Hinge propositions seeming to be what R. G. Collingwood calls absolute presuppositions. More to them than just a name. RGC argues that usually they are too far removed from current thinking to be a present part of "the game." E.g., Magnus Carlsen does not think about whether the chess board is 8x8 or 9x9: the rules are long given and understood, and not in the course of the game thought about.

And the distinction between absolute and relative presuppositions, and presumably thereby absolute and relative hinge propositions. The relative are part of the structure of the immediate enterprise, and the absolute instead what the enterprise is grounded upon. I may relatively presuppose my bicycle is in the entry or on the street. If not one then the other. But that I have a bicycle I absolutely presuppose. If my bicycle is neither on the street nor in the entry, I may well then question where it is. Stolen? Borrowed by a friend? Left by me somewhere else and I forgot where? But the question if I have one never arises. And if it did then the enterprise of wondering where it is would be rendered nonsensical.

RGC identifies presuppositions as answers to questions - not always or necessarily explicitly asked, or spoken aloud.

The trick is to come to understand that hinge propositions, or presuppositions, relative and absolute, far from being rare, are instead as thick around us in our thinking as air that we breathe. As noted

the question of the existence of God from a nonreligious person makes no sense in a religious game. — Eskander

And this is exactly right. Not right or wrong, but nonsensical. And this being fully realized, one is almost entirely innoculated against dogma of all and any kind.

Another application would be in religious language game, the question of the existence of God from a nonreligious person makes no sense in a religious game where the whole language is based around the usage of the word ,"God" . — Eskander

But the use of the word ‘God’ among the religious will
likely include doubt, since God would imply faith , which requires doubt.So I think the hinge proposition God likely includes all of this. Only in a situation where the non-religious had never heard of the concept of God could there be no shared language game.

I may relatively presuppose my bicycle is in the entry or on the street. If not one then the other. But that I have a bicycle I absolutely presuppose. If my bicycle is neither on the street nor in the entry, I may well then question where it is. Stolen? Borrowed by a friend? Left by me somewhere else and I forgot where? But the question if I have one never arises. And if it did then the enterprise of wondering where it is would be rendered nonsensical. — tim wood

This sounds more like a structure of propositional logic than a language game

Neither. Think about what you presuppose - that's not too difficult. Then, more difficult, try to figure out some things you absolutely presuppose. "Where is my bicycle?" presupposes my bicycle is somewhere. In order to ask that question - and for it to make sense - I absolutely presuppose I have and own a bicycle, that bicycles exist, & etc. That is, not a game at all, but part of the what and how of my and everyone's thinking. You get to tell me if hinge propositions seem to you to be the same thing pretty much, or not. And if not, how/why not.

All about such presuppositions here,
https://www.amazon.com/Essay-Metaphysics-R-G-Collingwood/dp/1614276153/ref=sr_1_3?crid=20GQ6PZOY5FDV&keywords=collingwood&qid=1641851816&sprefix=collingwood%2Caps%2C106&sr=8-3
A book I have referenced here many times.

Also a pdf online.

Hinge propositions seeming to be what R. G. Collingwood calls absolute presuppositions. — tim wood

When I looked up "hinge propositions" on the web, I got the same impression you did, but I'm not sure if they are the same as absolute presuppositions. Collingwood is very clear that presuppositions are not propositions, which is a conflict. Also, one of the examples of a hinge proposition in the Internet Encyclopedia of Philosophy is "I have two hands."

I accept the correction.

I accept the correction. — tim wood

I didn't intend it as a correction. I think I'm asking the same questions you are. What was Wittgenstein talking about?

The expression is used only three times.

341. That is to say, the questions that we raise and our doubts depend on the fact that some propositions are exempt from doubt, are as it were like hinges on which those turn.
342. That is to say, it belongs to the logic of our scientific investigations that certain things are in deed not doubted.
343. But it isn't that the situation is like this: We just can't investigate everything, and for that reason we are forced to rest content with assumption. If I want the door to turn, the hinges must stay put.

And later:

655. The mathematical proposition has, as it were officially, been given the stamp of incontestability. I.e.: "Dispute about other things; this is immovable - it is a hinge on which your dispute can turn."

Hinger propositions are those which must be taken as true in order to play the game. They constitute the game in that to bring them into doubt is to stop playing. Hence the usual chess examples: to doubt that the bishop must remain on one colour is not to adopt a rational critique of chess but to misunderstand the game. But stop playing the game and one can move the bishop onto the wrong colour.

Searle points out that hinge propositions set out what something counts as for the purposes of the game. Moving the bishop diagonally counts as a move in chess. It sets up what it is to move the piece in the game. It rules many possible moves - putting the piece back in the box, for example - as not being moves in the game. Of course such moves might be moves in some other game or activity - tidying up.

"God exists" does not have the structure of a constitutive proposition in the requisite sense. Some interpretations might make it so.

Introducing Collingwood seems an odd way to try to understand Wittgenstein, especially seeing as Collingwood was writing before On Certainty was published.

Thank you for the references. It appears to me that hinge propositions are if not the same as absolute presuppositions, then first cousins. But if, as you say, W. mentions them but thrice and metaphorically, RGC's laying them out in some 335 pages of very readable text would seem to be the go-to to understand them, what they are and are not, how they work and what they're for.

Hinge propositions have to be taken as factual or given in the language game you are playing and you cannot change their usage/status with certain moves in a language game. — Eskander

In another discourse, they are called axioms.

An axiom, postulate, or assumption is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Greek ἀξίωμα (axíōma) 'that which is thought worthy or fit' or 'that which commends itself as evident'.[1][2]

The term has subtle differences in definition when used in the context of different fields of study. As defined in classic philosophy, an axiom is a statement that is so evident or well-established, that it is accepted without controversy or question.[3] As used in modern logic, an axiom is a premise or starting point for reasoning.[4]

https://en.wikipedia.org/wiki/Axiom

The key difference is that a hinge proposition is not to be doubted.

An assumption might be subjected to subsequent rejection, as in a reductio argument. An axiom is taken as self-evident.

That the bishop stays on the same colour is neither subject to refutation nor self-evident, but it is a hinge for the purposes of playing chess.

A small distinction, but worth noting.

The key difference is that a hinge proposition is not to be doubted.
An assumption might be subjected to subsequent rejection, as in a reductio argument. An axiom is taken as self-evident.
That the bishop stays on the same colour is neither subject to refutation nor self-evident, but it is a hinge for the purposes of playing chess.
A small distinction, but worth noting. — Banno

"Is not to be doubted" is ambiguous. Do you mean undoubtable, as with the chess bishop? Or do you mean doubtable but not in this circumstance to be doubted?

Of course doubtable also needs qualification. There are those things manifestly doubtable but assumed for the sake of the argument. And, different, Collingwood's absolute presuppositions that are intrinsic to the enterprise and undoubtable within it, usually not explicitly or consciously made as with axioms that are unstated or never stated, but which the evolution of time and events may change or overthrow. His, then, part of the machinery of a kind of thinking.

Or do you mean that doubting is just an attitude itself absent qualification of appropriateness, and thus inappropriate for the circumstance in question. E.g., one can doubt anything, even that the chess-board bishop is constrained, but such a doubt would be absent any appropriateness playing chess.

I don't think of hinge-propositions as propositions in the normal sense of the word, which is why they're called hinges, basic. or bedrock propositions. They don't fall into the epistemological language we use, at least in terms of JTB. They're not truths, they don't need some kind of justification, at least in the way Moore was referring to them. They're more akin to the rules of chess, as has already been mentioned. Although, it seems, we can make more sense of the question, "Do bishops move diagonally?" - than we can of the question, "Do I have hands?" I don't think Wittgenstein worked this out, "having hands" seems more fundamental, more foundational, if you will, than the rules of chess (not foundational, though, as it's typically used in epistemology). Wittgenstein seems to think of them as a contingent function of the world in which we live, the backdrop of all acting, verbal and non-verbal. And, one of the things that sets them apart. as @Banno mentioned, is that doubting them, at least generally, is senseless.

It seems that just as chess needs the rules, the board, and the pieces, in order for there to be a game of chess, so too, do we need these hinge, bedrock, or foundational beliefs (I think of them as special beliefs, not as propositions) in order to have a language, especially the language of epistemology. This includes the language of doubting. They have a special place between the mind, the world, and our language, and that place is related to our actions in the world.

Do you mean undoubtable, as with the chess bishop? Or do you mean doubtable but not in this circumstance to be doubted? — tim wood

Isn't the movement of the bishop doubtable but not in this circumstance to be doubted?

Searle points out that hinge propositions set out what something counts as for the purposes of the game. Moving the bishop diagonally counts as a move in chess. It sets up what it is to move the piece in the game. It rules many possible moves - putting the piece back in the box, for example - as not being moves in the game. Of course such moves might be moves in some other game or activity - tidying up. — Banno

They're not truths, — Sam26

I think they are.

One might read "Here is a hand" as a definition of what counts as a hand, or as a real object. That's a way of understanding Moore - "This counts as a real object, therefore there are real objects". Moore would be seen as setting out the rules for discussions of reality.

While there are issues with unjustified knowledge I don't see an issue with unjustified truth. The alternative would presumably be some sort of antirealism.

While there are issues with unjustified knowledge I don't see an issue with unjustified truth. The alternative would presumably be some sort of antirealism. — Banno

Ya, I think we have a difference in the way we look at truth. If some proposition is true, then how would you know it's true without a justification? A simple claim that something is a truth, doesn't mean that it's true. I can't make any sense out of an unjustified truth, if you're saying that X is true without a justification, then the claim that it's true is more akin to an opinion. If it's an opinion, then it could just as easily be false. However, the way you're using it, is like saying, "I know it's true." A kind of knowing without justification, which seems contradictory.

If some proposition is true, then how would you know it's true without a justification? — Sam26

There's a distinction between being true and being known to be true. There are true statements that are not known to be true. Yes, that's presuming realism. That seems better option to me than working through the problems of antirealism in its various forms.

https://thephilosophyforum.com/discussion/11900/realism/p1

Give me an example of something that is true, but not known to be true? It would have to be some proposition, right?

There's a mission to Mercury by the ESA and JAXA. Part of the mission is to decide if there is water at the poles - something hinted at by previous observations.

Both the realist and the anti-realist will agree that we do not know that there is water at the poles of Mercury.

A realist will say that either there is water at the poles, or there isn't - that either the statement or its negation is true.

An anti-realist may say that the statement "There is water at Mercury's poles" is neither true nor not true, until the observation is made. — Banno

DO you really wish to work with a non-binary logic? To reject the law of excluded middle?

One might read "Here is a hand" as a definition of what counts as a hand, or as a real object. That's a way of understanding Moore - "This counts as a real object, therefore there are real objects". Moore would be seen as setting out the rules for discussions of reality.

While there are issues with unjustified knowledge I don't see an issue with unjustified truth. The alternative would presumably be some sort of antirealism. — Banno

I don’t read Wittgenstein’s discussion of hinge propositions as a justification, defense or foundation for realism. On the contrary, the ‘rules for the discussion of reality’ are themselves only the pragmatic basis for one more language game.

403. To say of man, in Moore's sense, that he knows something; that what he says is therefore unconditionally the truth, seems wrong to me. - It is the truth only inasmuch as it is an unmoving foundation of his language-games.(On Certainty)

I don’t read Wittgenstein’s discussion of hinge propositions as a justification, defense or foundation realism. — Joshs

Indeed. He explicitly rejects the arguments of both in PI.

An anti-realist may say that the statement "There is water at Mercury's poles" is neither true nor not true, until the observation is made. — Banno

The anti-realist is confused. If I make a claim, that there is water on Mercury's pole, that by definition is a proposition, and propositions can be true or false, just as any claim that's not known. If I verify that there is water on Mercury's pole, now it becomes knowledge. The use of words by the anti-realist, is, for the most part, senseless.

By the way you didn't give me an example of something that is true, but not known to be true.

Although, it seems, we can make more sense of the question, "Do bishops move diagonally?" - than we can of the question, "Do I have hands?" — Sam26

There are circumstances; phantom limbs, numbness or paralysis, alien limb syndrome, perhaps some virtual reality aps, where the possession of a hand becomes a real question. But these situations where the question becomes real and meaningful, are outside the realm in which one discusses philosophy. If I don't know whether this is my hand or not, I won't be going to a philosophy site to find out. Here we assume that we each know how many hands we got if not which orifice we speak out of.

What I've learned about multivalued logic over the last few months has left me a bit less reproachful of anti-realism. There may be ways of constructing viable multi-valued grammars around truth.

But in the end there is either ice on the poles of mercury, now, unknown to us; or there isn't, also unknown to us. While we don't know which is true, one or the other is true.

Therefore there are unknown truths.

Hence there are propositions for which the truth value is unknown.

But that is not the same as there being propositions which do not have a truth value.

So I'm going back to propositions as statements with a truth value. Not entirely without its own problems, but they seem to me to be fewer than supposing that there are propositions without truth values.

But as a final comment, if a hinge proposition is not true, then we could not make any deductions from them - hence rendering them pointless.

I had a similar conversation with a refugee who had both legs removed curtesy of an American cluster bomb, and on waking would need to check if he had legs.

And again I much prefer Austin's explanation of "real" in terms of opposites to either Moore or Wittgenstein.

What does "unknown" mean in this use? Other than we don't know if the statement is true or false. What third option is there? There are unknown truth values, but that again, just means that the proposition/statement can be true or false.
— Banno

But that is not the same as there being propositions which do not have a truth value. — Banno

Banno, these people are going in circles. Again, what does having a truth value amount to, other than being true or false? There just is no such thing as a proposition that is true, and not known to be true. What are they saying is true? That's my question, it amounts to nothing.

But as a final comment, if a hinge proposition is not true, then we could not make any deductions from them - hence rendering them pointless. — Banno

This is where I go beyond Wittgenstein, although Wittgenstein alludes to it, that these so-called hinge-propositions are just very basic beliefs, shown in our actions. With these come language itself, and then the whole of epistemology. So, they stand apart, as the background, so to speak, that gives us everything needed for our language-games. They are simply acts of a different kind than propositions, they are pre-linguistic. So, they are not pointless. In fact, they are extremely important.

Wouldn't a language with no factual basis that is nonsensical just be a private language? It seems so.

I guess it's just what we mean by nonsense.

There are circumstances; phantom limbs, numbness or paralysis, alien limb syndrome, perhaps some virtual reality aps, where the possession of a hand becomes a real question. But these situations where the question becomes real and meaningful, are outside the realm in which one discusses philosophy — unenlightened

Of course, and Wittgenstein gives examples which are exceptions to Moore's propositions, viz., that there are instances where a doubt can occur, but they are not the norm. When I talk of doubting, I'm referring to Moore's specific use of, "I know this is a hand," given in front of an audience where a doubt is meaningless.

Wouldn't a language with no factual basis that is nonsensical just be a private language? It seems so.

I guess it's just what we mean by nonsense. — Cobra

Is the game of chess based on facts, other than the rules of the game? So, language-games are based on, for the most part, the rules of grammar, and the way we use concepts within certain contexts etc. We use language to refer to facts in the world. You could say there are facts of language, some of those facts arise out of the meanings of our words. It's a fact that bachelors are unmarried, but I suppose you are referring to facts outside of language. I would say that there are pre-linguistic facts or beliefs that give rise to language.

Again with the notion of prelinguistic propositions. Seems discussing them can't be avoided.

So you must have some way to square this with "The world is all that is the case".

How?