It is absurd to assert or believe both of them at the same time. — Luke

It's absurd to believe both at the same time as then one would be holding contradictory beliefs.

But why is it absurd to assert both at the same time? We've already established that "it is raining" and "I believe that it is not raining" are not contradictory statements.

"It is raining outside" - when and if if spoken sincerely - is spoken by a language user who believes that it is raining outside. — creativesoul

Right. So now you have to ask yourself why this is the case. Why is it that "It is raining outside" - when and if if spoken sincerely - is spoken by a language user who believes that it is raining outside?

What is the necessary link which makes it impossible for someone to sincerely say "It's raining outside" (a statement about the state of affairs of the world), when they believe it is not (a state of their internal mind)

Again, what does sincerity have to do with it? What it means and whether or not it's true has nothing to do with what the speaker believes. — Michael

Seeing how we're talking about the absurdity of particular belief statements, and the two are contradictory, and it is impossible to believe both at the same time, it matters.

You might have missed my edit. Again, from SEP:

The common explanation of Moore’s absurdity is that the speaker has managed to contradict himself without uttering a contradiction. So the sentence is odd because it is a counterexample to the generalization that anyone who contradicts himself utters a contradiction.

Seeing how we're talking about the absurdity of particular belief statements, and the two are contradictory, and it is impossible to believe both at the same time, it matters. — creativesoul

Again, I'm not saying "I believe that it is raining and I believe that it is not raining". I'm saying "It is raining and I believe that it is not raining".

There is only one belief; the belief that it is not raining. So where is this contradiction?

The common explanation of Moore’s absurdity is that the speaker has managed to contradict himself without uttering a contradiction. — Luke

So could you explain the manner in which he is contradicting himself? If the sentence isn't the contradiction then what is?

Asserting something to be true, while simultaneously asserting your belief that it's not true. Why would you assert it to be true if you don't believe it? And why would you not believe it if you are asserting it to be true?

Why would you assert it to be true if you don't believe it? — Luke

My name is Andrew. The Moon is made of cheese. Liquorice is delicious.

There are many reasons that one might assert something that they don't believe to be true. But what does the motivation of the speaker have to do with it?

Why is it that "It is raining outside" - when and if if spoken sincerely - is spoken by a language user who believes that it is raining outside?

What is the necessary link which makes it impossible for someone to sincerely say "It's raining outside" (a statement about the state of affairs of the world), when they believe it is not (a state of their internal mind) — Isaac

Why do we need a link that makes it impossible to sincerely say "It's raining outside" if we do not believe that that's true? Belief presupposes truth. One cannot believe both simultaneously; that it is raining outside, and that it is not raining outside.

There's no link needed here that I can tell...

That's just how meaningful belief and statements thereof work(s).

Again, I'm not saying "I believe that it is raining and I believe that it is not raining". I'm saying "It is raining and I believe that it is not raining".

There is only one belief; the belief that it is not raining. So where is this contradiction? — Michael

If you're sincerely saying that it is raining, then you believe it is raining. If you believe that it is raining, then you cannot believe that it is not.

My name is Andrew. The Moon is made of cheese. Liquorice is delicious.

There are many reasons that one might assert something that they don't believe to be true. But what does the motivation of the speaker have to do with it? — Michael

As I said, the absurdity is in the dual assertion. You need to deal with both parts of the assertion, not just one. Otherwise, you're not really talking about Moore's paradox.

If you're sincerely saying that it is raining, then you believe it is raining. If you believe that it is raining, then you cannot believe that it is not. — creativesoul

Maybe I'm not saying it sincerely. As I've said, people can lie. I'm lying when I utter "it is raining and I believe that it is not raining" but a lie is not the same thing as a contradiction or an aburdity.

As I said, the absurdity is in the dual assertion. You need to deal with both parts of the assertion, not just one. — Luke

But what is absurd about asserting "it is raining" and "I believe that it is not raining"? You keep saying that it sounds absurd without explaining what about it is absurd. We've already established that the two sentences mean different things, have different truth-conditions, and can both be true. So where exactly does the problem arise?

...a lie is not the same thing as a contradiction or an aburdity. — Michael

That one is.

I did explain it above. You didn't respond to it (to both aspects of it). To repeat:

Why would you assert it to be true if you don't believe it? And why would you not believe it if you are asserting it to be true?

One cannot believe both simultaneously; that it is raining outside, and that it is not raining outside. — creativesoul

Right. But we're not necessarily talking about simultaneously believing both, not yet.

All with have are two propositions with two different truth-makers. If the truth of "It is raining" is determined by whether it's raining, not by whether I believe it's raining, then I can say it is truthfully raining, but I don't believe it is.

The problem here is caused by the contradiction between a philosophical commitment to correspondence theory, and the actual psychological reality that the truth of a statement is always a judgment and always based on the belief of the person doing the judging.

I did explain it above. You didn't respond to it (to both aspects of it). To repeat:

Why would you assert it to be true if you don't believe it? And why would you not believe it if you are asserting it to be true? — Luke

I did respond. There are lots of reasons that someone might lie. But what does their reason for lying have to do with the supposed absurdity of the assertion?

That one is. — creativesoul

How so? It's just a lie. We've already established that the two parts of the sentence are not contradictions.

There are lots of reasons that someone might lie. But what does their reason for lying have to do with the supposed absurdity of the assertion? — Michael

I don't see what difference lying makes. Even if I were to lie in asserting that it's raining, what sense does it make to also assert that I don't believe that it's raining?

I don't see what difference lying makes. Even if I were to lie in asserting that it's raining, what sense does it make to also assert that I don't believe that it's raining? — Luke

You're asking about the speaker's motivation, but what's the relevance of that? We're discussing the sentence, not the speaker. Or are you saying that the absurdity is that you can't make sense of why the speaker is uttering the sentence?

The absurdity is in someone asserting ‘P and I don’t believe that P’ (or ‘P and I believe that not-P’).

The absurdity is in someone asserting ‘P is true but I don’t believe P’. — Luke

Allegedly, but you still haven't explained why it's absurd. Why is it absurd to truthfully assert that you don't believe P and at the same time to (insincerely) assert P? We've already established the the statement contains no logical contradiction, so the absurdity, if there is one, doesn't seem to be with the sentence itself. Is it, as I suggested, that you just can't understand why anyone would say such a thing?

The absurdity is in someone asserting ‘P is true but I don’t believe P’. — Luke

Only on the assumption that "P is true" means "I believe that P is true, or I wish to give the impression I believe P is true". That's the origin of the apparent paradox. Correspondence theory would have that "P is true" simply means P, not "I believe that P". If we're to accept this, then there should be no absurdity. There is absurdity, so we must reject this. Wittgenstein, Moore and Ramsey all reject it in different ways, but the point of the paradox is to get us to reject it somehow.

Let me see if I follow your thinking here. Let’s assume it’s not really raining, but I lie about it. I assert ‘It’s raining but I believe it’s not raining’. This is a perfectly logical thing to say?

Let me see if I follow your thinking here. Let’s assume it’s not really raining, but I lie about it. I assert ‘It’s raining but I believe it’s not raining’. This is a perfectly logical thing to say? — Luke

It's logical in the sense that the sentence contains no contradiction. And given the facts, it's false. But were it raining (unbeknownst to you) then it would be true.

Correspondence theory would have that "P is true" simply means P, not "I believe that P". — Isaac

Yes, I edited that comment to "The absurdity is in someone asserting ‘P is true but I don’t believe P’", but too late it seems. [Edit: Oops looks like the edit didn't take. I had edited it to be 'P but I don't believe P' (or 'P but I believe not-P). Oh well.]

If we're to accept this, then there should be no absurdity. There is absurdity, so we must reject this. Wittgenstein, Moore and Ramsey all reject it in different ways, but the point of the paradox is to get us to reject it somehow. — Isaac

Right, well, at least you accept that there is a paradox, unlike several others here.

It's logical in the sense that the sentence contains no contradiction. And given the facts, it's false. — Michael

Well, you've only lied about it raining, not about your belief, so is it true or false?

Well, you've only lied about it raining, not about your belief, so is it true or false? — Luke

It's false, as I said above. And were it raining it would be true. Either way, there's no logical contradiction. Just an ordinary truth or falsehood.

Right, well, at least you accept that there is a paradox, unlike several others here. — Luke

Sort of. I actually hold to Ramsey's solution that truth dissolves to the success of beliefs, so I think the paradox has been solved, but I agree there was one.

Edit - I don't want to give the impression here that Ramsey's work was a response in some way to Moore's puzzle. Only that it is a solution to it. I'm unclear on the historical facts, but I'm pretty sure that's not how it actually played out. There's no direct mention of it in Ramsey's writing, to my knowledge.

Then it is also false regarding your belief?

Then it is also false regarding your belief? — Luke

It's true regarding your belief. It's false regarding the weather. As a conjunction it's false.

Whereas if it were raining then it would be true regarding your belief, true regarding the weather, and so as a conjunction it would be true.