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All the ideas for 'Lectures 1930-32 (student notes)', 'Truth and Predication' and 'A Priori Knowledge Revisited'

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71 ideas

1. Philosophy / C. History of Philosophy / 1. History of Philosophy
The history of philosophy only matters if the subject is a choice between rival theories [Wittgenstein]
     Full Idea: If philosophy were a matter of choice between rival theories, then it would be sound to teach it historically. But if it is not, then it is a fault to teach it historically, because it is quite unnecessary; we can tackle the subject direct.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V A)
     A reaction: Wittgenstein was a bit notorious for not knowing the history of the subject terribly well, and this explains why. Presumably our tackling the subject direct will not have the dreadful consequence of producing yet another theory.
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
Philosophy tries to be rid of certain intellectual puzzles, irrelevant to daily life [Wittgenstein]
     Full Idea: Philosophy is the attempt to be rid of a particular kind of puzzlement. This 'philosophical' puzzlement is one of the intellect and not of instinct. Philosophical puzzles are irrelevant to our every-day life.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.1)
     A reaction: All enquiry begins with puzzles, and they are cured by explanations, which result in understanding. In that sense he is right. I entirely disagree that the puzzles are irrelevant to daily life.
1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophers express puzzlement, but don't clearly state the puzzle [Wittgenstein]
     Full Idea: Philosophers as 'Why?' and 'What?' without knowing clearly what their questions are. They are expressing a feeling of mental uneasiness.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.1)
     A reaction: He suggests it is childish to express puzzlement, instead of asking for precise information. How odd. All enquiries start with vague puzzlement, which gradually comes into focus, or else is abandoned.
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
We don't need a theory of truth, because we use the word perfectly well [Wittgenstein]
     Full Idea: It is nonsense to try to find a theory of truth, because we can see that in everyday life we use the word quite clearly and definitely in various different senses.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B)
     A reaction: This was a year before Tarski published his famous theory of truth for formal languages. Prior to that, most philosophers were giving up on truth. Would he say the same about 'gravity' or 'inflation'?
1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
We already know what we want to know, and analysis gives us no new facts [Wittgenstein]
     Full Idea: In philosophy we know already all that we want to know; philosophical analysis does not give us any new facts.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B V.1)
2. Reason / F. Fallacies / 8. Category Mistake / a. Category mistakes
Words of the same kind can be substituted in a proposition without producing nonsense [Wittgenstein]
     Full Idea: 'Blue' and 'brown' are of the same kind, for the substitution of one for the other, though it may falsify the proposition, does not make nonsense of it.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4)
     A reaction: He chooses an easy example, because they are determinates of the determinable 'coloured'. What if I say 'the sky is blue', and then substitute 'frightening' for 'blue'?
2. Reason / F. Fallacies / 8. Category Mistake / b. Category mistake as syntactic
Talking nonsense is not following the rules [Wittgenstein]
     Full Idea: Talking nonsense is not following the rules.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C X)
     A reaction: He doesn't seem to distinguish between syntax and semantics, and makes it sound as if all nonsense is syntactic, which it isn't.
Grammar says that saying 'sound is red' is not false, but nonsense [Wittgenstein]
     Full Idea: If grammar says that you cannot say that a sound is red, it means not that it is false to say so but that it is nonsense - i.e. not a language at all.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B IX.6)
     A reaction: I am baffled as to why he thinks 'grammar' is what prohibits such a statement. Surely the world, the nature of sound and colour, is what makes the application of the predicate wrong. Sounds aren't coloured, so they can't be red. False, not nonsense.
3. Truth / A. Truth Problems / 2. Defining Truth
There is no theory of truth, because it isn't a concept [Wittgenstein]
     Full Idea: It is wrong to say that there is any one theory of truth, for truth is not a concept.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B)
     A reaction: This makes you wonder how he understood the word 'concept'. In most modern discussions truth seems to be a concept, and in Frege it can be an unsaturated predicate which is satisfied by sentences or thoughts.
A comprehensive theory of truth probably includes a theory of predication [Davidson]
     Full Idea: Theories of truth and theories of predication are closely related: it seems probable that any comprehensive theory of truth will include a theory of predication.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: Davidson defends the view that it is this way round. It is tempting to label them both as 'primitive'. Davidson distinguishes a 'theory' about truth from a 'definition'.
3. Truth / A. Truth Problems / 3. Value of Truth
Antirealism about truth prevents its use as an intersubjective standard [Davidson]
     Full Idea: Antirealism, with its limitations of truth to what can be ascertained, deprives truth of its role as an intersubjective standard.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: I like this, because it lifts truth out of individual minds. I take truth to be an ideal - a simple one with little content, which is thus fairly uncontroversial. Truth is the main general purpose of thinking.
3. Truth / A. Truth Problems / 8. Subjective Truth
'Epistemic' truth depends what rational creatures can verify [Davidson]
     Full Idea: The 'epistemic' view of truth asserts an essential tie to epistemology, and introduces a dependence of truth on what can somehow be verified by finite rational creatures.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: This view, which seems to be widely held, strikes me as an elementary confusion. I take truth to be fully successful belief. If you say belief can never be fully successful, then we can't know the truth - but that doesn't destroy the concept of truth.
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
All thought has the logical form of reality [Wittgenstein]
     Full Idea: Thought must have the logical form of reality if it is to be thought at all.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A V.1)
     A reaction: This links nicely the idea that true thoughts somehow share the structure of what they refer to, with the idea of logical form in logic. But maybe logical form is a fiction we offer in order to obtain a spurious map of reality.
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
There is nothing interesting or instructive for truths to correspond to [Davidson]
     Full Idea: The real objection to the correspondence theory of truth is that there is nothing interesting or instructive to which true sentences correspond. (C.I. Lewis challenged defenders to locate the fact or part of reality to which a truth corresponded).
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: Davidson defended a correspondence view in 'True to the Facts'. Davidson evidently also thinks the same objection applies to claims about truthmakers. If you say 'gold is shiny', the gold is very dispersed, but it is still there.
The Slingshot assumes substitutions give logical equivalence, and thus identical correspondence [Davidson]
     Full Idea: The Slingshot argument (of Frege, Church and Gödel) assumes that if two sentences are logically equivalent, they correspond to the same thing, and what a sentence corresponds to is not changed if a singular term is replaced by a coreferring term.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: This obviously won't work for 'Oedipus thinks he ought to marry Jocasta'. Sentences correspond, I presume, to what they are about, which is often a matter of emphasis or phrasing. Hence the Slingshot sounds like nonsense to me.
Two sentences can be rephrased by equivalent substitutions to correspond to the same thing [Davidson]
     Full Idea: Slingshot: 'Scott is the author of Waverley' and 'The number of counties in Utah is twenty-nine' can be rephrased by substitution so that they are both about the number twenty-nine, and are thus correspond to the same thing.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: [my paraphrase of Davidson's quote from Church 1956:24] These sentences clearly do not correspond to the same thing, so something has gone wrong with the idea that logically equivalent sentences have identical correspondents.
3. Truth / D. Coherence Truth / 1. Coherence Truth
Coherence truth says a consistent set of sentences is true - which ties truth to belief [Davidson]
     Full Idea: A pure coherence theory of truth says that all sentences in a consistent set of sentences are true. ...I class this with epistemic views, because it ties truth directly to what is believed.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: [He cites Neurath] I would have thought that coherence is rather more than mere consistency. Truths which have nothing whatever in common can be consistent with one another. [but see his p.43 n14]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
We can explain truth in terms of satisfaction - but also explain satisfaction in terms of truth [Davidson]
     Full Idea: Truth is easily defined in terms of satisfaction (as Tarski showed), but, alternatively, satisfaction can be taken to be whatever relation yields a correct account of truth.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: Davidson is assessing which is the prior 'primitive' concept, and he votes for truth. A perennial problem in philosophy, and very hard to find reasons for a preference. The axiomatic approach grows from taking truth as primitive. Axioms for satisfaction?
Satisfaction is a sort of reference, so maybe we can define truth in terms of reference? [Davidson]
     Full Idea: That the truth of sentences is defined by appeal to the semantic properties of words suggests that, if we could give an account of the semantic properties of words (essentially, of reference or satisfaction), we would understand the concept of truth.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: If you thought that words were prior to sentences, this might be the route to go. Davidson gives priority to sentences, and so prefers to work from the other end, which treats truth as primitive, and then defines reference and meaning.
Axioms spell out sentence satisfaction. With no free variables, all sequences satisfy the truths [Davidson]
     Full Idea: Axioms specify how each unstructured predicate is satisfied by a particular sequence. Then recursive axioms characterise complex sentences built from simpler ones. Closed sentences have no free variables, so true sentences are satisfied by all sequences.
     From: Donald Davidson (Truth and Predication [2005], 7)
     A reaction: I take 'all sequences' to mean all combinations of objects in the domain. Thus nothing in domain contradicts the satisfied sentences. Hence Tarski's truth is said to be 'true in a model', where the whole system vouches for the sentence.
3. Truth / F. Semantic Truth / 2. Semantic Truth
Many say that Tarski's definitions fail to connect truth to meaning [Davidson]
     Full Idea: It is complained that Tarski's definitions do not establish the connection between truth and meaning that many philosophers hold to be essential.
     From: Donald Davidson (Truth and Predication [2005], 1)
     A reaction: This, of course, was Davidson's big mission - to build on Tarski's theory a view of truth which dovetailed it with theories of meaning and reference.
Tarski does not tell us what his various truth predicates have in common [Davidson]
     Full Idea: There is no indication in Tarski's formal work of what it is that his various truth predicates have in common, and this is part of the content of the concept.
     From: Donald Davidson (Truth and Predication [2005], 1)
     A reaction: This seems like a good question to raise. If I list all the 'red' things, I can still ask what qualifies them to all appear on the same list.
Truth is the basic concept, because Convention-T is agreed to fix the truths of a language [Davidson]
     Full Idea: The key role of Convention-T in determining that truth, as characterised by the theory, has the same extension as the intuitive concept of truth makes it seem that it is truth rather than reference that is the basic primitive.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: The key strength of Tarski's account is that it specifies the extension of 'true' for a given language (as expressed in a richer meta-language).
To define a class of true sentences is to stipulate a possible language [Davidson]
     Full Idea: When we enquire whether a truth definition defines the class of true sentences in a particular language, we are thinking of the truth definition as stipulating a possible language.
     From: Donald Davidson (Truth and Predication [2005], 7)
     A reaction: Thus I might say "Nij wonk yang" is true if and only if snow is white, and make my first step towards a new language. An interesting way of looking at Tarski's project.
3. Truth / H. Deflationary Truth / 1. Redundant Truth
Truth is basic and clear, so don't try to replace it with something simpler [Davidson]
     Full Idea: Truth is one of the clearest and most basic concepts we have, so it is fruitless to dream of eliminating it in favor of something simpler or more fundamental.
     From: Donald Davidson (Truth and Predication [2005], 3)
     A reaction: For redundancy theorists, I suppose, truth would be eliminated in favour of 'assertion'. Replacing it with 'satisfaction' doesn't seem very illuminating. Davidson would say 'reference' is more tricky and elusive than truth.
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Tarski is not a disquotationalist, because you can assign truth to a sentence you can't quote [Davidson]
     Full Idea: It is clearly a mistake to call Tarski a disquotationalist. ...We say of a sentence not at hand (such as 'You gave the right answer to this question last night, but I can't remember what you said') that it is true or false.
     From: Donald Davidson (Truth and Predication [2005], 7)
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
In logic nothing is hidden [Wittgenstein]
     Full Idea: In logic nothing is hidden.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.3)
     A reaction: If so, then the essence of logic must be there for all to see. The rules of natural deduction are a good shot at showing this.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is our preconditions for assessing empirical evidence [Kitcher]
     Full Idea: In my terminology, classical logic (or at least, its most central tenets) consists of propositional preconditions for our assessing empirical evidence in the way we do.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §VII)
     A reaction: I like an even stronger version of this - that classical logic arises out of our experiences of things, and so we are just assessing empirical evidence in terms of other (generalised) empirical evidence. Logic results from induction. Very unfashionable.
I believe classical logic because I was taught it and use it, but it could be undermined [Kitcher]
     Full Idea: I believe the laws of classical logic, in part because I was taught them, and in part because I think I see how those laws are used in assessing evidence. But my belief could easily be undermined by experience.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §VII)
     A reaction: Quine has one genuine follower! The trouble is his first sentence would fit witch-doctoring just as well. Kitcher went to Cambridge; I hope he doesn't just believe things because he was taught them, or because he 'sees how they are used'!
5. Theory of Logic / C. Ontology of Logic / 4. Logic by Convention
Laws of logic are like laws of chess - if you change them, it's just a different game [Wittgenstein]
     Full Idea: I might as well question the laws of logic as the laws of chess. If I change the rules it is a different game and there is an end of it.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A XI.3)
     A reaction: No, that isn't the end of it, because there are meta-criteria for preferring one game to another. Why don't we just give up classical logic? It would be such fun to have a wild wacky logic. We can start with 'tonk'.
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Contradiction is between two rules, not between rule and reality [Wittgenstein]
     Full Idea: Contradiction is between one rule and another, not between rule and reality.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII)
     A reaction: If I say 'he is sitting' and 'he is standing', it seems to be reality which produces the contradiction. What 'rule' could possibly do it? The rule which says sitting and standing are incompatible? But what makes that so?
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
We may correctly use 'not' without making the rule explicit [Wittgenstein]
     Full Idea: Correct use does not imply the ability to make the rules explicit. Understanding 'not' is like understanding a move in chess.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.1)
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and
Saying 'and' has meaning is just saying it works in a sentence [Wittgenstein]
     Full Idea: When we say that the word 'and' has meaning what we mean is that it works in a sentence and is not just a flourish.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII.2)
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
A person's name doesn't mean their body; bodies don't sit down, and their existence can be denied [Wittgenstein]
     Full Idea: The meaning of the words 'Professor Moore' is not a certain human body, because we do not say that the meaning sits on the sofa, and the words occur in the proposition 'Professor Moore does not exist'.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B Easter)
     A reaction: Brilliant. Love it. Kripke ending up denying the existence of 'meanings'.
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
'Satisfaction' is a generalised form of reference [Davidson]
     Full Idea: We can think of 'satisfaction' as a generalised form of reference.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: Just the sort of simple point we novices need from the great minds, to help us see what is going on. One day someone is going to explain Tarski's account of truth in plain English, but probably not in my lifetime.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
We don't get 'nearer' to something by adding decimals to 1.1412... (root-2) [Wittgenstein]
     Full Idea: We say we get nearer to root-2 by adding further figures after the decimal point: 1.1412.... This suggests there is something we can get nearer to, but the analogy is a false one.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], Notes)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Infinity is not a number, so doesn't say how many; it is the property of a law [Wittgenstein]
     Full Idea: 'Infinite' is not an answer to the question 'How many?', since the infinite is not a number. ...Infinity is the property of a law, not of an extension.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A VII.2)
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
There are no positive or negative facts; these are just the forms of propositions [Wittgenstein]
     Full Idea: There are no positive or negative facts. 'Positive' and 'negative' refer to the form of propositions, and not to the facts which verify or falsify them.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII)
     A reaction: Personally I think if we are going to allow the world to be full of 'facts', then there are negative, conjunctive, disjunctive and hypothetical facts.
8. Modes of Existence / B. Properties / 11. Properties as Sets
Treating predicates as sets drops the predicate for a new predicate 'is a member of', which is no help [Davidson]
     Full Idea: 'Theaetetus is a member of the set of seated objects' doesn't mention the predicate 'sits', but has a new predicate 'is a member of', with no given semantic role. We are back with Plato's problem with the predicate 'instantiates'.
     From: Donald Davidson (Truth and Predication [2005], 7)
     A reaction: Plato's problem is the 'third man' problem - a regress in the explanation. In other words, if we are trying to explain predication, treating predicates as sets gets us nowhere. Just as I always thought. But you have to want explanations.
8. Modes of Existence / D. Universals / 5. Universals as Concepts
Using 'green' is a commitment to future usage of 'green' [Wittgenstein]
     Full Idea: If I say this is green, I must say that other things are green too. I am committed to a future usage.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VI.2)
     A reaction: This seems to suggest that the eternal verity of a universal concept is just a convention of stability in a language.
10. Modality / B. Possibility / 6. Probability
Probability can be constrained by axioms, but that leaves open its truth nature [Davidson]
     Full Idea: Kolmogorov's axiomatisation of probability puts clear constraints on the concept of probability, but leaves open whether probability is further characterised as relative frequency, degree of belief, or something else.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: Davidson cites this to show the limitations of axiomatic approaches to any topic (e.g. sets, truth, arithmetic). The item in question must be treated as a 'primitive'. This always has the feeling of second-best.
10. Modality / C. Sources of Modality / 3. Necessity by Convention
For each necessity in the world there is an arbitrary rule of language [Wittgenstein]
     Full Idea: To a necessity in the world there corresponds an arbitrary rule in language.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIV.2)
     A reaction: This seems to be hardcore logical positivism, making all necessities arbitrary. Compare Quine on the number of planets.
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
Many necessities are inexpressible, and unknowable a priori [Kitcher]
     Full Idea: There are plenty of necessary truths that we are unable to express, let alone know a priori.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §II)
     A reaction: This certainly seems to put paid to any simplistic idea that the a priori and the necessary are totally coextensive. We might, I suppose, claim that all necessities are a priori for the Archangel Gabriel (or even a very bright cherub). Cf. Idea 12429.
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
Knowing our own existence is a priori, but not necessary [Kitcher]
     Full Idea: What is known a priori may not be necessary, if we know a priori that we ourselves exist and are actual.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §II)
     A reaction: Compare Idea 12428, which challenges the inverse of this relationship. This one looks equally convincing, and Kripke adds other examples of contingent a priori truths, such as those referring to the metre rule in Paris.
11. Knowledge Aims / A. Knowledge / 2. Understanding
Understanding is translation, into action or into other symbols [Wittgenstein]
     Full Idea: Understanding is really translation, whether into other symbols or into action.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.5)
     A reaction: The second part of this sounds like pure pragmatism. To do is to understand? I doubt it. Do animals understand anything?
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
We live in sense-data, but talk about physical objects [Wittgenstein]
     Full Idea: The world we live in is the world of sense-data, but the world we talk about is the world of physical objects.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], p.82), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Verif'
     A reaction: I really like that one. Even animals, I surmise, think of objects quite differently from the way they immediately experience them.
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Part of what we mean by stating the facts is the way we tend to experience them [Wittgenstein]
     Full Idea: There is no need of a theory to reconcile what we know about sense data and what we believe about physical objects, because part of what we mean by saying that a penny is round is that we see it as elliptical in such and such conditions.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C III)
     A reaction: This is an interesting and cunning move to bridge the gap between our representations and reallity. We may surmise how a thing really is, but then be surprised by the sense-data we get from it.
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
If you remember wrongly, then there must be some other criterion than your remembering [Wittgenstein]
     Full Idea: If you remember wrongly, then there must be some other criterion than your remembering. If you admit another test, then your memory itself is not the test.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C VII)
     A reaction: If I fear that I am remembering some private solitary event wrongly, there is no other criterion to turn to, so I'm stuck. Sometimes dubious memories are all we have.
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
Explanation and understanding are the same [Wittgenstein]
     Full Idea: For us explanation and understanding are the same, understanding being the correlate of explanation.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XI.2)
     A reaction: I'm not convinced that they are 'the same', but they are almost interdependent ideas. Strevens has a nice paper on this.
Explanation gives understanding by revealing the full multiplicity of the thing [Wittgenstein]
     Full Idea: An explanation gives understanding, ...but it cannot teach you understanding, it cannot create understanding. It makes further distinctions i.e. it increases multiplicity. When multiplicity is complete, then there is no further misunderstanding.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B X.3)
     A reaction: The thought seems to resemble Aristotle's idea of definition as gradual division of the subject. To understand is the dismantle the parts and lay them out before us. Wittgenstein was very interested in explanation at this time.
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
A machine strikes us as being a rule of movement [Wittgenstein]
     Full Idea: We are accustomed to look on a machine as the expression of a rule of movement.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VII.2)
     A reaction: What a beautiful definition of a machine! I like this because it connects the two halves of my view of the 'essence' of a thing, as derived from Aristotle, as both a causal mechanism and an underlying principle. Cf Turing machines.
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
If an explanation is good, the symbol is used properly in the future [Wittgenstein]
     Full Idea: The criterion of an explanation is whether the symbol explained is used properly in the future.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B II.4)
     A reaction: This appears to be a pragmatic criterion for the best explanation. It presumably rests on his doctrine that meaning is use, so good explanation is understanding meanings.
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Predicates are a source of generality in sentences [Davidson]
     Full Idea: Predicates introduce generality into sentences.
     From: Donald Davidson (Truth and Predication [2005], 7)
     A reaction: Not sure about this. Most words introduce generality. 'From' is a very general word about direction. 'Dogs bark' is as generally about dogs as it is generally about barking.
18. Thought / A. Modes of Thought / 1. Thought
Thought is an activity which we perform by the expression of it [Wittgenstein]
     Full Idea: Thought is an activity which we perform by the expression of it, and lasts as long as the expression.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII)
     A reaction: I take this to be an outmoded view of thought, which modern cognitive science has undermined, by showing how little of our thinking is actually conscious.
19. Language / A. Nature of Meaning / 2. Meaning as Mental
If we reject corresponding 'facts', we should also give up the linked idea of 'representations' [Davidson]
     Full Idea: If we give up facts that make entities true, we ought to give up representations at the same time, for the legitimacy of each depends on the legitimacy of the other.
     From: Donald Davidson (Truth and Predication [2005], 2)
     A reaction: Not sure about this, because I'm not sure I know what he means by 'representations'. Surely every sentence is 'about' something? Is that just the references within the sentence, but not the sentence as a whole?
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
A proposition draws a line around the facts which agree with it [Wittgenstein]
     Full Idea: A proposition gives reality a degree of freedom; it draws a line round the facts which agree with it, and distinguishes them from those which do not.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIII.2)
     A reaction: This seems to be the idea of meaning as the range of truth conditions. Propositions as sets of possible worlds extends this into possible facts which agree with the proposition. Most facts neither agree nor disagree with some proposition.
You only understand an order if you know what it is to obey it [Davidson]
     Full Idea: We understand an imperative if and only if we know under what conditions what it orders or commands is obeyed.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: How could this be wrong? 'Do you understand the order?' 'Yes sir!' 'Well do it then!' 'Do what sir?'
Utterances have the truth conditions intended by the speaker [Davidson]
     Full Idea: An utterance has certain truth conditions only if the speaker intends it to be interpreted as having those truth conditions.
     From: Donald Davidson (Truth and Predication [2005], 3)
     A reaction: This seems to be a concession to the rather sensible things that Grice said about meaning. What about malapropisms? Surely there the speaker does not understand the truth conditions of her own utterance? Truth conditions are in the head?
19. Language / A. Nature of Meaning / 5. Meaning as Verification
The meaning of a proposition is the mode of its verification [Wittgenstein]
     Full Idea: The meaning of a proposition is the mode of its verification (and two propositions cannot have the same verification).
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C I)
     A reaction: Does this mean that if two sentences have the same mode of verification, then they must be expressing the same proposition? I guess so.
19. Language / A. Nature of Meaning / 6. Meaning as Use
Meaning involves use, but a sentence has many uses, while meaning stays fixed [Davidson]
     Full Idea: Meaning depends on use, but it is not easy to say how, for uses to which we may put the utterance of a sentence are endless while its meaning remains fixed.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: Quite so. The password is 'Swordfish' (or 'Sweet marjoram', if you prefer).
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Words function only in propositions, like levers in a machine [Wittgenstein]
     Full Idea: Words function only in propositions, like the levers in a machine.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4)
     A reaction: Hm. Consider the word 'tree'. Did you manage to do it? Was it just a noise?
We recognise sentences at once as linguistic units; we then figure out their parts [Davidson]
     Full Idea: Our interest in the parts of sentences is derivative; we recognise at once that sentences are effective linguistic units, while we must figure out or decide what constitutes the meaningful words and particles.
     From: Donald Davidson (Truth and Predication [2005], Intro)
     A reaction: It depends on whether linguistic priority goes to complete thoughts that require expression, or to naming and ostensive definition to relate to elements of the environment. I find it hard to have a strong view on this one. Just So stories?
19. Language / C. Assigning Meanings / 3. Predicates
Modern predicates have 'places', and are sentences with singular terms deleted from the places [Davidson]
     Full Idea: The notion of 'places' in a predicate is the key to the modern concept of a predicate. Any expression obtained from a sentence by deleting one or more singular terms from the sentence counts as a predicate.
     From: Donald Davidson (Truth and Predication [2005], 4)
The concept of truth can explain predication [Davidson]
     Full Idea: My strategy is to show how our grasp of the concept of truth can explain predication.
     From: Donald Davidson (Truth and Predication [2005], 7)
     A reaction: His account of the concept of truth centres on Tarski's theory, but he clearly thinks more is needed than the bare bones offered by Tarski. The point, I think, is that predication is what makes a sentence 'truth-apt'.
19. Language / C. Assigning Meanings / 4. Compositionality
If you assign semantics to sentence parts, the sentence fails to compose a whole [Davidson]
     Full Idea: The puzzle is that once plausible assignments of semantic roles have been made to parts of sentences, the parts do not seem to compose a united whole.
     From: Donald Davidson (Truth and Predication [2005], Intro)
     A reaction: It's not clear to me that a sentence does compose a 'whole', given that you can often add or remove bits from sentences, sometimes without changing the meaning. We often, in speech, assemble sentences before we have thought of their full meaning.
19. Language / C. Assigning Meanings / 6. Truth-Conditions Semantics
Top-down semantic analysis must begin with truth, as it is obvious, and explains linguistic usage [Davidson]
     Full Idea: Truth is the essential semantic concept with which to begin a top-down analysis of sentences, since truth, or lack of it, is the most obvious semantic property of sentences, and provides the clearest explanation of judging and conveying information.
     From: Donald Davidson (Truth and Predication [2005], Intro)
     A reaction: [a bit compressed] Presumably this goes with giving sentences semantic priority. The alternative approach is compositional, and is likely to give reference of terms priority over truth of the sentence. But accurate reference is a sort of truth.
19. Language / D. Propositions / 1. Propositions
A proposition is any expression which can be significantly negated [Wittgenstein]
     Full Idea: Any affirmation can be negated: if it has sense to say p it also has sense to say ¬p. ...A proposition therefore is any expression which can be significantly negated.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.2)
     A reaction: I'm not sure about 'therefore'. I'm thinking you would have to already grasp the proposition in order to apply his negation test.
'Humanity belongs to Socrates' is about humanity, so it's a different proposition from 'Socrates is human' [Davidson]
     Full Idea: The sentence 'Humanity belongs to Socrates' is about the concept of humanity, unlike the "equivalent" 'Socrates is human', so they express different propositions.
     From: Donald Davidson (Truth and Predication [2005], 5)
     A reaction: [compressed] I like this a lot, because it shows why we should focus on propositions rather than on sentences, or even utterances. And asking what the sentence is 'about' focuses us on the underlying proposition or thought.
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
The principle of charity says an interpreter must assume the logical constants [Davidson]
     Full Idea: The principle of charity says that it is unavoidable that the pattern of sentences to which a speaker assents reflects the semantics of the logical constants.
     From: Donald Davidson (Truth and Predication [2005], 3)
     A reaction: That is not all the principle says, of course. Davidson seems to assume classical logic here, with a bivalent semantics. I wonder if all speakers use 'false' in the normal way, as well as 'true'? Do all languages even contain 'true'?
19. Language / F. Communication / 6. Interpreting Language / d. Metaphor
We indicate use of a metaphor by its obvious falseness, or trivial truth [Davidson]
     Full Idea: The sentences that contain metaphors are typically obviously false or trivially true, because these are typically indications that something is intended as a metaphor.
     From: Donald Davidson (Truth and Predication [2005], 6)
     A reaction: A nice point which sounds correct. Metaphors are famous being false, but the 'obvious' falseness signals the metaphor. If a metaphor is only obscurely false, that makes it difficult to read.
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
Laws of nature are an aspect of the phenomena, and are just our mode of description [Wittgenstein]
     Full Idea: The laws of nature are not outside phenomena. They are part of language and of our way of describing things; you cannot discuss them apart from their physical manifestation.
     From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V C)
     A reaction: I suppose this amounts to a Humean regularity theory - that the descriptions pick out patterns in the manifestations. I like the initial claim that they are not external to phenomena.