This inverts Wittgenstein’s entire hierarchy. You treat a hinge as a result of the examination of doubt, whereas Wittgenstein presents it as a precondition for any examination at all.
Your claim that ‘There are no hinges where there is not yet doubt’ seems directly contradicted by the learning process Wittgenstein describes. The child learns by believing the adult (160). This ‘learning by believing’ is the process of inheriting hinge propositions. There is no prior state of doubt from which these beliefs are ‘exempted’. They are exempt because they form the very ground of the language-game in which a word like ‘doubt’ has any meaning. The child learns to distrust by refining this foundational trust, not by creating it ex nihilo.
Your argument implies that the door must be able to swing before its hinges are in place. However, Wittgenstein’s central project is to describe the foundational world-picture that forms the logical backdrop to any form of questioning. To use the river metaphor: the riverbed cannot shift unless there is a riverbed there already. The ‘exemption from doubt’ (341) isn’t a result of inquiry; it is a logical precondition for it. Wittgenstein’s argument is not psychological, but logical.
That is to say, the questions that we raise and our doubtsdepend on the fact that some propositions are exempt from doubt, are as it were like hinges on which those turn.
But I don’t see that Wittgenstein is even proposing that we could have rules of application. Such a rule would have to refer to “normal circumstances”. So for the rule to be workable it would have to say what constitutes normal circumstances. However, “normal circumstances” is something we just recognize, not something stipulated by a rule
27. If, however, one wanted to give something like a rule here, then it would contain the expression “in normal circumstances”. And we recognize normal circumstances but cannot precisely describe them. At most, we can describe a range of abnormal ones.
So to me, the point he makes is that application is something different, not a rule guided judgement. We observe the circumstances, decide which rule is applicable, on a basis of something like, ‘this appears to be normal circumstances for rule X, but not rule Y’, then we apply rule x accordingly. I’d say it’s a matter of experience and intuition.
We don’t even get the appearance of regress because it’s already broken off by describing application as involving judgements which are not a rule following procedure. This is why practise becomes so important; it, as experience, provides the basis of that judgement, rather than a rule.
It doesn’t deepen the regress, it completely avoids it. He says application is not a rule based judgement. Therefore there is no regress of rules. That we cannot guarantee correctness in our judgements of application, is simply a fact of reality, outlined by the requirement of “normal circumstances”, which we cannot determine by rules. This is why a person with good intuition is better at these judgements than a person with bad intuition. But good intuition is very specifically directed, depending on one’s capabilities.
I would say that this is the right conclusion, but you came to it in a strange way. There is no infinite regress, because the demand for rules of application is in general, misguided. What guides us is practise (experience, intuition), and this is not rules.
The important point though, is that without rules we have no certainty, no guarantee of correctness. Therefore practise is carried out without certainty.
Yes, it’s based on my reading of the book. If you follow you’ll see it. To start with, notice the difference between Sam’s and my interpretation of 25-30. Sam concluded some sort of certainty (hinges perhaps) which underlie practise. I conclude that Wittgenstein demonstrated that practise is carried out without certainty.
Right. There is no prior state of doubt for the child.
To be exempt means free from the doubt that other propositions are subject to.
Again that means that hinges come later. When propositions are no longer accepted without doubt.
No. My argument is that where there is not doubt there are not hinges. Hinges are what allow us to more passed doubt. They are what is taken as established and not doubted. This does not mean that hinges are already in place in order for the child to believe. The child has no reason to not believe until it learns to distrust. This comes later.
This is completely wrong.
Right. It is what keeps inquiry from getting stuck. Certain things are established and thereby not doubted. But what those things are can change over time.
It depends on the particular case. There are things about which we are certain. The earth revolves around the sun. If this were not true then a significant part of astronomy would fall apart. I see no indication that Wittgenstein was uncertain about this. It is a hinge.
I don’t follow the logic that inheritance implies “coming later.” To inherit a world-picture is to receive the entry requirements for the game. You agreed that OC 342 refers to the structure of inquiry, yet you claim hinges are not a “condition for playing.” This is a contradiction. If the logic of investigation requires that “certain things are in deed not doubted” (342), then that exemption is the starting point. To suggest we establish hinges “late” is to say we can play the game of science before the logic of science is in place.
Hinges are not tools “to move past doubt.” They are the unmoving background against which doubting is made possible. The child learning from its parents is not in a state of neutral belief; it is in a state of immersion within a pre-existing structure of certainties. The hinges are the absorbed, taken-for-granted structure of that worldview. Doubt is a refined, specialised activity that happens much later , and only because that structure is already in place.
Moreover, “Doubt comes after belief” (160) is not merely about the child’s state of mind. It is about the logical priority of the system. To believe the adult, the child must already be standing fast on the hinges of language and the shared world-picture. If there were no hinges in place, the child’s “belief” would have no structure; it would be a blank slate without any connection to a language-game.
If hinges are only established once we “move past” doubt, then the entire structure of inquiry is built on a void until the very end of the investigation. Wittgenstein’s logic is that certain things are “in deed” not doubted (342) so that the investigation can happen now.
It was your claim that learning by believing is the process of inheriting hinge propositions.
If that was true then everything we learn is a hinge. But that is not what Wittgenstein says. It is those propositions that are exempt from doubts that are hinges. Some of those things a child is told turn out not to be things we take to be true, and so, are not hinges.
What is that inherited picture and how is that picture inherited? No one tells us that the ground will hold us up as we walk on it, or that we have legs with which to walk. At some stage we simply walk on the ground that we previously laid and sat on.
342 is about the logic of scientific investigations, not the logic of investigation.
The “game” of science requires that certain concepts stand fast. These concepts have developed over time. They are not universal. Not every culture has developed them. A people cannot do chemistry if they do not have an understanding of the concepts, principles, and methodology of chemistry.
Hinges are not the inherited background, our picture of the world is. (94) Hinges are embedded in our background but that background is much broader than hinges, which have a particular function within that background.They do not make doubt possible. They keep the door of our inquiry swinging.
The child believes the adult. Believing the adult is not a hinge. The belief has no structure. The child believes what it is told.
As children we learn facts; e.g., that every human being has a brain, and we take them on trust.
Children from primitive societies are not told that they have brains. It is something we tell our children because of advances in our understanding.
The claim that regularities in past practice have no authority to bind subsequent performances is a stronger form of rule-skepticism than Witt endorses. The rule-following passages in the PI, particularly around PI 185-242, show that rule-following isn’t interpretation all the way down. At some point we act without the interpretation. We simply follow the rule. Not because a hidden engine guides us, but because training has produced agreement in practice. That agreement isn’t a lucky coincidence we wait and see about each time. It’s what makes calculation a practice rather than a series of independent acts.
OC 39 says “This is how calculation is done. In such circumstances a calculation is treated as absolutely reliable.” OC 47 says “This is how one calculates. Calculating is this.” These aren’t invitations to see what happens next time someone calculates. They’re descriptions of a practice with a determinate character. The whole point of OC 44-47 is that the reliability of calculation doesn’t need external certification. But reliability is only reliability if there’s stability across performances. If every application is genuinely open, there’s nothing to be reliable.
You attribute to Witt the claim that the practices behind 2+2=4 have a stability “akin to a hinge.” Which remark are you drawing that from? The relationship between mathematical certainty and hinge certainty is one of the open questions in these passages. Witt draws parallels between mathematical certainty and the certainty of propositions like “here is a hand,” but he doesn’t straightforwardly identify mathematical propositions as hinges. Mathematical propositions are verified by checking, which is epistemic. OC 50 says exactly this: you say “I know” when you’ve checked the calculation. Paradigm hinges like “here is a hand” aren’t subject to that kind of verification. So the relationship between the two is something Witt is working through, not something he settles, and I don’t think it’s as neat as your phrasing suggests.
In 51-55 he is comparing the logical certainty of calculations with the certainty of empirical statements. This is a continuation of the same distinction I’ve described as the distinction between the validity of the logic, and the truth or falsity of the premises. At 55 there is a question:
55. So is the hypothesis possible, that all the things around us don’t exist? Would that not be like the hypothesis of our having miscalculated in all our calculations?
So he is asking, can we get to the same level of certainty that we get from mathematical calculations, in our empirical statements about, hands, planets, and existence in general.
Then he will proceed in the next section to analyze the grammar of our language-games to see if it can provide the rules required for that certainty, like the rules of calculation do. He distinguishes between an hypothesis, and a “logical proposition”. The “logical proposition” appears to be a statement of truth which may act as a premise in a logical argument, or a grammatical proposition in a language-game. When the truth of the premise is accepted there is no need for “I know…”, because acceptance eliminates doubt and serves the same purpose as “I know…”.
What we inherit is not a purely verbal transfer of information. The world-picture is inherited primarily through action:
The child learns to believe a host of things. I.e. it learns to act according to these beliefs. Bit by bit there forms a system of what is believed, and in that system some things stand unshakeably fast and some are more or less liable to shift. What stands fast does so, not because it is intrinsically obvious or convincing; it is rather held fast by what lies around it.
The inheritance isn’t just a set of facts (which, as you say, could be false); it is a trust in one’s teachers/parents and a way of acting that the child adopts. I don’t learn the ground is solid because my parents gave me a geology lesson; I inherited this hinge when I learned to walk with them.
We don’t learn the ground is solid as a “late-game” discovery; that certainty is “swallowed down” (143) the moment we begin to walk. The “entry requirement” isn’t a list of facts we memorise; it is the unquestioning certainty with which we act. This is precisely why hinges are not “established late”; they are the ground we previously “laid and sat on,” as you put it.
As I said previously, Wittgenstein uses the “logic of scientific investigations” to illustrate the logical structure of any and all human inquiry. He chooses scientific investigations because it represents the most rigorous form of investigation, but the same underlying principle applies to even our most basic daily inquiries.
Wittgenstein’s hinges include things like “I have two hands” or “The earth existed long ago” - certainties that are necessary for any human action, not just for professional science. Also, not all hinges are universal, e.g. “My name is…” may be a hinge for me and those who know me, but it is not a hinge for the rest of the world. The logic of the hinge remains the same regardless of the specific content.
This is a logical contradiction. How can a door “swing” if the hinges aren’t making the movement (i.e. questioning/doubt) possible? Wittgenstein is explicit:
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.
I agree that hinges “keep the door of our inquiry swinging.” But a door cannot “swing” before the hinges are fixed to the wall.
I don’t know what you mean by “the belief has no structure”.
Whether a child is told about brains or gods or spirits, they take these things on trust (see 159 again). Without this structure, the child couldn’t even “believe what it is told,” because belief requires a language-game. It is the act of ‘taking something on trust’ which is relevant, not the content of what is taken on trust.
The first 65 notes echo the discussion of certainty in Philosophical Investigation pt 2 section XI. The distinctions between psychology and logic which are made there apply in On Certainty as well. For instance when discussing knowing what is happening with other people:
Two points, however, are important: one, that in many cases some-one else cannot predict my actions, whereas I foresee them in my intentions; the other, that my prediction (in my expression of intention) has not the same foundation as his prediction of what I shall do, and the conclusions to be drawn from these predictions are quite different.
I can be as certain of someone else’s sensations as of any fact. But this does not make the propositions “He is much depressed”, “25 x 25 = 625” and “I am sixty years old” into similar instruments. The explanation suggests itself that the certainty is of a different kind.— This seems to point to a psychological difference. But the difference is logical.
“But, if you are certain, isn’t it that you are shutting your eyes in face of doubt?”—They are shut.
Am I less certain that this man is in pain than that twice two is four?—Does this shew the former to be mathematical certainty?——
‘Mathematical certainty’ is not a psychological concept.
The kind of certainty is the kind of language-game.
On the next page, Wittgenstein separates a “theory of knowledge” approach of scepticism from the viewpoint of language games:
We should sometimes like to call certainty and belief tones, colour-
ings, of thought; and it is true that they receive expression in the tone of voice. But do not think of them as ‘feelings’ which we have in speaking or thinking.
Ask, not: “What goes on in us when we are certain that .. . .?”— but: How is ‘the certainty that this is the case’ manifested in human action?
“While you can have complete certainty about someone else’s state of mind, still it is always merely subjective, not objective, certainty.”— These two words betoken a difference between language-games.
These observations underline how efforts to distinguish between language games is not a search for a substitute for what a “realist” like Moore is sure he has found.
We are talking passed each other. You are claiming that the unquestioning certainty with which we act is a hinge. Wittgenstein does not say this. He only mentions hinges twice: 1. scientific investigations 2. mathematics.
He does not identify “I have two hands” as a hinge. Why call it a hinge and not simply something that lies at the foundation of our lives? (see 448-449)
The truth of certain empirical propositions belongs to our frame of reference.
Two points to be noted. First, it is our frame of reference. It is not the frame of reference of a tribe of hunter-gathers even though they too have hands and walk on solid ground. Second, a door frame is not a hinge. The hinge is attached to the frame. A hinge cannot be understood apart from our frame of reference. The questions that we raise and our doubts are not the same as the questions and doubts of hunter gatherers.
The claim that Witt only mentions hinges twice, in connection with science and mathematics, in my mind is much too narrow. OC 341 says “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.” That’s a general statement about the structure of inquiry, not a claim restricted to science or mathematics. OC 342 specifies scientific investigations, but OC 341’s formulation covers “the questions that we raise and our doubts” without restriction to science. Whether 342 narrows 341 or illustrates it is precisely what’s at issue. But even on your reading, OC 343’s “If I want the door to turn, the hinges must stay put” is stated as a general principle, not one limited to scientific practices.
You’re right that Witt doesn’t place the word “hinge” next to “I have two hands.” But he doesn’t need to. The propositions he identifies as standing fast, as exempt from doubt, as forming the inherited background include hands (OC 1, 9, 32, 52), physical objects (OC 35-36), chairs and doors (OC 7), and the earth’s long existence. These are the propositions that function as hinges throughout the text. Restricting the concept to only the passages where the word explicitly appears ignores the functional role Witt describes.
On the frame of reference, you distinguish between our frame and that of hunter-gatherers, and claim that their questions and doubts are not the same as ours. That’s true for the scientific content. Hunter-gatherers don’t doubt whether water is H2O because the question doesn’t arise for them. But they share with us the certainty that hands exist, that the ground holds, that objects persist. Those certainties aren’t culturally specific. They’re presupposed by any human practice, scientific or otherwise. What varies between cultures is the content built on top of the bedrock. The bedrock itself is shared.
Your door frame analogy separates the frame from the hinges and makes hinges secondary. But in Witt’s metaphor, the hinges are what allow the door to turn. Without them the frame is inert. You ask why call these foundational certainties hinges rather than simply something at the foundation of our lives. Because Witt’s point is that they play the hinge role, ie., they are what our questions and doubts turn on. That’s not a label I’m imposing. It’s the function Witt describes.
Every major scholar of OC treats hinges as conditions that make epistemic practice possible, not as products of developed practices that arrive late.
Where I probably disagree with Luke is on the question of whether beliefs require language games. There are just to many beliefs that are expressed in our acts apart from language games.
It is a fact that these are the only places where he refers to them. To me this suggests that their role is limited. That we should not be inserting them at the foundations of human and animal life. That we should not regard countless things that we believe as hinges.
341 says “the questions we raise and our doubts”. 342: “it belongs to the logic of our scientific investigations”. 343 does not state a general principle, it says, “But it isn’t that the situation is like this …”
In their language-games I don’t think the certainty of having hands even arises. That is not to say that they are not certain of it, but rather that the problem of certainty does not come up. They simply use their hands. Certainty emerges in relation to the problem of radical doubt. It is part of our language-games:
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.
Moore’s propositions were part of his attempt to refute radical doubt. Radical doubt is a modern invention, having its origin in the quest for certainty and theories of mental representation such as that found in Descartes’ science. (See his work on optics.)
When Wittgenstein says “our scientific investigations” he is not just referring what scientists do. He does not say the investigations of scientists. It is our scientific investigations. Investigations that are part of our scientific form of life. It extends to and informs our questions, doubt, and certainty. It is part of our inherited background and world-picture which continues to be increasingly scientific and technological. It is a background not shared by hunter-gatherers or our pre-modern, pre-scientific ancestors.
Right. Our scientific world view extends far beyond scientific practices. Increasingly there is less and less in our lives that is not touched by science. It is strongly influenced by science spiritually, intellectually, and technologically, extending from energy to medicine to communications to transportation and beyond.
There is also Wittgenstein’s struggle against the pernicious problem of scientism.
It is rather that you assign the role of hinges to all kinds of things. Not even restricting them to propositions. On my reading, some things that are not doubted are hinges but others are not. It depends on the role the proposition plays in a language-game. We do not doubt that we have hands. We have no reason to. But their not being doubted is not sufficient for them to count as hinges. Particular things must turn on particular hinges.
No. They are parts of the same system - frame, hinge, door.
And the door won’t turn if it is not in the frame. Hinges are not free floating.
Round and round we go. Yes, our questions and doubts turn on hinges. Our disagreement is about what these hinges are. I have suggested that one way to distinguish a hinge is to look at what hangs on it. I have asked more than once how propositions about having hands play this role. Part of the problem is that, following Danièle Moyal-Sharrock, you ignore what Wittgenstein says and replace hinge propositions with hinge certainties.
I am well aware that this is not an orthodox reading but I think Wittgenstein would be opposed to interpretations governed by consensus.
You’ve restated your criterion that a hinge should be identifiable by what hangs on it. I’ve responded to this directly. The deepest hinges don’t support specific questions and doubts the way a premise supports a conclusion. Again and again, they make the practice of questioning possible. “I have two hands” doesn’t generate particular doubts that turn on it. It’s presupposed by any activity involving hands, which includes most of human life. Asking what specific doubts turn on it is like asking what specific weight a foundation supports at one particular point. The foundation holds the whole structure.
With regard to Moyal-Sharrock my use of “hinge certainty” comes from the four-sense taxonomy I’ve been developing in this thread, not from her non-propositional reading. I’m not denying that hinges can take propositional form. I’m identifying the kind of certainty they exhibit, which is distinct from subjective, epistemic, and absolute certainty. That’s a terminological choice in service of a specific interpretive framework, not a substitution of her vocabulary for Witt’s.
On orthodoxy, I didn’t cite the scholarship to argue from consensus. I cited it because your specific claims, that hinges are established late, that they’re scientifically shaped, that propositions like “I have two hands” don’t function as hinges, are at odds with the text. The scholarly agreement on this point isn’t the argument. The remarks are the argument. But when your reading contradicts the text and every major interpreter reads the text differently, at some point the burden falls on you to show where the text supports your position rather than simply asserting it’s unorthodox.
I am restating what a hinge does. It stays in place while things turn around it. Wittgenstein studied mechanical engineering. I think this picture is deliberate and should be understood by taking this analogy seriously.
I am well aware that this is not an orthodox reading but I think Wittgenstein would be opposed to interpretations governed by consensus.
Of course they don’t! The function of hinges is not to generate doubts but rather to move passed them. To allow the door to swing, that is, the inquiry to continue.
We do not presuppose that we have hands, we simply use them.
This is something an engineer can tell you. It is called a load calculation. A load calculation is required before a building permit is approved.
It is not the terminology, it is the claim that not all hinges are propositional.
It doesn’t. It contradicts your interpretation of the text.
That is what I have been doing. Where the text says “hinge propositions” I take this to mean that hinges are propositional.Where the text connects hinges and language-games I do not ignore that. Where he repeatedly says "our’ I take this to mean as opposed to other, that is, hinges are not universals that all questioning and doubting rely on. Where the text says:
That is to say, it belongs to the logic of our scientific investigations that certain things are in deed not doubted,
I take this seriously. I attempt to understand it. I do not attempt to ignore it on the assumption that all these other things are hinges.
You say the function of hinges is to allow inquiry to move past them, to allow the door to swing. You say we don’t presuppose we have hands, we simply use them. A certainty that inquiry moves past without question, that we act on without it ever arising as something to be established, that is what functioning as a hinge looks like. You’ve described the function and identified “I have two hands” as performing it. I’ll let that speak for itself.
Regarding Witt’s engineering background the question isn’t whether the analogy is deliberate. Of course it is. The question is what it shows. And on consensus, the issue was never orthodoxy. It was whether your claims have textual support. Witt would be equally opposed to using his name to authorize a reading that contradicts his text, because that’s what you’re doing PhD or not.
It is not the certainty that is moved past. It is the questions and doubts that impede understanding that must be overcome. They are roadblocks.
I am denying that this is a hinge. I have two hands does not perform the function of a hinge. The propositions that are exempt from doubt are not those that are subjectively certain.
Here you go:
There is no subjective sureness that I know something. The certainty is subjective, but not the knowledge.
So if I say “I know that I have two hands”, and that is not supposed to express just my subjective
certainty, I must be able to satisfy myself that I am right. But I can’t do that, for my having two
hands is not less certain before I have looked at them than afterwards. But I could say: “That I have
two hands is an irreversible belief.” That would express the fact that I am not ready to let anything
count as a disproof of this proposition.
‘Knowledge’ and ‘certainty’ belong to different categories …What interests us now is not being sure but knowledge. That is, we are interested in the fact
that about certain empirical propositions no doubt can exist if making judgments is to be possible at
all. Or again: I am inclined to believe that not everything that has the form of an empirical proposition is one.
I don’t see how you can draw this correlation between 63 and 65. 63 says that if the facts were different from what they are, then we would have different language-games. That’s a counterfactual proposal. But we know that it is the nature of “facts”, that they cannot change, so the counterfactual remains imaginary.
However, at 65 he talks about the reality of language-games actually changing. This cannot be a matter of the facts changing as mentioned in 63, because facts don’t change.
Therefore 63 and 65 are talking about two completely different things, the former being the need for language games to change if facts changed (which does not happen because facts don’t change), and the latter being the reality of language-games changing.
What we can conclude, is that language-games change as meaning and use changes, like you say, but we should make a further conclusion as well. If language-games, meaning and use, are based inf fact, then we’d have to conclude that facts change as well. But if we want to maintain the principle that facts do not change, then we must conclude that meaning and use are not based in fact.
So the issue is where are “facts” in all this? If frameworks are shifting and facts do not shift then the frameworks are not based in facts. And if they are not based in facts, then we have no claim to certainty.
Where do you find this thought expressed by Wittgenstein?
Consider some examples of when “facts” are discussed in On Certainty:
When someone has made sure, then he will go on to say, “Yes, the calculation is correct”, but he doesn’t draw this conclusion from the state of being certain. One does not infer matters of fact from one’s own certainty.
Certainty is as it were a tone of voice in which someone states facts, but one does not conclude from the tone of voice that he is justified.
If we imagine the facts otherwise than as they are, then certain language‐games lose some of their importance, others become important. And that’s how – gradually – the use of the vocabulary of language changes.
I am told, for example, that many years ago, someone climbed this mountain. Do I always investigate the trustworthiness of the narrator and whether the mountain has existed for years? The child learns that there are trustworthy and untrustworthy narrators much later than he learns facts he is told. He doesn’t learn that this mountain has existed for ages at all; that is, the question whether it is so doesn’t arise. He, so to speak, swallows down this consequence together with what he learns.
As children we learn facts, for example that every human being has a brain, and we accept them on faith. I believe that there is an island, Australia, which has such‐and‐such a shape, and so on and so forth, I believe I had great‐grandparents, that the people who professed to be my parents really were my parents, and so on. This faith may never be expressed, indeed the thought that things are so may never cross my mind.
In general, I take what is in textbooks, for example, of geography, to be true. Why? I say: all these facts have been confirmed a hundred times over. But how do I know that? What’s my evidence for it? I have a world‐picture. Is it true or false? It is first and foremost the substrate of all my enquiring and asserting. The propositions describing it are not all equally subject to checking.
I believe what people communicate to me in a certain way. That’s the way I come to believe geographical, chemical, historical facts, etc. That’s the way I learn the sciences. Of course, learning rests on believing.> Someone who has learnt that Mont Blanc is 4,000 metres high, who has looked it up on the map, now says that he knows this.
And can one now say: we accord our trust in this way, because it has proved successful?
If everything speaks for a hypothesis, and nothing against it – is it then certainly true? One may call it thus. – But is it certain that it agrees with reality, with the facts? Once you have asked this question you are already going round in a circle.
The reason why the use of ‘true or false’ is somewhat misleading is this: it is as if one were saying, “it either agrees with the facts or it doesn’t”, while the very question at stake is what ‘agreement’ is here.
“We could doubt every single one of these facts, but we couldn’t doubt them all.”
Wouldn’t it be more correct to say: “We don’t doubt them all”?
Our not doubting them all just is our way of judging and so of acting.
If someone said “The Earth has not existed for long” – what would he be challenging? Do I know?
Does it have to be what is called a scientific belief? Couldn’t it be a mystical one? Must he necessarily be contradicting historical facts? Or even geographical ones?
Number 191 sounds like a sharp challenge to you saying: "we know that it is the nature of “facts”, that they cannot change.
That doesn’t make any significant difference to the point I made. If “facts” are the type of things which change with shifting language-games, then they are not the type of thing which are responsible for certainty.
That’s the thing, either way you look at it, facts and certainty end up as unrelated. We can say, as I said, and people commonly say, that “facts” are what constitutes unchanging truth, in which case they are unrelated to the shifting and changing language-games where we are supposed to find certainty. Or we can say, as you say Wittgenstein indicates, that facts shift and change with the language-games. But if the facts are shifting and changing then this is not what supports certainty. In neither case can we relate certainty to facts. The former has the problem of a gap between the language-games and the facts, so certainty isn’t supported. The latter has facts changing, so certainty isn’t supported.
I’d say the opposite. Out of all your quotes, 191 supports what I said the best. But it really doesn’t matter in what sense you take “fact”, what is demonstrated at 63/65 is that there is a gap between “fact” and “certainty” no matter how you look at it.