Excerpts from On Certainty
1. If you do know that here is one hand, we'll grant you all the rest. When one says that such and such a proposition can't be proved, of course that does not mean that it can't be derived from other propositions; any proposition can be derived from other ones. But they may be no more certain than it is itself. (On this a curious remark by H. Newman.)
2. From its seeming to me-or to everyone-to be so, it doesn't follow that it is so. What we can ask is whether it can make sense to doubt it.
3. If e.g. someone says "I don't know if there's a hand here" he might be told "Look closer". This possibility of satisfying oneself is part of the language-game. Is one of its essential features.
4. "I know that I am a human being." In order to see how unclear the sense of this proposition is, consider its negation. At most it might be taken to mean "I know I have the organs of a human." (E.g. a brain, which, after all, no one has ever yet seen.) But what about such a proposition as "I know I have a brain"? Can I doubt it? Grounds for doubt are lacking! Everything speaks in its favour, nothing against it. Nevertheless it is imaginable that my skull should turn out empty when it was operated on.
5. Whether a proposition can turn out false after all depends on what I make count as determinants for that proposition.
6. Now, can one enumerate what one knows (like Moore)? Straight off like that, I believe not. For otherwise the expression "I know" gets misused. And through this misuse a queer and extremely important mental state seems to be revealed.
7. My life shews that I know or am certain that there is a chair over there, or a door, and so on. I tell a friend e.g. "Take that chair over there", "Shut the door", etc. etc.
8. The difference between the concept of 'knowing' and the concept of 'being certain' isn't of any great importance at all, except where "I know" is meant to mean: I can't be wrong. In a law-court, for example, "I am certain" could replace "I know" in every piece of testimony. We might even imagine its being forbidden to say "I know" there. [A passage in Wilhelm Meister, where "You know" or "You knew" is used in the sense "You were certain", the facts being different from what he knew.]
9. Now do I, in the course of my life, make sure I know that here is a hand-my own hand, that is?
11. We just do not see how very specialized the use of "I know" is.
12. For "I know" seems to describe a state of affairs which guarantees what is known, guarantees it as a fact. One always forgets the expression "I thought I knew".
13. For it is not as though the proposition "It is so" could be inferred from someone else's utterance: "I know it is so". Nor from the utterance together with its not being a lie. But can't I infer "It is so" from my own utterance "I know etc."? Yes; and also "There is a hand there" follows from the proposition "He knows that there's a hand there". But from his utterance "I know..." it does not follow that he does know it.
14. That he does know takes some shewing.
15. It needs to be shewn that no mistake was possible. Giving the assurance "I know" doesn't suffice. For it is after all only an assurance that I can't be making a mistake, and it needs to be objectively established that I am not making a mistake about that.
16. "If I know something, then I also know that I know it etc." amounts to: "I know that" means "I am incapable of being wrong about that". But whether I am so needs to be established objectively.
17. Suppose now I said "I'm incapable of being wrong about this: that is a book" while I point to an object. What would a mistake here be like? And have I any clear idea of it?
22. It would surely be remarkable if we had to believe the reliable person who says "I can't be wrong"; or who says "I am not wrong".
25. One may be wrong even about "there being a hand there". Only in particular circumstances is it impossible. "Even in a calculation one can be wrong-only in certain circumstances one can't".
26. But can it be seen from a rule what circumstances logically exclude a mistake in the employment of rules of calculation? What use is a rule to us here? Mightn't we (in turn) go wrong in applying it?
29. Practice in the use of the rule also shews what is a mistake in its employment.
31. The propositions which one comes back to again and again as if bewitched-these I should like to expunge from philosophical language.
33. Thus we expunge the sentences that don't get us any further.
35. But can't it be imagined that there should be no physical objects? I don't know. And yet, "There are physical objects" is nonsense. Is it supposed to be an empirical proposition? And is this an empirical proposition: "There seem to be physical objects"?
36. "A is a physical object" is a piece of instruction which we give only to someone who doesn't yet understand either what "A" means or what "physical objects" means. Thus it is instruction about the use of words, and "physical object" is a logical concept. (Like colour, quality, ...) And that is why no such proposition as: "there are physical objects" can be formulated. Yet we encounter such unsuccessful shots at every turn.
38. Knowledge in mathematics: Here one has to keep on reminding oneself of the unimportance of the 'inner process' or 'state' and ask "Why should it be important? What does it matter to me?" What is interesting is how we use mathematical propositions.
39. This is how calculation is done, in such circumstances a calculation is treated as absolutely reliable, as certainly correct.
41. "I know where I am feeling pain", "I know that I feel it here" is as wrong as "I know that I am in pain". But "I know where you touched my arm" is right.
43. What sort of proposition is this: "We cannot have miscalculated in 12x12=144"? It must surely be a proposition of logic. But now, is it not the same, or doesn't it come to the same, as the statement 12x12=144?
44. If you demand a rule from which it follows that there can't have been a miscalculation here, the answer is that we did not learn this through a rule, but by learning to calculate.
45. We got to know the nature of calculating by learning to calculate.
47. This is how one calculates. Calculating is this. What we learn at school, for example. Forget this transcendent certainty, which is connected with your concept of spirit.
49. But remember: even when the calculation is something fixed for me, this is only a decision for a practical purpose.
50. When does one say, I know that...x...=...? When one has checked the calculation.
53. So one might grant that Moore was right, if he is interpreted like this: a proposition saying that here is a physical object may have the same logical status as one saying that here is a red patch.
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?
59. "I know" is here a logical insight. Only realism can't be proved by means of it.
61. ...A meaning of a word is a kind of employment of it. For it is what we learn when the word is incorporated into our language.
62. That is why there exists a correspondence between the concept 'rule' and 'meaning'.
63. If we imagine the facts otherwise than as they are, certain language-games lose some of their importance, while others become important. And in this way there is an alteration-a gradual one-in the use of the vocabulary of a language.
64. Compare the meaning of a word with the 'function' of an official. And 'different meanings' with 'different functions'.
65. When language-games change, then there is a change in concepts, and with the concepts the meanings of words change.
68. The question is: what is the logician to say here?
71. If my friend were to imagine one day that he had been living for a long time past in such and such a place, etc. etc., I should not call this a mistake, but rather a mental disturbance, perhaps a transient one.
72. Not every false belief of this sort is a mistake.
73. But what is the difference between mistake and mental disturbance? Or what is the difference between my treating it as a mistake and my treating it as mental disturbance?
74. Can we say: a mistake doesn't only have a cause, it also has a ground? I.e. roughly: when someone makes a mistake, this can be fitted into what he knows aright.
76. Naturally, my aim must be to say what the statements one would like to make here, but cannot make significantly.
79. That I am a man and not a woman can be verified, but if I were to say I was a woman, and then tried to explain the error by saying I hadn't checked the statement, the explanation would not be accepted.
80. The truth of my statements is the test of my understanding of these statements.
81. That is to say: if I make certain false statements, it becomes uncertain whether I understand them.
82. What counts as an adequate test of a statement belongs to logic. It belongs to the description of the language-game.
83. The truth of certain empirical propositions belongs to our frame of reference.
86. Suppose I replaced Moore's "I know" by "I am of the unshakeable conviction"?
94. But I did not get my picture of the world by satisfying myself of its correctness; nor do I have it because I am satisfied of its correctness. No: it is the inherited background against which I distinguish between true and false.
96. It might be imagined that some propositions, of the form of empirical propositions, were hardened and functioned as channels for such empirical propositions as were not hardened but fluid; and that this relation altered with time, in that fluid propositions hardened, and hard ones became fluid.
97. The mythology may change back into a state of flux, the river-bed of thoughts may shift. But I distinguish between the movement of the waters on the river-bed and the shift of the bed itself; though there is no sharp division of the one from the other.
99. And the bank of that river consists partly of hard rock, subject to no alteration or only to an imperceptible one, partly of sand, which now in one place now in another gets washed away, or deposited.
100. The truths which Moore says he knows, are such as, roughly speaking, all of us know, if he knows them.
101. Such a proposition might be e.g. "My body has never disappeared and reappeared again after an interval."
104. I am for example also convinced that the sun is not a hole in the vault of heaven.
107. Isn't it altogether like the way one can instruct a child to believe in a God, or that none exists, and it will accordingly be able to produce apparently telling grounds for the one or the other?
109. "An empirical proposition can be tested" (we say). But how? and through what?
110. What counts as its test? "But is this an adequate test? And, if so, must it not be recognizable as such in logic?" As if giving grounds did not come to an end sometime. But the end is not an ungrounded presupposition: it is an ungrounded way of acting.
112. And isn't that what Moore wants to say, when he says he knows all these things? But is his knowing it really what is in question, and not rather that some of these propositions must be solid for us?
113. When someone is trying to teach us mathematics, he will not begin by assuring us that he knows that a+b = b+a.
114. If you are not certain of any fact, you cannot be certain of the meaning of your words either.
115. If you tried to doubt everything you would not get as far as doubting anything. the game of doubting itself presupposes certainty.
116. Instead of "I know...", couldn't Moore have said: "It stands fast for me that..."? And further: "It stands fast for me and many others..."
118. Now would it be correct to say: So far no one has opened my skull in order to see whether there is a brain inside; but everything speaks for, and nothing against, its being what they would find there?
119. But can't it also be said: Everything speaks for, and nothing against the table's still being there when no one sees it? For what does speak for it?
120. But if anyone were to doubt it, how would his doubt come out in practice? And couldn't we peacefully leave him to doubt it, since it makes no difference at all?
121. Can one say: "where there is no doubt there is no knowledge either"?
122. Doesn't one need grounds for doubting?
123. Wherever I look, I found no ground for doubting that...
124. I want to say: We use judgements as principles of judgement.
126. I am not more certain of the meaning of my words than I am of certain judgements. Can I doubt that this colour is called "blue"? (My) doubts form a system.
127. For how do I know that someone is in doubt? How do I know that he uses the words "I doubt it" as I do?
128. From a child up I learnt to judge like this. This is judging.
129. This is how I learned to judge; this I got to know as judgement.
131. No, experience is not the ground for our game of judging. Nor is its outstanding success.
132. Men have judged that a king can make rain; we say this contradicts all experience. Today they judge that aeroplanes and the radio etc. are means for the closer contact of peoples and the spread of culture.
139. Not only rules, but also examples are needed for establishing a practice. Our rules leave loop-holes open, and the practice has to speak for itself.
141. When we first begin to believe anything, what we believe is not a single proposition, it is a whole system of propositions. (Light dawns gradually over the whole.)
142. It is not single axioms that strike me as obvious, it is a system in which consequesnces and premises give one another mutual support.
147. The picture of the earth as a ball is a good picture, it proves itself everywhere, it is also a simple picture-in short, we work with it without doubting it.
148. Why do I not satisfy myself that I have two feet when I want to get up from a chair? There is no why. I simply don't. This is how I act.
149. My judgements themselves characterize the way I judge, characterize the nature of judgement.
151. I should like to say: Moore does not know what he asserts he knows, but it stands fast for him, as also for me; regarding it as absolutely solid is part of our method of doubt and enquiry.
156. In order to make a mistake, a man must already judge in conformity with mankind.
157. Suppose a man could not remember whether he had always had five fingers or two hands? Should we understand him? Could we be sure of understanding him?
160. The child learns by believing the adult. Doubt comes after belief.
161. I learned an enourmous amount and accepted it on human authority, and then I found some things confirmed or disconfirmed by my own experience.
164. Doesn't testing come to an end?
166. The difficulty is to realize the groundlessness of our believing.
174. I act with complete certainty. But this certainty is my own.
177. What I know, I believe.
179. It would be correct to say: "I believe..." has subjective truth; but "I know..." not.
180. Or again "I believe..." is an 'expression', but not "I know..."
181. Suppose Moore had said "I swear..." instead of "I know...".
183. "It is certain that after the battle of Austerlitz Napoleon... Well, in that case it's surely also certain that the earth existed then."
189. At some point one has to pass from explanation to mere description.
192. To be sure there is justification; but justification comes to an end.
193. What does this mean: the truth of a proposition is certain?
197. It would be nonsense to say that we regard something as sure evidence because it is certainly true.
198. Rather, we must first determine the role of deciding for or against a proposition.
201. Suppose someone were to ask: "Is it really right for us to rely on the evidence of our memory (or our senses) as we do?"
202. Moore's certain propositions almost declare that we have a right to rely on this evidence.
204. Giving grounds, however, justifying the evidence, comes to an end; but the end is not certain propositions' striking us immediately as true, i.e. it is not a kind of seeing on our part; it is our acting, which lies at the bottom of the language-game.
205. If the true is what is grounded, then the ground is not true, nor yet false.
207. "Strange coincidence, that every man whose skull has been opened had a brain!"
209. The existence of the earth is rather part of the whole picture which forms the starting-point of belief for me.
210. Does my telephone call to New York strengthen my conviction that the earth exists? Much seems to be fixed, and it is removed from the traffic. It is so to speak shunted onto an unused siding.
213. Our 'empirical propositions' do not form a homogeneous mass.
215. Here we see that the idea 'agreement with reality' does not have any clear application.
218. Can I believe for one moment that I have ever been in the stratosphere? No. So do I know the contrary, like Moore?
219. There cannot be any doubt about it for me as a reasonable person. That's it.
220. The reasonable man does not have certain doubts.
221. Can I be in doubt at will?
222. I cannot possibly doubt that I was never in the stratosphere. Does that make me know it? Does it make it true?
223. For mightn't I be crazy and not doubting what I absolutely ought to doubt?
225. What I hold fast to is not one proposition but a nest of propositions.
229. Our talk gets its meaning from the rest of our proceedings.
235. And that something stands fast for me is not grounded in my stupidity or credulity.
248. I have arrived at the rock bottom of my convictions. And one might almost say that these foundation-walls are carried by the whole house.
250 My having two hands is, in normal circumstances, as certain as anything that I could produce in evidence for it. That is why I am not in a position to take the sight of my hand as evidence for it.
253. At the foundation of well-founded belief lies belief that is not founded.
254. Any reasonable person behaves like this.
256. On the other hand a language-game does change with time.
260. I would like to reserve the expression "I know" for the cases in which it is used in normal linguistic exchange.
263. The schoolboy believes his teachers and his schoolbooks.
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.
344. My life consists in my being content to accept many things.
354. Doubting and non-doubting behavior. There is the first only if there is the second.
358. Now I would like to regard this certainty, not as something akin to hastiness or superficiality, but as a form of life. (That is very badly expressed and probably badly thought as well.)
448. Something must be taught us as a foundation.
458. One doubts on specific grounds. The question is this: how is doubt introduced into the language-game?
471. It is so difficult to find the beginning. Or better: it is difficult to begin at the beginning. And not try to go further back.
579. It is part of the language-game with people's names that everyone knows his name with the greatest certainty.
2. From its seeming to me-or to everyone-to be so, it doesn't follow that it is so. What we can ask is whether it can make sense to doubt it.
3. If e.g. someone says "I don't know if there's a hand here" he might be told "Look closer". This possibility of satisfying oneself is part of the language-game. Is one of its essential features.
4. "I know that I am a human being." In order to see how unclear the sense of this proposition is, consider its negation. At most it might be taken to mean "I know I have the organs of a human." (E.g. a brain, which, after all, no one has ever yet seen.) But what about such a proposition as "I know I have a brain"? Can I doubt it? Grounds for doubt are lacking! Everything speaks in its favour, nothing against it. Nevertheless it is imaginable that my skull should turn out empty when it was operated on.
5. Whether a proposition can turn out false after all depends on what I make count as determinants for that proposition.
6. Now, can one enumerate what one knows (like Moore)? Straight off like that, I believe not. For otherwise the expression "I know" gets misused. And through this misuse a queer and extremely important mental state seems to be revealed.
7. My life shews that I know or am certain that there is a chair over there, or a door, and so on. I tell a friend e.g. "Take that chair over there", "Shut the door", etc. etc.
8. The difference between the concept of 'knowing' and the concept of 'being certain' isn't of any great importance at all, except where "I know" is meant to mean: I can't be wrong. In a law-court, for example, "I am certain" could replace "I know" in every piece of testimony. We might even imagine its being forbidden to say "I know" there. [A passage in Wilhelm Meister, where "You know" or "You knew" is used in the sense "You were certain", the facts being different from what he knew.]
9. Now do I, in the course of my life, make sure I know that here is a hand-my own hand, that is?
11. We just do not see how very specialized the use of "I know" is.
12. For "I know" seems to describe a state of affairs which guarantees what is known, guarantees it as a fact. One always forgets the expression "I thought I knew".
13. For it is not as though the proposition "It is so" could be inferred from someone else's utterance: "I know it is so". Nor from the utterance together with its not being a lie. But can't I infer "It is so" from my own utterance "I know etc."? Yes; and also "There is a hand there" follows from the proposition "He knows that there's a hand there". But from his utterance "I know..." it does not follow that he does know it.
14. That he does know takes some shewing.
15. It needs to be shewn that no mistake was possible. Giving the assurance "I know" doesn't suffice. For it is after all only an assurance that I can't be making a mistake, and it needs to be objectively established that I am not making a mistake about that.
16. "If I know something, then I also know that I know it etc." amounts to: "I know that" means "I am incapable of being wrong about that". But whether I am so needs to be established objectively.
17. Suppose now I said "I'm incapable of being wrong about this: that is a book" while I point to an object. What would a mistake here be like? And have I any clear idea of it?
22. It would surely be remarkable if we had to believe the reliable person who says "I can't be wrong"; or who says "I am not wrong".
25. One may be wrong even about "there being a hand there". Only in particular circumstances is it impossible. "Even in a calculation one can be wrong-only in certain circumstances one can't".
26. But can it be seen from a rule what circumstances logically exclude a mistake in the employment of rules of calculation? What use is a rule to us here? Mightn't we (in turn) go wrong in applying it?
29. Practice in the use of the rule also shews what is a mistake in its employment.
31. The propositions which one comes back to again and again as if bewitched-these I should like to expunge from philosophical language.
33. Thus we expunge the sentences that don't get us any further.
35. But can't it be imagined that there should be no physical objects? I don't know. And yet, "There are physical objects" is nonsense. Is it supposed to be an empirical proposition? And is this an empirical proposition: "There seem to be physical objects"?
36. "A is a physical object" is a piece of instruction which we give only to someone who doesn't yet understand either what "A" means or what "physical objects" means. Thus it is instruction about the use of words, and "physical object" is a logical concept. (Like colour, quality, ...) And that is why no such proposition as: "there are physical objects" can be formulated. Yet we encounter such unsuccessful shots at every turn.
38. Knowledge in mathematics: Here one has to keep on reminding oneself of the unimportance of the 'inner process' or 'state' and ask "Why should it be important? What does it matter to me?" What is interesting is how we use mathematical propositions.
39. This is how calculation is done, in such circumstances a calculation is treated as absolutely reliable, as certainly correct.
41. "I know where I am feeling pain", "I know that I feel it here" is as wrong as "I know that I am in pain". But "I know where you touched my arm" is right.
43. What sort of proposition is this: "We cannot have miscalculated in 12x12=144"? It must surely be a proposition of logic. But now, is it not the same, or doesn't it come to the same, as the statement 12x12=144?
44. If you demand a rule from which it follows that there can't have been a miscalculation here, the answer is that we did not learn this through a rule, but by learning to calculate.
45. We got to know the nature of calculating by learning to calculate.
47. This is how one calculates. Calculating is this. What we learn at school, for example. Forget this transcendent certainty, which is connected with your concept of spirit.
49. But remember: even when the calculation is something fixed for me, this is only a decision for a practical purpose.
50. When does one say, I know that...x...=...? When one has checked the calculation.
53. So one might grant that Moore was right, if he is interpreted like this: a proposition saying that here is a physical object may have the same logical status as one saying that here is a red patch.
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?
59. "I know" is here a logical insight. Only realism can't be proved by means of it.
61. ...A meaning of a word is a kind of employment of it. For it is what we learn when the word is incorporated into our language.
62. That is why there exists a correspondence between the concept 'rule' and 'meaning'.
63. If we imagine the facts otherwise than as they are, certain language-games lose some of their importance, while others become important. And in this way there is an alteration-a gradual one-in the use of the vocabulary of a language.
64. Compare the meaning of a word with the 'function' of an official. And 'different meanings' with 'different functions'.
65. When language-games change, then there is a change in concepts, and with the concepts the meanings of words change.
68. The question is: what is the logician to say here?
71. If my friend were to imagine one day that he had been living for a long time past in such and such a place, etc. etc., I should not call this a mistake, but rather a mental disturbance, perhaps a transient one.
72. Not every false belief of this sort is a mistake.
73. But what is the difference between mistake and mental disturbance? Or what is the difference between my treating it as a mistake and my treating it as mental disturbance?
74. Can we say: a mistake doesn't only have a cause, it also has a ground? I.e. roughly: when someone makes a mistake, this can be fitted into what he knows aright.
76. Naturally, my aim must be to say what the statements one would like to make here, but cannot make significantly.
79. That I am a man and not a woman can be verified, but if I were to say I was a woman, and then tried to explain the error by saying I hadn't checked the statement, the explanation would not be accepted.
80. The truth of my statements is the test of my understanding of these statements.
81. That is to say: if I make certain false statements, it becomes uncertain whether I understand them.
82. What counts as an adequate test of a statement belongs to logic. It belongs to the description of the language-game.
83. The truth of certain empirical propositions belongs to our frame of reference.
86. Suppose I replaced Moore's "I know" by "I am of the unshakeable conviction"?
94. But I did not get my picture of the world by satisfying myself of its correctness; nor do I have it because I am satisfied of its correctness. No: it is the inherited background against which I distinguish between true and false.
96. It might be imagined that some propositions, of the form of empirical propositions, were hardened and functioned as channels for such empirical propositions as were not hardened but fluid; and that this relation altered with time, in that fluid propositions hardened, and hard ones became fluid.
97. The mythology may change back into a state of flux, the river-bed of thoughts may shift. But I distinguish between the movement of the waters on the river-bed and the shift of the bed itself; though there is no sharp division of the one from the other.
99. And the bank of that river consists partly of hard rock, subject to no alteration or only to an imperceptible one, partly of sand, which now in one place now in another gets washed away, or deposited.
100. The truths which Moore says he knows, are such as, roughly speaking, all of us know, if he knows them.
101. Such a proposition might be e.g. "My body has never disappeared and reappeared again after an interval."
104. I am for example also convinced that the sun is not a hole in the vault of heaven.
107. Isn't it altogether like the way one can instruct a child to believe in a God, or that none exists, and it will accordingly be able to produce apparently telling grounds for the one or the other?
109. "An empirical proposition can be tested" (we say). But how? and through what?
110. What counts as its test? "But is this an adequate test? And, if so, must it not be recognizable as such in logic?" As if giving grounds did not come to an end sometime. But the end is not an ungrounded presupposition: it is an ungrounded way of acting.
112. And isn't that what Moore wants to say, when he says he knows all these things? But is his knowing it really what is in question, and not rather that some of these propositions must be solid for us?
113. When someone is trying to teach us mathematics, he will not begin by assuring us that he knows that a+b = b+a.
114. If you are not certain of any fact, you cannot be certain of the meaning of your words either.
115. If you tried to doubt everything you would not get as far as doubting anything. the game of doubting itself presupposes certainty.
116. Instead of "I know...", couldn't Moore have said: "It stands fast for me that..."? And further: "It stands fast for me and many others..."
118. Now would it be correct to say: So far no one has opened my skull in order to see whether there is a brain inside; but everything speaks for, and nothing against, its being what they would find there?
119. But can't it also be said: Everything speaks for, and nothing against the table's still being there when no one sees it? For what does speak for it?
120. But if anyone were to doubt it, how would his doubt come out in practice? And couldn't we peacefully leave him to doubt it, since it makes no difference at all?
121. Can one say: "where there is no doubt there is no knowledge either"?
122. Doesn't one need grounds for doubting?
123. Wherever I look, I found no ground for doubting that...
124. I want to say: We use judgements as principles of judgement.
126. I am not more certain of the meaning of my words than I am of certain judgements. Can I doubt that this colour is called "blue"? (My) doubts form a system.
127. For how do I know that someone is in doubt? How do I know that he uses the words "I doubt it" as I do?
128. From a child up I learnt to judge like this. This is judging.
129. This is how I learned to judge; this I got to know as judgement.
131. No, experience is not the ground for our game of judging. Nor is its outstanding success.
132. Men have judged that a king can make rain; we say this contradicts all experience. Today they judge that aeroplanes and the radio etc. are means for the closer contact of peoples and the spread of culture.
139. Not only rules, but also examples are needed for establishing a practice. Our rules leave loop-holes open, and the practice has to speak for itself.
141. When we first begin to believe anything, what we believe is not a single proposition, it is a whole system of propositions. (Light dawns gradually over the whole.)
142. It is not single axioms that strike me as obvious, it is a system in which consequesnces and premises give one another mutual support.
147. The picture of the earth as a ball is a good picture, it proves itself everywhere, it is also a simple picture-in short, we work with it without doubting it.
148. Why do I not satisfy myself that I have two feet when I want to get up from a chair? There is no why. I simply don't. This is how I act.
149. My judgements themselves characterize the way I judge, characterize the nature of judgement.
151. I should like to say: Moore does not know what he asserts he knows, but it stands fast for him, as also for me; regarding it as absolutely solid is part of our method of doubt and enquiry.
156. In order to make a mistake, a man must already judge in conformity with mankind.
157. Suppose a man could not remember whether he had always had five fingers or two hands? Should we understand him? Could we be sure of understanding him?
160. The child learns by believing the adult. Doubt comes after belief.
161. I learned an enourmous amount and accepted it on human authority, and then I found some things confirmed or disconfirmed by my own experience.
164. Doesn't testing come to an end?
166. The difficulty is to realize the groundlessness of our believing.
174. I act with complete certainty. But this certainty is my own.
177. What I know, I believe.
179. It would be correct to say: "I believe..." has subjective truth; but "I know..." not.
180. Or again "I believe..." is an 'expression', but not "I know..."
181. Suppose Moore had said "I swear..." instead of "I know...".
183. "It is certain that after the battle of Austerlitz Napoleon... Well, in that case it's surely also certain that the earth existed then."
189. At some point one has to pass from explanation to mere description.
192. To be sure there is justification; but justification comes to an end.
193. What does this mean: the truth of a proposition is certain?
197. It would be nonsense to say that we regard something as sure evidence because it is certainly true.
198. Rather, we must first determine the role of deciding for or against a proposition.
201. Suppose someone were to ask: "Is it really right for us to rely on the evidence of our memory (or our senses) as we do?"
202. Moore's certain propositions almost declare that we have a right to rely on this evidence.
204. Giving grounds, however, justifying the evidence, comes to an end; but the end is not certain propositions' striking us immediately as true, i.e. it is not a kind of seeing on our part; it is our acting, which lies at the bottom of the language-game.
205. If the true is what is grounded, then the ground is not true, nor yet false.
207. "Strange coincidence, that every man whose skull has been opened had a brain!"
209. The existence of the earth is rather part of the whole picture which forms the starting-point of belief for me.
210. Does my telephone call to New York strengthen my conviction that the earth exists? Much seems to be fixed, and it is removed from the traffic. It is so to speak shunted onto an unused siding.
213. Our 'empirical propositions' do not form a homogeneous mass.
215. Here we see that the idea 'agreement with reality' does not have any clear application.
218. Can I believe for one moment that I have ever been in the stratosphere? No. So do I know the contrary, like Moore?
219. There cannot be any doubt about it for me as a reasonable person. That's it.
220. The reasonable man does not have certain doubts.
221. Can I be in doubt at will?
222. I cannot possibly doubt that I was never in the stratosphere. Does that make me know it? Does it make it true?
223. For mightn't I be crazy and not doubting what I absolutely ought to doubt?
225. What I hold fast to is not one proposition but a nest of propositions.
229. Our talk gets its meaning from the rest of our proceedings.
235. And that something stands fast for me is not grounded in my stupidity or credulity.
248. I have arrived at the rock bottom of my convictions. And one might almost say that these foundation-walls are carried by the whole house.
250 My having two hands is, in normal circumstances, as certain as anything that I could produce in evidence for it. That is why I am not in a position to take the sight of my hand as evidence for it.
253. At the foundation of well-founded belief lies belief that is not founded.
254. Any reasonable person behaves like this.
256. On the other hand a language-game does change with time.
260. I would like to reserve the expression "I know" for the cases in which it is used in normal linguistic exchange.
263. The schoolboy believes his teachers and his schoolbooks.
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.
344. My life consists in my being content to accept many things.
354. Doubting and non-doubting behavior. There is the first only if there is the second.
358. Now I would like to regard this certainty, not as something akin to hastiness or superficiality, but as a form of life. (That is very badly expressed and probably badly thought as well.)
448. Something must be taught us as a foundation.
458. One doubts on specific grounds. The question is this: how is doubt introduced into the language-game?
471. It is so difficult to find the beginning. Or better: it is difficult to begin at the beginning. And not try to go further back.
579. It is part of the language-game with people's names that everyone knows his name with the greatest certainty.