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[Eduk]

I'd point out that the idea that evolution, or string theory, or what have you, is invalid because it's not falsifiable, is yours not mine. I'm disputing the idea that something must be falsifiable in order to be valid.

I said it seemed reasonable and that I can't think of anything which contradicts that (that is not the same as saying I think it is true). I thought it was Karl Popper's original claim by the way, not mine? As I said, according to scientific consensus, evolution is falsifiable and the most famous examples of people who don't agree with the scientific consensus are religious groups. Apologies if I'm preaching to the converted as it were.

String theory is a good example. Professional physicists don't agree String theory is a scientific theory. I have no expertise so given that I very slightly agree with some scientists in saying it isn't a scientific theory. I could easily be proven wrong however. One of the ways of being proven wrong would be to generate the techniques required to falsify it, of course then it would pass Popper's criteria. Don't get me wrong, many good theories start out with dodgy origins, so I'm not writing string theory off, I'm just doubtful.

Regarding mathematics if I gave you two apples and you already had two and then the apples were counted that would falsify whether you had 4 or not. I don't think Popper is dumb, I think his theories are interesting and quite profound, I disagree with your earlier claim that they don't really stand up to scrutiny (which seemed to me quite dismissive). I am not sure if I agree with the entirety (or parts) of Popper's work or not, I'd have to do a great deal more reading. At the least he is not trivially wrong, and if he is wrong it is subtle and nuanced.

[Dolphin42]

Togo1 to Eduk:

...I'm disputing the idea that something must be falsifiable in order to be valid.

Since this seems to be a sensitive subject for you, would you rather use Logic or Mathematics as an example of a valid, useful, non-falsifiable construct, rather than Evolution?

To avoid unnecessary confusion I think it should be pointed out that a theory must be falsifiable if it purports to make predictions about possible observations of the physical world - if it is empirical. Statements in pure logic or mathematics do not purport to do this.

[Togo1]

Ok, this is getting tangled. Can you please read carefully before replying?

I'd point out that the idea that evolution, or string theory, or what have you, is invalid because it's not falsifiable, is yours not mine. I'm disputing the idea that something must be falsifiable in order to be valid.

I said it seemed reasonable and that I can't think of anything which contradicts that (that is not the same as saying I think it is true). I thought it was Karl Popper's original claim by the way, not mine?

No. You are contradicting Karl Popper. You are saying evolution and similar theories are falsifiable, he said they were not falsifiable.

As I said, according to scientific consensus, evolution is falsifiable

I don't agree, nor did Popper. I don't agree that there is such a consensus, since all the examples you've given conflate falsifiable with useful and/or valid.

String theory is a good example. Professional physicists don't agree String theory is a scientific theory. I have no expertise so given that I very slightly agree with some scientists in saying it isn't a scientific theory. I could easily be proven wrong however. One of the ways of being proven wrong would be to generate the techniques required to falsify it, of course then it would pass Popper's criteria. Don't get me wrong, many good theories start out with dodgy origins, so I'm not writing string theory off, I'm just doubtful.

The point is that people talk about string theory because it is an useful idea, and it is valid to discuss string theory. The problem with it is not that it is falsifiable or not, but that it generates too few predictions in practice.

Regarding mathematics if I gave you two apples and you already had two and then the apples were counted that would falsify whether you had 4 or not.

Yes, but that doesn't falsify whether 2+2 equals 4 in principle. Both Mathematics and Logic are based on axiomatic reasoning, not empericism.

I don't think Popper is dumb, I think his theories are interesting and quite profound, I disagree with your earlier claim that they don't really stand up to scrutiny (which seemed to me quite dismissive).

I wasn't talking about Popper, you're misquoting me.

This is what I wrote:

]There are plenty of famous scientific sceptics, such as Pete Medewar, who claim that empericism, being the only form of knowledge subject to proof, is the only form of knowledge, and that all other knowledge reduces to science. While I can see that this is an interesting claim, it doesn't really stand up to scruntiny.

The claim that doesn't really stand up to scruntiny, in my opinion, is the one that all knowledge reduces to emperical statements. Far from being Popper's claim, it's a position that Karl Popper spent a great deal of time arguing against.

I am not sure if I agree with the entirety (or parts) of Popper's work or not, I'd have to do a great deal more reading. At the least he is not trivially wrong, and if he is wrong it is subtle and nuanced.

Well, you're the one disagreeing with him, not me.

The principles that Popper came up with was that the science, or more properly empericism, was the only means of gaining certain knowledge, because it tested propositions against reality This doesn't mean that all of science consisted of testable proposition - indeed it specifically includes both testable propositions and an explanatory framework surrounding them. That framework may not be testable, as he argued it wasn't in the overall framework of Evolution, but that doesn't stop it from being valid, useful, or the best supported explanation that exists.

I'm not sure if that's what you're aiming for, or if you're instead taking the Positivist position that only emperical statements are meaningful/valid/useful, or somewhere in between?

[Eduk]

No. You are contradicting Karl Popper. You are saying evolution and similar theories are falsifiable, he said they were not falsifiable.

I don't think I mentioned similar theories? Also Karl Popper changed his mind on evolution. Regardless it would be possible to agree with his general sentiment that all scientific theories talking about reality have to be falsifiable and disagree with his specific statement that evolution wasn't falsifiable.

I don't agree, nor did Popper. I don't agree that there is such a consensus, since all the examples you've given conflate falsifiable with useful and/or valid.

I am just saying it is the consensus of expert opinion. If you wish to get into the subject you are better off talking to a biologist than me.

The point is that people talk about string theory because it is an useful idea, and it is valid to discuss string theory. The problem with it is not that it is falsifiable or not, but that it generates too few predictions in practice.

If a prediction is testable it is falsifiable? Don't get me wrong I'm not against string theory, all I'm saying is that it hasn't been proven to be useful yet. As to whether it will be proven to be useful in the future, I have no idea. Einstein said some interesting things on his creative process, where he would attempt to think as unbound as possible, with an attempt to ignore scientific 'fact', then when he had ideas he would try to work out ways to test them, only the testable ideas are left.

The claim that doesn't really stand up to scruntiny, in my opinion, is the one that all knowledge reduces to emperical statements. Far from being Popper's claim, it's a position that Karl Popper spent a great deal of time arguing against.

But that was the claim I originally said I couldn't find when I did a google search. So I have no idea what Medewar is talking about.

Well, you're the one disagreeing with him, not me.

I didn't disagree with him in general (in fact I said he was pretty reasonable a number of times), just one specific claim on the testability of evolution which he later corrected himself.

Yes, but that doesn't falsify whether 2+2 equals 4 in principle. Both Mathematics and Logic are based on axiomatic reasoning, not empericism.

I struggle to see how you can have logic without reality. Can you think of axioms which are useful and contradict reality?

[Felix]

Eduk: can you think of axioms which are useful and contradict reality?

Mathematical axioms need not be consistent with empirical evidence, only with other axioms within a deductive system, and deductive systems contain both logical axioms (a.k.a., tautologies) and nonlogical axioms.

[Eduk]

Felix. If the axiom is non logical is it useful? I'm just saying I can't think of an example off the top of my head. I would happily consider specific examples which contradicted the idea that logic is based on empiricism. Things like the law of contradiction seem to hold up in the empirical world as well as they do in the world of logic. I'm just asking for a discussion really. I could be convinced either way.

[Felix]

If the axiom is non logical is it useful?

If by "useful" you mean having predictive value, than yes, nonlogical axioms, in combination with logical axioms, can have predictive value. Both are needed to model nonlinear systems, such as weather systems, in which there is an inherent element of randomness. Of course the predictive value would be purely statistical since we're not dealing with linear causal relationships.

[Togo1]

No. You are contradicting Karl Popper. You are saying evolution and similar theories are falsifiable, he said they were not falsifiable.

I don't think I mentioned similar theories? Also Karl Popper changed his mind on evolution. Regardless it would be possible to agree with his general sentiment that all scientific theories talking about reality have to be falsifiable and disagree with his specific statement that evolution wasn't falsifiable.

Ok, at this point I can't tell which of us is more familiar with Popper. I think you're simplifying what he wrote suffciently to be imprecise on the meaning you're summarising here, because the point is not whether we're talking about reality or not, but that science involves non-falsifiable propositions and methodologies in order to function. I'm not familiar with this supposed change of mind, although I did run across a few mentions of people disputing that he'd altered his position on evolution, and had merely clarified it.

Does anyone have a solid reference on this?

I don't agree, nor did Popper. I don't agree that there is such a consensus, since all the examples you've given conflate falsifiable with useful and/or valid.

I am just saying it is the consensus of expert opinion.

Yes, and I'm just saying it isn't. We can agree to disagree on this.

The point is that people talk about string theory because it is an useful idea, and it is valid to discuss string theory. The problem with it is not that it is falsifiable or not, but that it generates too few predictions in practice.

If a prediction is testable it is falsifiable? Don't get me wrong I'm not against string theory, all I'm saying is that it hasn't been proven to be useful yet. As to whether it will be proven to be useful in the future, I have no idea. Einstein said some interesting things on his creative process, where he would attempt to think as unbound as possible, with an attempt to ignore scientific 'fact', then when he had ideas he would try to work out ways to test them, only the testable ideas are left.

Eh, why are only the testable ideas left? What process seperates the the testable from untestable, and is that process testable? More to the point, is it falsifiable? Can any process really be said to be falsifiable?

The claim that doesn't really stand up to scruntiny, in my opinion, is the one that all knowledge reduces to emperical statements. Far from being Popper's claim, it's a position that Karl Popper spent a great deal of time arguing against.

But that was the claim I originally said I couldn't find when I did a google search. So I have no idea what Medewar is talking about.

Oh, it's the other side of the US culture wars, where rather than claiming that religious beliefs trump scientific principles, instead we have people claiming that science trumps everything else, irrespective of the source. The justification for this position usually takes the form of some kind of positivism. If you've not encountered it, we don't need to worry about it.

Yes, but that doesn't falsify whether 2+2 equals 4 in principle. Both Mathematics and Logic are based on axiomatic reasoning, not empericism.

I struggle to see how you can have logic without reality. Can you think of axioms which are useful and contradict reality?

Any form of reductionism? I'd argue that's useful.

But contradicting reality isn't necessary, merely not being connected to or relying on reality. Mathematics is full of such axioms, as is logic.

[-1-]

: can you think of axioms which are useful and contradict reality?

The square root of negative one, for instance. It is not only contradictory to reality, but it is highly unintuitive. Yet it serves a huge useful purpose in calculations to design and produce electrical circuits.

[Daviddunn]

The square root of negative one, for instance. It is not only contradictory to reality, but it is highly unintuitive. Yet it serves a huge useful purpose in calculations to design and produce electrical circuits.

I think, by saying that it is unreal/imaginary, it does not contradict reality. For example the statement "(p and ~p) is a contradiction" is not itself a contradiction but it is a tautology namely ~(p and ~p).
A complex number consists of a real part and an imaginary part. Common knowledge. Now, if you concede reality to numbers, even though they cannot be experienced by the senses like one might, for example, observe characters on a screen, then one has committed oneself to the existence of something that cannot be experienced by the senses. That is fine with me!

With this concept of reality, a class of numbers are defined as "real" and another class as "unreal/imaginary/complex". For others reading this, the "imaginary" is a misnomer! It does not mean that such number can be imagined! What this means is that: The reality that the real numbers are thought to possess is not thought to be possessed by the imaginary numbers.

So according to its very definition, i (an imaginary number, and sometimes j is used) is defined as lying outside the real field. Moreover, the real field is essential for the definition of the unreal, i.e. without the real numbers, there cannot be the imaginary numbers!  
So, it is like (p&~p) being contradictory. The axiom/definition, itself, does not contradict reality but is in fact a tautology! For ~(p&~p) is a tautology and not a contradiction!  

As you mention electrical designs; there are some other examples from electronic engineering as well. Like negative frequencies made much use in the Fourier formulas and others like this. A frequency is necessarily a positive number. But when it is interpreted in the context, negative/positive frequencies mean two rotating lines/points, one in a clockwise direction and the other in an anticlockwise direction. So if one rotating direction is considered as positive, then number of cycles per second (I.e. the frequency) is positive. And logically, the opposite direction is then considered as negative, and its frequency of rotation is given a negative sign. But in fact the frequency of both rotating devices is always a positive number!

[Eduk]

Ok, at this point I can't tell which of us is more familiar with Popper. I think you're simplifying what he wrote suffciently to be imprecise on the meaning

Yes I agree. I don't know enough about Popper's beliefs or work and I'm summarising him probably not all that well.

The quote attributed to him regarding natural selection is

Nevertheless, I have changed my mind about the testability and the logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation. My recantation may, I hope, contribute a little to the understanding of the status of natural selection.

I have found references to which book it is in and which page, but can't find the book itself to verify (with a quick search).

Really all this does is highlight just how difficult it is to draw lines of demarcation and to categorise. I can see arguments both for and against simple mathematical axioms being falsifiable or not, the example of counting apples I gave you was again something attributed to Popper and not my own idea.

-- Updated May 11th, 2017, 11:31 am to add the following --

I am just saying it is the consensus of expert opinion.


Yes, and I'm just saying it isn't. We can agree to disagree on this.

Can we at the very least clear this one up? Just to make sure we are talking about the same thing. Are you saying
Evolution isn't the consensus opinion of experts.
Natural selection isn't the consensus opinion of experts.
That evolution is falsifiable isn't the consensus.
That natural selection is falsifiable isn't the consensus.

Or do none of those statements quite suffice?
We could also be disagreeing on who the 'experts' are?
Or even I guess on what a consensus is, how many recognised experts have to support an idea (as a percentage) for it to be a consensus.

Hopefully then we can start to clear up what the consensus actually is. As surely the consensus is a matter of fact and not opinion. So we really shouldn't be disagreeing on facts.

[Togo1]

Eh, I'd say that Darwin's idea, that the origin of the species was through evolution via natural selection, is not falsifiable.

We could also be disagreeing on who the 'experts' are?

I hadn't considered that angle, but quite possibly. How many biologists do you know who are really that comfortable with falsification as a philosophical principle? And how many just treat it as an 'are you sure'?
Is it accurate to claim a consensus of philosophical opinion on any subject at all?

Or even I guess on what a consensus is, how many recognised experts have to support an idea (as a percentage) for it to be a consensus.

Eh, no, to be a consensus they'd have to support the same idea in the same way, I think. Context matters here. And I wouldn't call a controvertial topic where a bare majoirty share one view, and a minority another, to be a consensus, since that implies a level of common agreement that was absent in practice. (cf Brexit) However for a relatively uncontrovertial topic, I'd set the bar lower, since there is less barrier to common agreement.

What did you mean when you made the claim?

As surely the consensus is a matter of fact and not opinion. So we really shouldn't be disagreeing on facts.

I'm inclined to see it as a judgement call.

[Eduk]

Eh, I'd say that Darwin's idea, that the origin of the species was through evolution via natural selection, is not falsifiable.

Evolution and natural selection are two different things.

How many biologists do you know who are really that comfortable with falsification as a philosophical principle?

I wasn't talking about falsification as a philosophy. But to whether natural selection was falsifiable. These are two different things.

Eh, no, to be a consensus they'd have to support the same idea in the same way, I think. Context matters here. And I wouldn't call a controvertial topic where a bare majoirty share one view, and a minority another, to be a consensus, since that implies a level of common agreement that was absent in practice. (cf Brexit) However for a relatively uncontrovertial topic, I'd set the bar lower, since there is less barrier to common agreement

I was only saying it's the consensus that natural selection is falsifiable. I don't understand how context comes into this? And I would agree if it was controversial with a very small minority that is not the same as saying it's the consensus. 51% in favour and 49% against does not show a clear consensus in my opinion either. But I don't think there is any contention in the scientific community, there is a lot of contention outside of the scientific community but that's irrelevant as to what the consensus is within the scientific community.

What did you mean when you made the claim?

Eduk wrote:
As surely the consensus is a matter of fact and not opinion. So we really shouldn't be disagreeing on facts.


I'm inclined to see it as a judgement call.

I mean if you asked each biologist in the world if they thought natural selection was falsifiable and then asked them to answer that question with respect to a spectrum and you then collated all the responses that should show if there is a consensus on the question of whether or not natural selection is falsifiable in a factual manner.

[Dolphin42]

A falsifying observation: finding the fossilised remains of a complex life form in a pre-Cambrian rock stratum.

[Papus79]

Its incredibly difficult for anyone to be rational.

We're built for tribal life, in-group survival, procreative competition , etc.. If you're male and in your late teens or early 20's it doesn't take a whole more than a stiff breeze to remind you of that. Watching the news as well and seeing how western culture's progressing you also see that reality as it is simply isn't enough for people of all kinds of different walks of politic, philosophy, etc.. and I think it's because we really aren't built to hold truth as a primary value. Some of us might incidentally feel like truth is the only thing that'll save us from having our culture go into full neolithic atavism and yield to some sort of totalitarian frame of affairs. Others of us are somewhat inherent nerds, I'm still not quite sure how that works, but we have a gravitation toward truth and often find just how eerily lonely that can be.

The problem you also run into is careerism. It seems like once people get vested with a particular kind of institution, a particular kind of crowd, or have built up a particular theory or viewpoint for years it becomes something of a pet dogma and it can't be shaken. I can't always be sure just how much of that is the crystallization of neural structure in old age and how much of that goes to show how socially suicidal we consider the words 'Oops - I was wrong'. To a point I can't fully blame people for that second way of looking at things, ie. your life really can be turned upside down if you've sourced your value as a leader of or a scholar for people who've thought the way you always have. It's clearly not the high-road but considering human frailties it makes sense.