I am strong believer in the verification principle as a criterion for meaningful propositions. A.J. Ayer distinguished between two different types of verification. There is strong verification and weak verification. Strong verification refers to statements which are directly verifiable, that is, a statement can be shown to be correct by way of empirical observation. For example, 'There are human beings on Earth.' Weak verification refers to statements which are not directly verifiable, for example 'Yesterday was a Monday'. The statement could be said to be weakly verified if empirical observation can render it highly probable.

What exactly is the nature of historical knowledge. Is it possible to know the past? Based on these two types of verification, I suppose we can say that historical knowledge is a matter of weak verification.

Weak verification appears to be a kind of pragmatic form of the principle. What are some other examples of weak verification that you find useful for making sense of the world in which we live?

But the distinction does not help to justify the verification principle as a criterion of meaningfulness. The trouble with the verification principle is that it cannot be formulated in a way that both, and at the same time. will include sentences which are clearly meaningful, and, exclude meaningless propositions.

Here is the classic paper on this issue. It is worth studying.

Hempel, "Problems and Changes in the Empiricist Criterion of Meaning"

But the distinction does not help to justify the verification principle as a criterion of meaningfulness. The trouble with the verification principle is that it cannot be formulated in a way that both, and at the same time. will include sentences which are clearly meaningful, and, exclude meaningless propositions.

Here is the classic paper on this issue. It is worth studying.

Hempel, "Problems and Changes in the Empiricist Criterion of Meaning"

The other problem of course is the verification principle can not be verified.
Sort of a liars paradox problem.

Logical positivism takes all the fun out of speculative or classical philosophy.

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.

Yes, but that was not my point. My point, and the point of the paper, is that the verification principle cannot be correctly formulated so as to do what it is supposed to do. Namely, eliminate the meaningless, and include the meaningful. If it does one, it cannot do the other. (A little like the principle of indeterminacy in QM about position and velocity).

Would you like to give me a quick rundown of why the verification principle cannot eliminate meaningless statements and include meaningful ones?

I did not mean cannot. I meant, has not, so far. And that is why it has been pretty much abandoned. Read Hempel for the history of failed attempts to do it. That is what Ayer's distinction between weak and strong verification tries to do. Eliminate what needs elimination, and admit what should be admitted. Wittgenstein's PI was, in part, a reaction to this futility.

I only believe that if a statement is unverifiable then it is meaningless as a proposition. I've made a distinction between two different senses of meaning in philosophic language. One sense refers to mind-independent facts of the world that can be verified by empirical observation and the other sense refers to subjective sentiments that are not matters of knowledge or truth, but matters of sensory value. What's wrong with this interpretation of the verification principle?

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 suppose that depends on what you mean by the word God. Can we prove the existence of a supernatural spirit that doesn't want to reveal itself to everyone? I would say no. "There are ETs somewhere" is verifiable in principle, but that wasn't my point. My point was that if someone were to say that "ETs exist" then they would be making a false proposition because it has not been verified. It would be better to say that "ETs may exist" or "I believe that ETs exist".

But what is meant by God is the traditional meaning, and the question is whether there is a God is meaningless or not on the verification principle. Is the ET thing strongly or weakly verifiable? Apart from that, is it meaningless? And if on some formulation of the verification principle it turned out to be meaningless, would that not lead you to abandon that formulation? Or would you simply say, it was meaningless. You have to test philosophical theories by their consequences. That is pragmatism.

You cannot mean that it would be false if not yet verified. You think that since it has not been verified that cancer is caused by a virus, that it is false that cancer is caused by a virus? You subscribe to the principle that what is not yet known to be true, is false?

If one is referring to the traditional meaning of God, I would say that the statement "God exists" is meaningless as a proposition. What's your take on it?

The ET thing is strongly verifiable in principle. I would say that it's meaningless if it is stated as a proposition but not as a question or a simple belief. I think that our disagreement here is mainly due to what we mean when we say that something is meaningless. By meaningless I only mean that it has not yet been proven. If someone said that "ETs exist" they would be making a declaration and yet their declaration has not been verified. What substance does a declaration hold if it has not yet been proven to be true or the declarer cannot yet prove it to be true?



Excuse me for using the wrong word. I don't mean that what is claimed to be true is false because it has not yet been proven to be true. I mean that a proposition (a statement that is declared to be true or false) that has not been proven or cannot yet be proven rests on an empty premise.

Of course I don't think it is meaningless. Why should I? And if some formulation of the verification principle implies it is meaningless, then I would just reject that formulation of the VP since I am far more certain that the sentence is meaningful than I could possibly be that the formulation that implies it is meaningless is correct.

I don't know what an empty premise is. So, I wouldn't know. And neither would I know how it rests on it if I did know what an empty premise is, which I do not.

What do you mean when you say that the sentence "God exists" is meaningful? Do you believe that it can be proven to be true or false?

People like me, understand what it means. No, I don't believe it can be proven true or false.

I understand what it means in definitive terms, but when I say that it's meaningless I mean that it can't be proven to be true or false and yet it is stated to be true.