method.

Aha! Light! At least maybe...

Again, it helps to see things the other way around, that is, from a Popperian perspective.

The opposite of false in this methodology in not true, but verified or corroborated, because scientific theories can only be conclusively falsified (proved wrong) and not conclusively verified (proved true). In other words, proof exists only in the negative!

Of course. Nobody here is arguing that one can prove something true, at least from a Popperian perspective. The only thing under contention is that, although any theory should be vulnerable to being proved false in principle, it is conceivable that this might never happen for some theory, in spite of all attempts to do so. That would not prove such a theory true (and nobody is claiming that it would), merely that it has not yet been proven false. And although we might always be able to imagine some new test that would invalidate the theory, it might happen that no such test actually does invalidate it.

The method assumes that it will falsified at some point in time, by virtue of continually demanding challenging-tests, and not merely corroborating events.

Nope, this is where you've departed from Popper. That a theory could be falsified by some conceivable experiment does not lead logically to the conclusion that it will be falsified by some actual experiment. I don't believe you can find a direct quote from any of Popper's works claiming that the latter must be true.

[TheBlackCat]

You apparently didn't actually read your own link very well, sparky. From the website you posted:

Every genuine scientific theory then, in Popper's view, is prohibitive, in the sense that it forbids, by implication, particular events or occurrences. As such it can be tested and falsified, but never logically verified. Thus Popper stresses that it should not be inferred from the fact that a theory has withstood the most rigorous testing, for however long a period of time, that it has been verified; rather we should recognise that such a theory has received a high measure of corroboration. and may be provisionally retained as the best available theory until it is finally falsified (if indeed it is ever falsified), and/or is superseded by a better theory.

(emphasis added) They explicitly say, in the link that you are using as evidence to support your position, that it is possible for some theories to never be falsified.

[Disinfo Agent]

Last time Sparky was here, he ended up running away and leaving lots of questions unanswered. I suggest that he should answer those questions before we pay him any further attention.

[worzel]

Come off it Sparky! Over 100 posts ago you said "all scientific theories, by definition, are vulnerable to being falsififed, and are therefore only valid for a finite time." and I pointed out the obvious logical flaw in that statement. How many other poeple here, in your humble opinion, need to reread (or even read in my case) Popper so they can reach your level of enlightenment and realise that "falisifiable" = "false"

[Sparky56]

How many other poeple here, in your humble opinion, need to reread (or even read in my case) Popper so they can reach your level of enlightenment and realise that "falisifiable" = "false"

No one is saying that falsifiable == false, are they? I most certainly am not.

Popper said that falsification was the anticipated fate of all scientific theories. That is a quite a different thing.

I note that no one has picked up on why Popper conceived this method in order to overcome the 'Problem of Induction'. This is a central issue.

From the linked page:

Every genuine scientific theory then, in Popper's view, is prohibitive, in the sense that it forbids, by implication, particular events or occurrences. As such it can be tested and falsified, but never logically verified. Thus Popper stresses that it should not be inferred from the fact that a theory has withstood the most rigorous testing, for however long a period of time, that it has been verified; rather we should recognise that such a theory has received a high measure of corroboration. and may be provisionally retained as the best available theory until it is finally falsified (if indeed it is ever falsified), and/or is superseded by a better theory.

I agree with my bold, above -- "provisionally retained as the best available theory until it is finally falsified" -- as the following is superfluous, and misleading. It certainly contradicts the preceding.

I will leave the final word to Popper, when he summed up Falsificationism, thus:

"Our knowledge can only be finite, while our ignorance must necessarily be infinite."

[worzel]

No one is saying that falsifiable == false, are they? I most certainly am not.

You most certainly are; because if, as you claim, every theory must, of necessity, be falsifified eventually, then every theory must be false irrespective of when they are falsified. [ EDIT: I suppose it would be more accurate to sum up your position as falsifiable theory => false theory ]

Popper said that falsification was the anticipated fate of all scientific theories. That is a quite a different thing.

"Anticipated fate" is quite a different thing to "necessary fate".

I note that no one has picked up on why Popper conceived this method in order to overcome the 'Problem of Induction'. This is a central issue.

I note that you are stil trying to broaden the discussion to avoid the issue, which is that your claim that all scientific theories are necessarily false due to their falsifiability is false.

[worzel]

From the linked page:

Every genuine scientific theory then, in Popper's view, is prohibitive, in the sense that it forbids, by implication, particular events or occurrences. As such it can be tested and falsified, but never logically verified. Thus Popper stresses that it should not be inferred from the fact that a theory has withstood the most rigorous testing, for however long a period of time, that it has been verified; rather we should recognise that such a theory has received a high measure of corroboration. and may be provisionally retained as the best available theory until it is finally falsified (if indeed it is ever falsified), and/or is superseded by a better theory.

I agree with my bold, above -- "provisionally retained as the best available theory until it is finally falsified" -- as the following is superfluous, and misleading. It certainly contradicts the preceding.

The following clarifies your bold, because although it may be anticipated that every theory will eventually be falsified, it is not logically necessary (be they false or not).

[TheBlackCat]

I agree with my bold, above -- "provisionally retained as the best available theory until it is finally falsified" -- as the following is superfluous, and misleading. It certainly contradicts the preceding.

It is not the least bit contradictory and is certainly not superfluous in the current discussion. It is simply directly refuting your entire argument. It is not contradicting the preceding, it is qualifying and clarifying the preceding to show that it is not always the case. That is exactly what we have been saying all along, you can't just dismiss that out of hand because it goes against your views. And you certainly can't claim the statement is contradictory, it is fully self-consistent if you read the whole sentence. It is only contradictory if you read the first part, assume it is always the case (which is not claimed once in the entire article), then refuse to change your interpretation of the sentence when you read the whole thing and find out what the author is really saying. If you read it as a whole statement it is perfectly consistent and not the least bit misleading. I would agree it is superfluous in normal usage, the statement is common sense and I do not think it would occur to any scientist that the situation is any different than as it is stated there.

You give us a link that you claim supports your position. When someone actually bothers to check the link, they find that it directly goes against your position. So in response you choose to dismiss the parts of the link that go against your position as "superfluous" and only accept those parts that agree with your position. Your evidence falsifies your position, if you choose to only take the bits of the evidence that agree with you and ignore all the rest you are going against the scientific method you claim to respect so highly.

And that quote by Popper no more supports your position than any of the other evidence you have provided.

[worzel]

Your evidence falsifies your position, if you choose to only take the bits of the evidence that agree with you and ignore all the rest you are going against the scientific method you claim to respect so highly.

But the science here is interpreting-Popper-ology, which is just philosophy (yawn) anyway

[Sparky56]

I suppose it would be more accurate to sum up your position as falsifiable theory => false theory

Nonsense!

"Anticipated fate" is quite a different thing to "necessary fate".

What?

Popper said that 'falsification is the anticipated fate of all scientific theories', and also that 'because a theory is false does not mean it cannot have verisimilitude.'

Whether or not I agree with him is a different matter, I am merely explaining the logical consequences of this methodology.

"Our knowledge can only be finite, while our ignorance must necessarily be infinite." Karl Popper

The above is the very foundation and essence of this philosophical methodology. There is no escape from this fact!

[Sparky56]

But the science here is interpreting-Popper-ology, which is just philosophy (yawn) anyway

Really?

[Sparky56]

And that quote by Popper no more supports your position than any of the other evidence you have provided.

I assume you mean this one:

"Our knowledge can only be finite, while our ignorance must necessarily be infinite." Karl Popper

We are not dealing with evidence (my bold in your quote above) in any empirical sense, but the application of a philosophical methodology in a logical and consistent sense. Big difference.

For example, you can falsify a scientific theory, but you cannot falsify Falsificationism, as it is not a theory, rather a methodology.

You can construct arguments against it. Fine. Feel free to do so. I am merely explaining the logical consequences of the method, which are are adequately summarised in the boldened quote above, from the man himself.

[TheBlackCat]

We are not discussing falsification. We are discussing your opinion of the implications of falsification. You make a statement regarding the implications of falsification. You give evidence to support yout opinion of the implications. But the evidence you give directly refutes your opinion. So you dismiss those parts of the evidence that go against your opinion. I understand that this is not an emprical, scientific issue, but for someone who claims to have such high opinion of the scientific method and falsification you sure don't seem to want to follow the spirit of the idea when it is applied to your own arguments.

And nobody here is debating falsifiction. Stop saying that, it is wrong and is nothing but a strawman argument you are using to make everyone else look foolish. We are debating your opinion of the implications of falsification, which is something completely different. You are claiming your opinion is the "logical consequences of the theory", we are claiming it is not. Surely you must understand that you are making an interpretation of falsification, right? What seem like "logical consequences" do not seem tht logical to us, or the author you cited, so surely you must see that it is your opinion, right?

[worzel]

I suppose it would be more accurate to sum up your position as falsifiable theory => false theory

Nonsense!

Well you got me there, I'm always a sucker for a well reasoned argument. Look, you have claimed that every falsifiable theory has a finite time until it is falisified - that is equivalent to saying that every falsifiable theory is false. Unless, that is, you believe that the actual (as opposed to known) laws of physics change when a theory is falsified - is that what you believe?

"Anticipated fate" is quite a different thing to "necessary fate".

What?

Popper said that 'falsification is the anticipated fate of all scientific theories',

I might anticipate rain by taking an umbrella, that does not mean it will necessarily rain.

and also that 'because a theory is false does not mean it cannot have verisimilitude.'

Obviously, but we're talking about theories that we don't know are false (i.e. they haven't been falsified).

Whether or not I agree with him is a different matter, I am merely explaining the logical consequences of this methodology.

No you're not. You're making an illogical leap from falsifiable to necessarily false by claiming that every scientific theory will be falsified within a finte amount of time.

"Our knowledge can only be finite, while our ignorance must necessarily be infinite." Karl Popper

The above is the very foundation and essence of this philosophical methodology. There is no escape from this fact!

It is ironic that you keep quoting that because, whether you realise it or not, you are claiming that we can be certain that all falsifiable theories are false whereas the truth is that while we can never know that a theory is true, until a theory is falsified we cannot even be sure that it is false.

[Sparky56]

This brings us full circle. Consider this premise of Falsificationism:

"No scientific theory can be conclusively verified, only conclusively falsified."

A logical consequence of which is, to quote Popper:

"Our knowledge can only be finite, while our ignorance must necessarily be infinite."

Hehe

This is not my interpretation -- and I do not necessarily agree with the implications -- but this is how it is, at least according to the methodology!

[worzel]

This brings us full circle. Consider this premise of Falsificationism:

"No scientific theory can be conclusively verified, only conclusively falsified."

A logical consequence of which is, to quote Popper:

"Our knowledge can only be finite, while our ignorance must necessarily be infinite."

Hehe

This is not my interpretation -- and I do not necessarily agree with the implications -- but this is how it is, at least according to the methodology!

Dance around all you like, Sparky, nothing you quoted says (or implies) that we can be sure that a theory is false ahead of falsifying it. All we can be sure of is that a theory is falisfiable and that is has been falsified when and if that occurs. Again, you miss the irony of the last sentence you quote. You are claiming we have more certainty than we do in saying that we can be sure that all falsifiable theories are false. You conveniently ignored the point I made that while we can never know that a theory is true, until a theory is falsified we cannot even be sure that it is false.

I'm off to bed.

[Van Rijn]

We are not dealing with evidence (my bold in your quote above) in any empirical sense, but the application of a philosophical methodology in a logical and consistent sense. Big difference.

And that is exactly the reason for this argument: You are not applying the methodology logically and consistently.

You came to a conclusion (that all theories have a time limit and will be falsified) without demonstrating any possible logical process by which you could reach that conclusion.

You have denied an obvious consequence of your conclusion (if all theories will be falsified, then all theories are false) without demonstrating any logical reason for your denial.

Further, when references are presented that refute your position, you simply deny them.

Your position is untenable, Sparky. Are you having trouble with the logic, or is it simply that you don't want to admit you are wrong?

[TheBlackCat]

Further, when references are presented that refute your position, you simply deny them.

The worst part is that the references that refute his position but he is ignoring are his references. He is the one who posted them in the first place, claiming they were evidence for his position.

[AstroSmurf]

I actually *hope* our current theories will be falsified, preferably in my lifetime. This is because the implication is that there is still something more to be learned. If we've learned all that there is about the structure of the universe, that would be dreadfully boring, don't you think?

[Sparky56]

I actually *hope* our current theories will be falsified, preferably in my lifetime. This is because the implication is that there is still something more to be learned. If we've learned all that there is about the structure of the universe, that would be dreadfully boring, don't you think?

This hits at the whole beauty of Falsificationism. While it may seem negative to some, I prefer to see it as encouraging progress, and discouraging stagnation. Like you say, there will always be something more to be learned.

Popper said that 'braver theories' are preferable. They are, by definition, more at risk, but science has always been about pushing boundaries.

As Popper said, perhaps the falsification of a theory should be celebrated, as ultimately it marks progress. He saw theories as a series of steps on a ladder which advance our knowledge.

Edit: Grammar

[Sparky56]

You came to a conclusion (that all theories have a time limit and will be falsified) without demonstrating any possible logical process by which you could reach that conclusion.

This is not my conclusion. It is the implication of the method, and the logical consequence of its application.

Popper said: "Falsification is the anticipated fate of all genuinely scientific theories!"

Whether this happens now or after we die is irrelevant. If we ever assume that a theory has passed all possible tests, then we will be failing in our duty to push the boundaries. We should never rest on our laurels.

[Sparky56]

The worst part is that the references that refute his position but he is ignoring are his references. He is the one who posted them in the first place, claiming they were evidence for his position.

Admittedly, it is always dangerous to link to outside materials, as there is no guarantee as to its accuracy, not even at wikipedia, for example. Some of the web sites I linked to were vague and/or complex and tangental.

I should have stuck to my voluminous collection of Popper material.

[Sparky56]

You have denied an obvious consequence of your conclusion (if all theories will be falsified, then all theories are false) without demonstrating any logical reason for your denial.

This, I'm afraid, is the logical consequence of the method. All theories, according to Popper, are but steps on a ladder. Additionally, this attitiude of mind prevents stagnation.

Perhaps it is better to see the method as the series of logical steps, below.

"No scientific theory can be conclusively verified, only conclusively falsified."

"Falsification is the anticipated fate of all scientific theories."

"That a theory is false does not mean it cannot have verisimilitude."

"Our knowledge can only be finite, while our ignorance must necessarily be infinite."

I cannot state strongly enough that I do not necessarily agree with the method in its entirety and its implications, I am simply working to it.

[Sparky56]

I say there is an invisible elf in my backyard. How do you prove that I am wrong?

I think this strapline is very telling.

I could not 'prove' you wrong, as you could make a series of claims, such as "The invisible elf only shows himself to me, on very rare occasions, and is immune to all conventional tests, but I know he is there, and I have passed all relevant sanity tests, and wy wife is a psychiatrist, and she believes me, and I am a respected scientist, etc., etc."

However, I could apply Falsifiability.

As there are no conceivable tests that could falsify the claim, given your defensive and stubborn stance, then I would have to conclude the following.

The claims are not testable / falsifiable, and are therefore not scientific.

This does not mean that your claims are without merit, however, as Popper was always keen to stress, it just means that the claims are not scientific. The elf might be an enriching experience for you, just as, it might be argued, astrology is for others.