Yes. And reaching (more or less) that conclusion, we can say that A is the ambiguous here. Right? — javi2541997

No, because if "sometimes tells the truth" doesn't mean "only sometimes tells the truth" then "sometimes tells the truth" is consistent with "always tells the truth", and so there may in fact be two people who always tell the truth.

In such a scenario it would be that both A and B always tell the truth and C always lies.

If A sometimes tells the truth it means he can also lie as well as B. — javi2541997

That is unclear. Prima facie these might mean two different things:

1. I sometimes tell the truth
2. I only sometimes tell the truth

Strictly speaking (1) might be true even if I always tell the truth. It is ambiguous as to whether or not (1) entails (2).

If it doesn't then the question is even more problematic as the person who sometimes tells the truth might always tell the truth, and so we have two people who always tell the truth.

I think you are confusing matters by being imprecise with your descriptions.

There are three types of person:

1. The person who always tells the truth
2. The person who always lies
3. The person who sometimes tells the truth

Person A can tell the truth but cannot be the person who always tells the truth.
Person A can lie but cannot be the person who always lies.

Person A is the person who sometimes tells the truth. If Person C is the person who always tells the truth then Person A is lying. If Person B is the person who always tells the truth then Person A is telling the truth.

I've made a few edits to my first comment since I first posted it. If you haven't already, refresh the page and check it out. It should answer everything very clearly.

He's using unclear wording, but when he says "ambiguous person" he means "the person who sometimes tells the truth". He doesn't mean "the person whose role is ambiguous". — flannel jesus

Gotcha, thanks.

But what happens to A then — javi2541997

A is the person who sometimes tells the truth.

B cannot be the truth-teller. — javi2541997

That depends on whether or not "I sometimes tell the truth" entails "I sometimes lie". If it does then B is not the truth-teller. If it doesn't then the answer is undecidable.

Nonetheless, it seems the riddle turned out with A being the ambiguous person — javi2541997

No, B is the ambiguous person given the ambiguity of the phrase "I sometimes tell the truth".

Among persons A, B and C one person always lies, one person always tells the truth and one person sometimes speaks the truth, hence being ambiguous.

We get the following statements:

Person A claims person B always tells the truth.
Person B claims person B (himself) sometimes tells the truth.
Person C claims person B always lies. — javi2541997

If "sometimes tells the truth" entails "sometimes lies" then:

If Person A is the person who always tells the truth then Person B is the person who always tells the truth. This is a contradiction. Therefore, Person A is not the person who always tells the truth.

If Person A is the person who always lies then Person C is the person who always tells the truth. If Person C is the person who always tells the truth then Person B is the person who always lies. This is a contradiction. Therefore, Person A is not the person who always lies.

Therefore, Person A is the person who sometimes tells the truth, Person B is the person who always lies, and Person C is the person who always tells the truth.

And you think it is possible to claim that one of the contractors is more reliable without at the same time saying that he is more likely to fulfill his obligations? — Leontiskos

In this context what is the difference between these two propositions?

1. He is more likely to fulfil his obligations
2. He is more likely to complete the contract

If they're the same then I have no objections, except to point out that the introduction of the term “obligation” is unnecessary, and evidently susceptible to misunderstanding.

If they're different then I need (1) explained, and to know why (2) is not a sufficient account.

She bound herself to you. She placed herself under an obligation. — Banno

Which still needs to be explained.

I've offered my own understanding of obligations; they are commands treated as if they were truth-apt propositions, but as commands are not truth-apt propositions obligations are a fiction, and barely even sensible.

If this account is incorrect then please provide a correct account, else how am I to even understand what you are trying to argue? All I can point out is that your conclusion does not follow from Searle's list of necessary and sufficient conditions, which you yourself directed me to. You appear to misinterpret his conditions (7) and (8). They only describe what S intends to happen. S intends to be placed under an obligation (and for H to know this), but this does not prima facie entail that S is placed under an obligation (whatever an obligation is), much like intending to be President does not entail being President.

She undertook to marry you. — Banno

She intended to marry me. That’s all there is to it.

Either she reneged on that obligation or you allowed her to leave it. — Banno

You still haven’t explained what an obligation is.

As a specific example: my girlfriend promises to marry me, but several weeks later changes her mind.

Is my girlfriend obligated to marry me?

What even is an obligation? She just either does or she doesn’t.

Well, what is a promise, if not the undertaking of an obligation? — Banno

Searle’s conditions (1) - (6) (and maybe sometimes even (7) and (8)).

These do not entail the undertaking of an obligation.

People want a contractor who will build them a house; they don't want a contractor who will not build them a house.

You are really overthinking this.

Well, if you don't like the word 'obligation', then instead of trying to convince the judge that you have no obligation to fulfill your contract you should convince him that you need not fulfill the contract and that you need not be punished. After all, why must you fulfill the contract? Why must you be punished? Why must you do what the law tells you to do? Why must you do what you said you were going to do when you signed the contract? — Leontiskos

The law simply says "if someone does not fulfil the terms of their contract then they are to be jailed". The judge then rules that I did not fulfil the terms of my contract and so orders the bailiffs to take me to jail.

Again, the existence of some supposed obligation is utterly irrelevant.

Well, suppose your judge is a good philosopher, and he admits that laws cannot be premised on non-existent realities. And really, wouldn't any logical person affirm the same? So why not explain to the judge that you agreed to the contract when you signed it, but you disagree with it now? Do you think you would have a plausible argument to convince an impartial judge? Do you think you have good arguments to convince him that there is no metaphysical basis for obligations, and therefore obligations cannot exist, and therefore you do not owe me $25,000? If your arguments are sound, then why not apply them in real life? — Leontiskos

The terms of the contract simply say "Michael is to build the house or pay a fine". The law simply says "if someone does not fulfil the terms of their contract then they are to be jailed".

Neither the contract nor the law depend on the existence of obligations, and so arguing that obligations don't exist is an irrelevant argument.

But why? Why not reason with the authority and explain to him, like you did to me, that you intended to fulfill the contract when you signed it and now you've changed your mind? If you are not obliged to pay the contract, then surely you are not subject to further punishment...? — Leontiskos

I can say whatever I want. I doubt it would convince a judge. The contract states that if I do not build the house then I am to pay a fine. The law states that if I do not pay the fine then I am to be jailed. So I build the house, pay a fine, or go to jail. Unless I have very good lawyers, I have to choose between one of these outcomes.

That's all there is to the matter. I don't see what role obligations have – or even what obligations are, as both you and Banno refuse to make sense of them.

Earlier you told me that you honestly believe that you can just change your mind and decide not to fulfill a promise. Why can't you just change your mind and decide not to fulfill a contract? Why not just tell the authority that you've changed your mind and decided not to fulfill the contract? — Leontiskos

I can do all of that. And then I will presumably face some further punishment.

Did you tell him you changed your mind? — Leontiskos

I don't understand the relevance of the question. If you're asking what I would do in real life then I would either pay the fine or hire lawyers to find a way to save me from paying the fine.

Why is the authority fining you? — Leontiskos

For not doing what I was contracted to do.

As in, "If I don't build the house on time then some authority will fine me."

This is true if in the terms of the contract. But this does not prima facie entail "I ought build the house" (or "I ought pay the fine").

Well, you are the one who told me that you owed me the money. What did you mean when you affirmed that proposition? — Leontiskos

I was thinking of it in terms of the conditional "If I don't do X then Y will happen", and that this proposition does not entail "I ought X".

So if you change your mind and renege, do you still owe me the money, or not? — Leontiskos

Right, by "owe" you mean "obligated to give you the money"? Again, you haven't told me what it means to be obligated to do something. I just either do it or I don't.

Why couldn't you just say, "I changed my mind," like before? (↪Michael) When I say that you owe me $25,000, why couldn't you change your mind? — Leontiskos

Well I can certainly change my mind and not give you the money, and then face whatever punishment follows.

I don't really understand your question.

then you seem to be claiming that making a promise is not undertaking an obligation — Banno

Yes. I've been very clear on that. This is true even using Searle's definition of a promise. Your claim that if S promises to do A then S has undertaken an obligation to do A is as of yet unsupported.

Take a contract. You tell me that you will build me a house in a year, and if you don't complete it in that time you owe me $25,000. The year completes and the house is not completed. Do you owe me $25,000? — Leontiskos

Yes.

If you do not agree that someone who undertakes an obligation is not thereby obligated, then I have no more to offer you. — Banno

That's not what I'm saying. I am saying that Searle's conditions – even with conditions (7) and (8) – do not entail that when one promises to do something one is agreeing to undertake an obligation.

You are just reasserting the very thing that needs to be justified.

I am curious whether you think contracts exist. If no one is obliged to fulfill a promise, then surely no one is obliged to fulfill a contract? — Leontiskos

Yet again you still haven't told me what it means to be obliged to do something.

You will say, I think, "There is a penalty but no obligation." But then what is the one who breaks contract being penalized for? Is there something he failed to do? — Leontiskos

He didn't do what he was contracted to do and so as per the terms of the contract (or the law in general) he is penalized.

That's all there is to it. I don't understand what this additional thing – the "obligation" – is, or what part it plays.

Without (8), the promise does not count as undertaking an obligation. — Banno

Even with (8) it doesn't count as undertaking an obligation.

Here are two propositions:

1. S intends to produce in H the knowledge that the utterance of T is to count as placing S under an obligation to do A.
2. The utterance of T is to count as placing S under an obligation to do A.

Searle uses (1), and (1) does not prima facie entail (2).

Perhaps an obligation is a binding of an individual to the performance of an act. — Banno

This is yet another thing that needs to be explained. What does it mean to be "bound" to the performance of an act?

I just either do it or I don't. What are these other things you're trying to introduce?

So for Michael promises don't exist — Leontiskos

That depends on what you mean. Here are two propositions:

1. Promises exist
2. People promise to do things

If (1) and (2) mean the same thing then I agree with (1). If they mean different things then I need an explanation of this difference.

Michael is presumably saying that obligations don't exist — Leontiskos

That depends on what you mean. Here are two propositions:

1. Obligations exist
2. People command others to do things

If (1) and (2) mean the same thing then I agree with (1). If they mean different things then I need an explanation of this difference.

The backstop here is the way you will also claim that terms like 'ought' and 'should' make no sense to you if they are interpreted in their colloquially normative sense. See our conversation where you do precisely this: link. — Leontiskos

The colloquially normative sense is just to treat a command as if it were a truth-apt proposition. It's fictionalism. If you think there's more to it than that then I'd need an explanation and a justification for them.

Sorry - can you give an account of what making a promise is, that does not involve placing oneself under an obligation? — Banno

Searle's conditions 1-6 that you linked me to. I would copy them here but I cannot copy and paste from that document and I'd rather not manually type it all out.

Is it your contention that one ought not keep one's promises? — Banno

My contention is that a) it hasn't been explained what obligations are and b) it hasn't been explained how/why promises entail obligations. Even Searle's account doesn't explain this.

It appears we disagree as to the nature of "obligation". — Banno

I don't even know what an obligation is, if something more than a command. I have asked several times for an explanation.

Can you offer an alternative meaning for "promise" — Banno

Searle’s conditions 1-6 seem sufficient. But again, even 7 and 8 don’t entail the existence of an obligation.

As a first response, if you are given a command, by someone with the authority to command you, then "do this" does imply "you ought do this" — Banno

The problem with this claim is that I cannot make sense of the difference between “do this” and “you ought do this”. At best it just claims that “do this” entails “do this”.

You seem to have missed the point. The utterance of T counts as placing S under an obligation to do A. — Banno

I haven’t missed it. I’m asking you to justify this claim. It doesn’t follow from Searle’s list of necessary and sufficient conditions. His conditions only talk about intending to be placed under an obligation, but intentions do not prima facie entail the intended.

Your mention of Anscombe was interesting. Do you care to fill it out? — Banno

Here are two sentences:

1. You ought do this
2. Do this

The first appears to be a truth-apt proposition, whereas the second isn’t. But beyond this appearance I cannot make sense of a meaningful difference between them. The use of the term “ought” seems to do nothing more than make a command seem like a truth-apt proposition. It’s make-believe a la fictionalism.

Considering that analytic philosophy, as it is today rather than relating to Frege and the Vienna Circle, is a phenomenon particular of the English-speaking world, I wouldn't say so. I at least have not seen any book written in German about what 'wissen' mean or in Spanish about 'conocer'. — Lionino

Well, Plato certainly asked that question in ancient Greek. It's where "justified true belief" comes from.

I'm sure people of other languages make the same arguments about the words in their language – some of which may be exactly translatable into English with no change in meaning, and some of which may not.

Is this like "analysis of knowledge" in analytic philosophy where whole books are written about the meaning of a specific word because the dictionary definition is not specific enough for the taste of the philosophers in question? — Lionino

Something like that.

For example, I think that this is a sufficient account:

a) I promise to do something. If I do it then I did as I promised. If I don't do it then I didn't do as I promised.

Whereas others want to bring in talk of obligations and being held to a promise and of promises existing. It isn't clear what any of these things mean, or what they add to (a). To borrow from Anscombe, they seem like terms with "mere mesmeric force" and no real substance.

I'll make this exceptionally simple for you @Banno, as it seems I must.

Prima facie these are two different propositions:

1. S intends that the utterance of T will place him under an obligation to do A
2. The utterance of T will place S under an obligation to do A

In Searle's list of necessary and sufficient conditions, he uses (1) – and (1) does not prima facie entail (2).

As a comparison, these are two different propositions:

3. S intends to do A
4. S will do A

In Searle's list of necessary and sufficient conditions, he uses (3) – and (3) does not entail (4).

To defend your position you must either show that (1) entails (2) (and justify Searle's claim that (1) is a necessary condition) or find some other way to justify (2) – as well as actually explain what obligations are.

Michael, how odd. — Banno

The only oddity is why you continually misrepresent what I am saying.

I am saying that you haven't shown that anyone places themselves under an obligation when they promise something.

It certainly doesn't follow from Searle's account, even if his conditions (7) and (8) are correct. Intentions do not prima facie entail the intended.

And that is the sort of thing you tell your professional clients? — Leontiskos

No.

What relevance is this question?

Sufficient to avoid the conclusion that your promise was insincere. — Leontiskos

My promise was sincere because I intended to fulfil it when I made it. I was being honest at the time. I just happened to change my mind after making it.