What Is "falsifiable"?

[Moronium]

 If a statement would require exact and total knowledge to show it to be false, then it is not falsifiable.  

 

According to whom?

 

 

"All swans are white" can be proven false and is hence a falsifiable statement, since evidence of black swans proves it to be false, and such evidence can be provided. Were the statement true, however, it would be difficult to prove true.

A statement, hypothesis, or theory has falsifiability or refutability if there is the possibility of showing it to be false. It is falsifiable if it is possible to conceive an empirical observation which could refute it.^[1]

For example, the universal generalization that All swans are white is falsifiable since it is logically possible to falsify it by observing a single swan that is not white.

 

https://en.wikipedia.org/wiki/Falsifiability

 

 I can make an unfalsifiable statement that can be shown to be false. 

 

 

This sounds like a contradiction in terms, to me.

Edited April 29, 2018 by Moronium

[JMJones0424]

Yes.  All swans are white is falsifiable because in order to show the claim to be false, you need to observe one swan that is not white.  "There are no white swans" is an unfalsifiable statement, because in order to show it to be false, you must observe all swans and show that none of them are white.

 

If your question is according to whom, then you are missing the point.  The point is that the questioner doesn't matter.  The knowledge of the questioner doesn't matter.  Nothing about the questioner matters.  The problem is in how you are structuring the claim.  If the claim requires knowledge short of omniscience to show it to be false, then it is falsifiable.  "All swans are white" is a falsifiable claim.  If the claim requires omniscience to show it to be false, such as "There are no white swans", then the claim is unfalsifiable.

[Moronium]

  "All swans are white" is a falsifiable claim.  If the claim requires omniscience to show it to be false, such as "There are no white swans", then the claim is unfalsifiable.

 

So, you say, but I still can't make any sense of what you're saying.  Although they are not identical, the two statements you make here, they are saying the same thing as it pertains to white swans.

 

If the claim is there are NO white swans. then finding even one white swan would falisfy it.  It is merely the negation of the falsibile claims that "all swans are white."

 

 

Again, I think the problem is that you are conflating falsifiability with veracity.

 

 

 

 

I do think think there's some confusion here, I just don't think it's me that's confused, I guess.  I have addressed this specific difference, at some length, several times already.  No one ever responds to a word I say or points out anything that they think is wrong with my analysis.  They just come back and repeat what THEY have alealy said several times.

 

From wiki, again;

 

All swans are white" can be proven false and is hence a falsifiable  statement, since evidence of black swans proves it to be false, and such evidence can be provided. Were the statement true, however,it would be difficult to prove true.

 

Edited April 29, 2018 by Moronium

[Moronium]

I had said:

 

Although they are not identical, the two statements you make here, they are saying the same thing as it pertains to white swans. If the claim is there are NO white swans. then finding even one white swan would falisfy it.  It is merely the negation of the falsibile claims that "all swans are white."

 

 

 

The wiki article, which summarizes Popper's analysis, makes this point very specifically when it says:

 

Popper noticed that although a singular existential statement such as 'there is a white swan' cannot be used to affirm a universal statement, it can be used to show that one is false: the singular existential observation of a black swan serves to show that the universal statement 'all swans are white' is false—in logic this is called modus tollens. 'There is a black swan' implies 'there is a non-white swan', which, in turn, implies 'there is something that is a swan and that is not white', hence 'all swans are white' is false, because that is the same as 'there is nothing that is a swan and that is not white'.

 

 

It has been suggested that I "read carefully."  I'm making the same suggestion, in return.

 

Maybe it's the negations that are causing the confusion.

 

Falisfying in the clam that "all swans are " white by finding a black swan would AlSO falsify the claim that "there are no black swans."  And, conversely, finding a white swan would directly falsify the claim that "there are no white swans."

Edited April 29, 2018 by Moronium

[Moronium]

For some reason, my posts are not showing up correctly, and any editing I to do to make them right doesn't get posted at all  So some of these posts I've make are incoherent.

Edited April 29, 2018 by Moronium

[JMJones0424]

So, you say, but I still can't make any sense of what you're saying.  Although they are not identical, the two statements you make here, they are saying the same thing as it pertains to white swans.

No, the two claims "All swans are white" and "There are no white swans" are decidedly not identical, and the implications of these two claims are quite different.  I have repeatedly tried to describe why these two claims are different (the difference has nothing to do with our knowledge of the color of swans), and the very reason they are different is the reason why the concept of falsifiability exists.  I don't know how to make it more clear to you.  The only thing I can recommend is that you reread the wikipedia pages you've cited, read some of Popper's works, reread this thread, or pay someone to tutor you.  I can not overcome the problem in understanding that we are having.  FFS, the quotes you are giving support the understanding of falsifiability that I am trying to convey.

 

"All swans are white" is a statement of fact that, if it were correct, would describe our current knowledge of swans.  In the event that a swan was found that was not white, then this claim could be shown to be false.

 

"There are no white swans" is also a statement about our current knowledge, but it is not a statement of fact, as it is a claim that describes all swans, even those that we have not observed.  Even in our imperfect knowledge, we may think this claim is accurate, but in order to show it to be false, we must observe all swans.

 

Falsifiability is precisely the difference between "All swans are white" and "There are no swans that are white".  If you insist on glossing over the difference of these two claims, then it isn't surprising that you are having a hard time understanding what falsfiability is.

 

Take it out to a further level of abstraction.  "All x are y" and "all x are not y" are falsifiable statements, but "There are no x that are y" is an unfalsifiable statement.  This holds whether you observe x or not x or green x or black x or supermassive x or any other qualification of x.  The problem is that you are getting hung up on the particulars rather than the structure of the claim.

 

EDIT: I edited this post for clarity before the following posts replying to it were made.

Edited April 29, 2018 by JMJones0424

[Moronium]

.  "There are no white swans" is an unfalsifiable statement, because in order to show it to be false, you must observe all swans and show that none of them are white.

 

 

 

 

This is incorrect.  That's what you'd have to do to PROVE the statement, not falsify it.  You'd only have to observe one swan (not all swans) which was white to falsify the claim.

 

I'm sure there's someone here who understands this.  Maybe they will chime in and be able to explain it in some other way than I have.

Edited April 29, 2018 by Moronium

[hazelm]

No, the two claims "All swans are white" and "There are no swans that are not white" are decidedly not identical, and the implications of these two claims are quite different.  I have repeatedly tried to describe why these two claims are different, and the very reason they are different is the reason why the concept of falsifiability exists.  I don't know how to make it more clear to you.  The only thing I can recommend is that you reread the wikipedia pages you've cited, read some of Popoff's works, reread this thread, or pay someone to tutor you.  I can not overcome the problem in understanding that we are having.  FFS, the quotes you are giving support the understanding of falsifiability that I am trying to convey.

JM, I remembered something this morning and we have all experienced this.  In a recent book I was reading, a scientist talked about - I think he called it "brain block".  You simply cannot think something through to the answer.  His recommendation is what we've all experienced at one time or another.   Leave it.  Set it aside.  Then, about 2:00 AM, you suddenly awaken and see the light. Get up, walk around, think it through and - I love quoting my young friend - Bob's your uncle.

 

Oddly, just recently, this has been happening to me when I'm in the kitchen washing dishes or preparing something boring so my mind wanders.  Suddenly, there it is.

 

One more.  A teacher used to tell us not to review for a test the night before the test.  Review earlier and then set it aside.  Find something fun to do.  Or, clean house.  Anything but think of that upcoming test. 

 

So, dare I say forget it for a few hours or a day?  It might work. 

[Moronium]

I had said:

 

Maybe it's the negations that are causing the confusion.

 

 

I affirm the claim that "All Swans are white,"

 

I deny the claim that "Some swans are not white" and/or that "There exists a swan that is not white."

 

Same claims. Same criterion for falsifiabilty, to wit:

 

Observe a swan that is not white.

Edited April 29, 2018 by Moronium

[JMJones0424]

No, it's not incorrect, Moronium.  I was editing my post while you replied, and I apologize.

 

However, the very point of falsification is avoiding the very fact that we can not prove anything in science.  A good way of describing the situation is that because we have limited knowledge, we can not ever prove anything to be correct, therefore the best we can do is to prove that things are incorrect.  It is also possible to show that all swans are white, but it is not possible without omniscience to show that no non-white swans exist.

Edited April 29, 2018 by JMJones0424

[Moronium]

I guess we will always disagree then.  Two negatives make a positive.

 

A claim saying "It is true that no swans are non-white"  has  precisely the same substantive content as does the statement "All swans are white."  The form of the claim does not change the substance.

 

If you don't agree with that, then so be it.

Edited April 29, 2018 by Moronium

[JMJones0424]

Two negatives make a positive is irrelevant.

 

"It is true that no swans are non-white" and "All swans are white" are both falsifiable claims, and are not equivalent to "There are no white swans", which is unfalsifiable.

 

Here's why.  Not x is not y is falsifiable for the same reason that  x is y is falsifiable.  We can observe that for every x, y.

 

There is no x that is Y is not falsifiable.  The reason why is that in order to test this claim, we must observe every x, and we are not omniscient.

Edited April 29, 2018 by JMJones0424

[Moronium]

Once again you say: (for about the 5th time).

 

 "There are no white swans" is unfalsifiable

 

.

 

Finding a white swan, anywhere, any time, any place is at least theoretically possible, and that would immediately falsify the claim being made. To FALSIFY this claim would not require that you know the color of every swan in the universe.  That's only what would be required to PROVE, not FALSIFY, the claim.

 

I'm just repeating myself now, too.  We're just going around in circles.  You've said nothing which addresses my position, other than to deny it, and hence have done nothing to persuade me that I'm wrong.

 

Although the claim quoted is OPPOSED to the claim that "all swans are white," they can both be falsified in the same way, i.e., find a single instance where the claim is untrue.  In one case you would need to find a white swan, in the other a non-white swan.  That is not a difference in "falsifiability."  It's just a difference in the content of the specific falsifying observation needed.

 

Only a single exception is required because both claims are universal and absolute in form, not qualified.  They are both different than than saying, for example, *some* swans are white or *some* swans are not white.  That may be where your confusion is, I don't know. But it would require knowledge of ALL swans in order to falsify a qualified claim, so maybe that's what you're thinking of.

 

As I've noted before (as wiki also has) proof and falisifiability are kinda inversely proportional.  It is virtually impossible to PROVE a universal claim, but a universal claim can, in theory, at least, be rather easy to falsify.  On the other hand, qualified claims can, in theory at least,  be easily proven but almost impossible to disprove (falsify).  If I can find one white swan, then I will have proven my claim that "some swans are white," for example (which would, incidentally, falsify the claim that "no swans are white").  But finding 10,000,000 green swans without ever finding a single white one would NOT falsify the claim that "some swans are white."  It would easily disprove the claim that "all swans are white," however.

 

This is what I was implicitly pointing out, way back in post 22, when I said:

 

 

Suppose one of my homeys claims that "all grass is blue," and I claim that "all grass is green."

 

If I can find a single piece of green grass, then I have disproved (falsified) his claim.

 

But I have by no means proved my claim.

 

Edited April 29, 2018 by Moronium

[Moronium]

 "There are no white swans" is unfalsifiable

 

If you changed this claim to say that the proposition "Some swans are polka-dotted" is unfalsifiable, then I would, as practical matter, agree.  That's why I'm thinking that the confusion may come from miscontruing the quantifiers (All, No, Some) employed.

 

On the other hand the claim that "NO swans are polka-dotted," as plausible as it sounds (and therefore perhaps likely to be accepted without further reflection), is technically speaking, falsifiable, not unfalsifiable.

 

As I said before, Popper's distinctions have received criticism from various quarters, but he's the one who introduced the concept of falsifiability as a criterion for separating science from non-science. And, by his definition, the claim "NO swans are polka-dotted," is falsifiable.  Why?  Because, in theory at least, you could discover a polka-dotted swan, and that would disprove the claim.

Edited April 29, 2018 by Moronium

[Moronium]

Karl Popper is generally regarded as one of the greatest philosophers of science of the 20th century....

 

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....The logic of his theory is utterly simple: if a single ferrous metal is unaffected by a magnetic field it cannot be the case that all ferrous metals are affected by magnetic fields....

 

 

https://plato.stanford.edu/entries/popper/

 

That's not the whole story, of course:

 

Methodologically, however, the situation is much more complex: no observation is free from the possibility of error—consequently we may question whether our experimental result was what it appeared to be.  Thus, while advocating falsifiability as the criterion of demarcation for science, Popper explicitly allows for the fact that in practice a single conflicting or counter-instance is never sufficient methodologically to falsify a theory, and that scientific theories are often retained even though much of the available evidence conflicts with them, or is anomalous with respect to them.

 

 

 

... if a single ferrous metal is unaffected by a magnetic field it cannot be the case that all

ferrous metals are affected by magnetic fields....  By that same token, "if a single ferrous metal is unaffected by a magnetic field it cannot be the case that NO ferrous metals are unaffected by magnetic fields." 

 

Changing the form of the claim from positive to negative changes neither the substance, or the means of  falsifying, a claim, eh, JM?

Edited April 29, 2018 by Moronium

[Doctordick]

I am of the opinion that you are all dropping out a very important aspect of logical analysis by presuming that the only purpose of logical analysis is to provide actions. I put forth that the true purpose of logical analysis is to discover the consequences of collections of specific presumptions. If you limit those presumptions to only those you believe to be true, you have constrained your examination to an extreme minority of possibilities: i.e., there could exist a vast quantity of alternate possibilities which mankind will never even begin to examine. Is anyone even interested in thinking about that issue?

[Moronium]

I am of the opinion that you are all dropping out a very important aspect of logical analysis by presuming that the only purpose of logical analysis is to provide actions. I put forth that the true purpose of logical analysis is to discover the consequences of collections of specific presumptions. If you limit those presumptions to only those you believe to be true, you have constrained your examination to an extreme minority of possibilities: i.e., there could exist a vast quantity of alternate possibilities which mankind will never even begin to examine. Is anyone even interested in thinking about that issue?

 

Yeah, Doc, that's the kinda issue that I find interesting.  I completely agree with your claim, but I don't see why you say that we are all "dropping out" of it.

 

The thread topic here is the "meaning" of "falsifiable" (as a matter of definition, not logical implication) as I read it and as I have been discussing it, that's all.

 

If you limit those presumptions to only those you believe to be true...

 

 

To my chagrin, that is a tendency which I have discovered to be rather prevalent in this forum so far.

Edited April 29, 2018 by Moronium