In that case I guess that people who say that cancer is caused by a virus are saying something meaningless. They would be surprised to hear it.
Philosophy is in essence I would say rational speculation.
Logical positivism reduces "meaningful"philosophy to that which can be verified.
Science reduces natural philosophy to that which can be "falsified"
The question of "God exists" would if true; be a matter of "ultimate concern" and "infinite meaning" but it can neither be verified or falsified (although particular religious assertions and conceptions of god can be falsified I would assert).
Even unverifiable assertions may be matters of "meaning" and areas of rational speculation although perhaps not "meaningful propositions" in the rigid logical and analytic realm of positivism.
If you agree that the statement "cancer is caused by a virus" cannot be proven and you believe that the statement "God exists" cannot be proven then what's the epistemic difference between the two statements?
---------- Post added 02-28-2010 at 10:38 PM ----------
All of this ignores my distinction between meaningful propositions and meaningful questions. The question "does God exist" is meaningful in a sentimental or axiological sense.
Also, although this is a bit off topic, if a God did exist it wouldn't seem to matter much seeing that the world operates as if a God doesn't exist.
I didn't say they cannot be proven. They certainly have not been proven. And you said that what cannot be proven is meaningless. Do you think that the sentence cancer is cause by a virus if it cannot be proven, is meaningless? Is the question is cancer caused by a virus meaningful only in a sentimental sense? Anyway, I thought you said that God exists is meaningless, so how can you speculate about what would be true if the meaningless sentence was true or false?
How do you know that the world operates as if God did not exist? If God exists, how would you know how the world would operate if He did not?
You said that the sentence "God exists" cannot be proven. I said that what cannot be proven is meaningless as a proposition because it either cannot be proven to be true or false or has not been proven to be true or false. The question "is cancer caused by a virus" doesn't express a sentiment or subjective opinion. The question expresses curiosity about an objective fact. The difference between the two questions is that one deals in the supernatural, a state of reality that we have no knowledge of or reason to believe in, and the other deals in things that we know exists (viruses and cancer).
Nature doesn't operate as if it were controlled by volition or will. It operates according to lawlike regularities.
Then you had better distinguish between two kinds of meaninglessness. One that deals with objective fact, and another that deals with the supernatural. Since it is possible that neither is provable.
What makes you think that if God existed, Nature would not operate according to law-like regularities? Most theists think that God operates through the laws of nature.
I see your point. The problem with the verification principle is that there is no way to thoroughly justify what it deems to be meaningless or meaningful. But there is no difference between telling someone to prove something and telling someone to verify something . . . Wouldn't you agree?
If God operates through the laws of nature then my claim still stands. The laws of nature do not operate as if they are controlled by volition or will.
No. I could accumulate evidence for some proposition without having proved it.
No. This may be how it is when the laws of nature are controlled by volition.
The problem with the verification principle is that there is no way to thoroughly justify what it deems to be meaningless or meaningful.
What do you mean by that?
So asking someone to prove something is different from asking someone to verify something? What's the difference between proof and verification?
This may also be how it is when the laws of nature are controlled by scooby doo, too, if you ignore what it's like for an object to be controlled by volition or will. The reason why we can make far more accurate predictions about inanimate objects than we can about animals is because inanimate objects have no volition or will.
You pointed out the difficulty of deeming a sentence meaningless because it hasn't been verified or cannot be verified. You made this point with the proposition that "cancer is caused by a virus" and the proposition that "God exists". Did I miss something else?
1. I thought that you verify a proposition when you give evidence for it, and that you prove it when the evidence you give for it is enough to show it is true.
2. Yes, it might be controlled by Scooby Doo.
3. No, you did not miss something. I did not know what your meant.
1. How do we determine that enough evidence has been given to prove that a proposition is true?
2. Is there anyway to know that it's not controlled by Scooby?
1. I think that would depend on the context.
2. I don't know. Maybe.
How do you tell whether a statement is verifiable or not? Is that God exists verifiable? (After we are dead, maybe). Some people think it is verifiable right now. Is it? Apparently you think that there are ETs somewhere is not verifiable. But a lot of scientists think it is (in principle). In fact, they are looking for evidence. Isn't that what Ayer's distinction between strong and weak verification is about? Strong verification omitted what was clearly meaningful. So he had to weaken the criterion. But what does the now weakened criterion permit? How about, that God exists? Which positivists held was meaningless. And which strong verification would not allow.
I'll take a look at that paper, but I would say that the verification principle can be justified by a pragmatic meta-consideration of knowledge.
The weak version of verificationism cannot handle to the so called 'tacking problem' (basically nothing can be excluded from being meaningful, as others already pointed). Of course one can add further a criterion of simplicity but anyway that one has to explain not only how can we strongly justify the principle of simplicity (at the moment only a heuristic methodology in Science, Bayesianism is no solution either) but also why a supernatural creator (who can interact with the physical world at will) cannot become part of an extended science of tomorrow in spite of the possible existence of extraordinary evidence* (I'm afraid the demarcation between Science and metaphysics is very rough, some metaphysical concepts at one epoch may very well become 'normal science' at a later time, sometimes after very long periods of time).
*a God interested in human affairs is at least indirectly confirmable via his actions in Nature, providing extraordinary, objective, evidence of course. Now it is indeed hard to make a clear difference between genuine supernatural interventions and (still) unknown natural causes when strong violations of the known laws of physics are observed (although I am not so sure that this demarcation is impossible). Yet one can much more easily conceive situations when methodological supernaturalism could become the first choice methodology in Science. For example Dembsky "asks us to suppose that astronomers discover a pulsar billions of light years from earth, the pulses of which signal English messages in Morse code. Further, these messages invite us to ask it questions, including problems that can be shown mathematically to require for their solution far more computational resources than are, according to our best estimates, available in the universe. We then receive verifiable answers to these questions in ten minutes". This scenario does not corroborate clearly the God hypothesis (if confirmed) but it is enough extraordinary to put methodological supernaturalism on a par with methodological naturalism; more such extraordinary scenarios would at least make methodological supernaturalism the first choice methodology in Science (further one can argue that many such extraordinary violations could be seen as corroborating the existence of some sort of Creator - existing from eternity - in such a way that we can even talk of a provisional truth; of course, as anyone minimally accustomed with Philosophy knows well, defining knowledge does not require epistemic certainty).
My discussion with Kennethamy and my own contemplation on this issue has prompted me to drop the verification principle in my philosophy of language. Thanks to everyone who contributed to the thread and my clarification of the issue.