If there's no conceivable experiment that could contradict your claim then it's meaningless. Just because there might be other ways for a claim to be vacuous doesn't mean the necessary condition above doesn't hold.
1. 'Conceivable experiment' is a changing definition, since the realm of what humans can conceive is always expanding with the growth of technology and knowledge. If we had been around 2000+ years ago, would you have considered Democritus's atomic theory to be meaningless, given the lack of any conceivable path to test it at the time?
Either you have to take quite an expansive view of what is 'conceivable', or admit that 'meaningless' here refers more to practical difficulties that may be temporary, rather than anything inherent in a particular claim.
2. If we turn your statement back on itself, statements about meaning are also statements about the world (after all, what is 'meaning' if it doesn't involve what humans think and believe?). Is your statement that 'only falsifiable claims are meaningful' itself falsifiable? If so, what sort of experiment would you set up to test it?
Strictly speaking Democritus's atomic theory is still untestable today because it doesn't include the actual scale of the atoms. For all we know the apparently continuous quantum fields are themselves made of "atoms" (in his sense, not the modern meaning of the word atom). If he had said "things will get clearly atom-y around a nanometer" then it would have been at least conceivable that someone could eventually look that closely.
>you have to take quite an expansive view of what is 'conceivable'
That's right, I was laying down a very liberal criteria (and saying that it was a necessary but insufficient condition).
>If so, what sort of experiment would you set up to test it?
That's kind of like asking what sort of experiment could disprove the law of the excluded middle: not an unreasonable question, but the answer is going to sound pretty silly. To test my claim, you could iterate though every claim about the universe, checking to see if it simultaneously could not contradict with any observation, and yet predicted what you would observe. Good luck actually doing it; but it does technically meet my criterion.
> but the answer is going to sound pretty silly.
Yes, I was trying to illustrate that the line between 'science' and 'metaphysics' is necessarily a blurry one, and the choice of (and justification for) where to draw it itself lies in the realm of metaphysics.
The broader the universe of claims you admit as scientific, the more 'testability' and 'falsifiability' lie closer to the realm of theory. However, even theories (and paradigms) that can't be directly placed on the experimenter's bench today can point towards fruitful lines of investigation.
On the flip side, we can't but to make metaphysical (and therefore non-scientific) claims and hold them as true, despite our best efforts ... the strong version of 'scientism' (that only scientific claims can have meaning) is a self-defeating one.
As a mathematician, I've always looked on this issue with some bemusement. Physicists are particularly egregious in their abuse of mathematical notation, yet get very fussy about what constitutes "proof." If we consider a result measured to "five nines" of uncertainty -- scratch that -- if we consider a million results measured to "five nines" of uncertainty, than we're almost certain to have "proved" a falsehood. And that's assuming that everybody is using complete models with no missing variables (protip: they're not). And then they turn around and heap scorn on "soft sciences" which deign to apply scientific methodology to systems too small, and far too complicated for such simplistic modeling, where experimentalists jump through extraordinary hoops to avoid ethical disasters.
The need for falsifiability is a strongly-held opinion. And don't get me wrong, it's a great rule of thumb. From a mathematical basis, I can take a stab at your question. If you have a million data points, you can find a million-degree polynomial to fit it. If you're allowed to adjust the polynomial every time we make a new observation, it's unfalsifiable. However, that approach is rightly seen as problematic because the predictive power (that is, meaningfulness) is zero. But of course, this is only an existence proof (aka, an anecdote), that some unfalsifiable theories are meaningless. It doesn't prove that all unfalsifiable theories are meaningless.
I agree, however, that it was not meaningless - that should be reserved for ideas that are unfalsifiable in principle, such as p-zombies
With regard to point 2, if 'only falsifiable claims are meaningful' is not falsifiable, then it might indicate that it is not a scientific theory -- but no surprise there, as it is just a personal opinion, as is whether or not you agree with Popper.
As it happens, I think it is falsifiable, in general - mathematical identities are not falsifiable, if you include the relevant axioms, and they are not meaningless. It's pretty clear, however, that whatshisface's comment was intended in the context of science.
Math papers say, "If you follow these induction rules from these definitions and axioms you will arrive at these results." That's falsifiable, in fact it is found to be false every now and then.
It occurred to me this morning that one idea, that is looked on with interest by scientifically- and technically-minded people, is that we're living in a simulation. While there are ways that the truth of this might become apparent, I am not sure it is falsifiable, and that might be good reason to ignore it, but it is not simply a meaningless idea.
When you think of a simulation, you might imagine a programmer, some server racks, and maybe a broader purpose. However you also have to include the possibility that the simulation popped into existence out of nothing, that the simulation is mathematically inevitable, that God created the simulation, that the simulation was created by beings that live in simulation... In so many words, the idea that you live in a simulation leaves as many options open as the idea that you live in the universe. You don't get any claims about how the simulation got there, how it behaves, or even what it is
Maybe it is a meaningless idea.
I would think that, on the contrary, the fact that you can raise these objections indicates that the simulation hypothesis is not without meaning, as does Scott Aaronson's argument that it is unfalsifiable[1] (note: he is not saying that that it is meaningless), and as does Bostrom's argument that if it is possible, we are likely in a simulation[2].
If you want an example, consider an ordinary empirical observation. Someone claims the ball is red; you look and you see green. Classic contradiction, right? Except if lighting conditions are wrong, or there is a pane of colored glass between you, or.. The point is that there are additional claims that, if they were true, would remove the "contradicts" relation between the two original claims. But ordinary logical relationships shouldn't work like that.
If you don't mind me getting on my soap box, it kind of seems like the recipe for coming up with a renowned counterargument to a technical tool goes like:
- Find a technical device that you don't understand.
- Misuse it because you don't understand it.
- Notice that it isn't working.
- Conclude that logic doesn't work, math doesn't work, science doesn't work, the bug is in the compiler, take your pick.
Every experimentalist realizes that their real result is "I didn't make a mistake -> the answer is X," not "the answer is X." That's the correct way to encode an experiment in logic, leaving aside the high sophistication of how "I didn't make a mistake" gets treated in practice.
Not confirming his existence as an immaterial man, unless you're willing to take his word for the fact that he was recently immaterial.
If I appear in your country and tell you that I'm from the country of "Balanava," I'm not a confirmation of the claim that the country of "Balanava" exists. At best I'm a support.
The point is he exists and his existence cannot be falsified (while immaterial) but his existence can still be confirmed.
Let's call him person X. So, the statement "person X exists" is empirically meaningful even though it cannot be falsified.