To prove that "no swan is black", you would need to examine all currently-living swans, all swans that have lived in the past, and (if you want to be properly thorough) all swans that will ever live in the future. Impossible. You can't prove a negative.

That's just what your gut tells you. :razz: — Coben

To prove that "no swan is black", you would need to examine all currently-living swans, all swans that have lived in the past, and (if you want to be properly thorough) all swans that will ever live in the future. Impossible. You can't prove a negative. — Pattern-chaser

Well, you can prove analytical negatives, right off the bat. No bachelors are married.

But again 1) all swans are white
is the positive formulation of that and has exacly the same problems.

Each time you focus on the negative, it seems to me you think it has a special problem.

It seems to me, possibly, there is a conflation between evidence of absence and proving a negative.

And in the realm of proofs, again, all statements

you would need to examine all currently-living swans, all swans that have lived in the past, and (if you want to — Pattern-chaser

Well, the verb 'is' eliminates the time jumping. But this is all true for the positive. Not sure how we got back here to this again.

[It] is perfectly possible to prove a negative
— Filipe

No, it isn't. — Pattern-chaser

I used this quote from Stephen Jay Gould recently in a different thread. Thanks for the chance to use it again:

“In science, ‘fact’ can only mean ‘confirmed to such a degree that it would be perverse to withhold provisional assent.’”

Given that definition, it is perfectly possible to show that a negative statement is a fact, i.e. is proven.

Each time you focus on the negative, it seems to me you think it has a special problem. — Coben

No...

But again 1) all swans are white is the positive formulation of that and has exactly the same problems. — Coben

...yes, it does. But you still can't prove a negative. Just like you can't prove some positives. :up:

No bachelors are married. — Coben

The proof here refers to the definition of the term "bachelor", which is "unmarried male". Thus it is disproved by definition, which is a somewhat trivial case, don't you think? :razz:

...yes, it does. But you still can't prove a negative. Just like you can't prove some positives. — Pattern-chaser

Well, let's find a positive we can't state as a negative to see if it makes sense to make it seem like some positive we can prove. I mean, I thought we agreed that all of science was revisionable and thus not proven. So what are these positives that we can prove?

The proof here refers to the definition of the term "bachelor", which is "unmarried male". Thus it is disproved by definition, which is a somewhat trivial case, don't you think? :razz: — Pattern-chaser

I called it analytical (as opposed to synthetic). Actually I think there are non-trivial examples of this, though it has to be more complex definitions.

Well, the verb 'is' eliminates the time jumping. — Coben

OK, so to prove that "no swan is black", you would need to examine all currently-living swans. No matter where they're hiding. Impossible, in practice (which is all that matters). It can't be done, in the real world we live in.

OK, so to prove that "no swan is black", you would need to examine all currently-living swans. No matter where they're hiding. Impossible, in practice (which is all that matters). It can't be done, in the real world we live in. — Pattern-chaser

I already acknowledged that. And it's exactly the same as all swans are white, which you acknowledged. So what's with the negative. If you want to argue 'some swans are white is provable' then you are going against what you agreed with earlier that all of science is inductive and thus open to revision. Perhaps it will turn out they are not swans or it is not white, but soem other color our eyes register as white or _______________some unknown thing that means that they really weren't white that we can't think of now.

So what are these positives that we can prove? — Coben

Well, if we take "prove" to be more or less absolute in its meaning, then I suspect there's nothing we can prove. And if we dilute its meaning to avoid this problem, what we are left with is 'proof' that is sort of probable or likely, rather than, er, proof.

Impossible, in practice (which is all that — Pattern-chaser

Which is a negative claim and thus unprovable. yet, you seemed to intend to prove it.

Well, if we take "prove" to be more or less absolute in its meaning, then I suspect there's nothing we can prove. And if we dilute its meaning to avoid this problem, what we are left with is 'proof' that is sort of probable or likely, rather than, er, proof. — Pattern-chaser

Well, if we are dealing with probablities, then we can start doing this with negatives.

and then we need to deal with which qualities of swans are part of the definition of swans. Can I say there are no swans without fur instead of feathers? Are there intermediate examples that are analytic? Is black one of them?

So what's with the negative? — Coben

you still can't prove a negative. Just like you can't prove some positives. :up: — Pattern-chaser

===============================================

Which is a negative claim and thus unprovable. yet, you seemed to intend to prove it. — Coben

No, I stated it without proof, as proof is impossible. Where there can be no proof, we can only trade (what we think are) possibilities, n'est ce pas? :wink:

Can I say there are no swans without fur instead of feathers? — Coben

We could begin by telling the absolute truth, as we understand it, and see where we can go from there?

We have never seen or heard of a swan with fur, so we believe there are no furry swans.

There, a belief and its justification, simply presented. No claims to proof. :up:

No, I stated it without proof, as proof is impossible. Where there can be no proof, we can only trade (what we think are) possibilities, n'est ce pas? :wink: — Pattern-chaser

So, then, like with positive assertions, we can argue in terms of probability. Or we are simply reduced in all things to trading assertions. So, your argument in favor of your assertion that one cannot prove a negative was an attempt to say it was unlikely, for reasons X and Y. That's our position in terms of postive assertions also.

We could begin by telling the absolute truth, as we understand it, and see where we can go from there?

We have never seen or heard of a swan with fur, so we believe there are no furry swans.

There, a belief and its justification, simply presented. No claims to proof. :up: — Pattern-chaser

Sure, agreed, but that wasn't my point. My point was that the difference between analytic and synthetic statements is not so cut and dried.

And the general point is that both positive and negative statements cannot be proved. So to keep saying negative statements cannot be proved implies something specific about negative statements. And note, generally the idea is used as a critique of using absence of counterevidence as supporting evidence that something exists. Certainly many negative assertions seem as easy to show they are probable as positive statements. Your father is not dead. You father is alive. Negative statements are not a specific case. And yes, I haven't proven that negative assertion.

Neither of us have proven our negative assertions about negative assertions.

And the general point is that both positive and negative statements cannot be proved. So to keep saying negative statements cannot be proved implies something specific about negative statements. — Coben

There is something specific about negatives: it is impractical (as in 'impossible in practice') to prove them. That some positives also show this property does not affect the truth of this, does it?

The specific thing about negatives is that they are framed in such a way that proof becomes impossible because of the way they're framed. This only applies to some positives, I think?

There is something specific about negatives: it is impractical (as in 'impossible in practice') to prove them. That some positives also show this property does not affect the truth of this, does it? — Pattern-chaser

I've asked you for postives that don't show this property. You acknowledged that all of science does not show this property. And scientific conclusions are generally framed in the positive. Give me the bones, man.

The specific thing about negatives is that they are framed in such a way that proof becomes impossible because of the way they're framed. This only applies to some positives, I think? — Pattern-chaser

Well, let's find out together.

The specific thing about negatives is that they are framed in such a way that proof becomes impossible because of the way they're framed. — Pattern-chaser

I don’t see how that’s the case. “The cat is not on the mat” - why is that statement impossible to prove? Surely it’s just a matter of observing that the mat doesn’t have the cat on it.

Interesting.

You acknowledged that all of science does not show this property. — Coben

I remember acknowledging that proof is often difficult to achieve in practice. But the problem, I think, is not positives or negatives but "proof".

If we (briefly) consider "objective", we get absolute and dilute meanings, and people say it meaning it in its absolute version ("corresponding to that which actually is"), but - eventually, after interminable discussion - admit that only the dilute version ("impartial; unbiased") actually applies. [Correct use of the absolute meaning is much more difficult to justify.]

"Proof" is easier, as its definition holds it close to its absolute meaning: an unambiguous demonstration of the correctness of something. And this is very difficult to achieve, it seems to me. :chin:

Well, let's find out together. — Coben

:up: Works for me. :smile:

“The cat is not on the mat” - why is that statement impossible to prove? — AJJ

I don't think it is ... because it is clarified and focussed by the context you provide. "The mat" is a small thing, small enough to be examined in sufficient detail that we can positively confirm the absence of a cat on the mat. A (much) bigger mat would make proof much more difficult. An even less constrained description might render it impossible.

I remember acknowledging that proof is often difficult to achieve in practice. But the problem, I think, is not positives or negatives but "proof". — Pattern-chaser

Dats what I saying, man.

"Proof" is easier, as its definition holds it close to its absolute meaning: an unambiguous demonstration of the correctness of something. And this is very difficult to achieve, it seems to me. :chin: — Pattern-chaser

Yes.

“The cat is not on the mat” - why is that statement impossible to prove?
— AJJ

I don't think it is ... because it is clarified and focussed by the context you provide. "The mat" is a small thing, small enough to be examined in sufficient detail that we can positively confirm the absence of a cat on the mat. A (much) bigger mat would make our lives more difficult, making proof much more difficult. A wholly unconstrained description might render it impossible. — Pattern-chaser

I agree. But then there doesn’t appear to be anything about negatives qua negatives that makes them impossible to prove; but you seem to have acknowledged as much already, so there you go.

But then there doesn’t appear to be anything about negatives qua negatives that makes them impossible to prove — AJJ

Well, this would seem to apply (only) to negatives with unconstrained contexts. Specifically, it applies to statements for which empirical verification (or falsification) is impossible in practice (even if it might be possible in principle).

But then there doesn’t appear to be anything about negatives qua negatives that makes them impossible to prove
— AJJ

Well, this would seem to apply to negatives with unconstrained contexts. Specifically, it applies to statements for which empirical verification (or falsification) is impossible in practice (even if it might be verifiable in principle). — Pattern-chaser

I agree, but that’s also the case with positive statements: “The cat is on the mat” is impossible to prove in practice in the same way the negative statement is, if the mat is large enough. You appeared to be saying this problem is specific to negatives.

You appeared to be saying this problem is specific to negatives. — AJJ

I started off thinking it was, but it isn't. Nevertheless the old saying - you can't prove a negative - still stands. It's just that other things also can't be proven, for similar reasons. :up:

OH, thank God, I can go to sleep now.

I started off thinking it was, but it isn't. Nevertheless the old saying - you can't prove a negative - still stands. It's just that other things also can't be proven, for similar reasons. :up: — Pattern-chaser

Well, then, self-contradiction still remains for disproving.

Well, then, self-contradiction still remains for disproving. — PoeticUniverse

:chin: Er, what?