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All the ideas for 'Axiomatic Theories of Truth (2005 ver)', 'Some Main Problems of Philosophy' and 'Truth and Predication'

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43 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / c. Philosophy as generalisation
The main aim of philosophy is to describe the whole Universe. [Moore,GE]
     Full Idea: It seems to me that the most important and interesting thing which philosophers have tried to do ...is to give a general description of the whole of the Universe.
     From: G.E. Moore (Some Main Problems of Philosophy [1911], Ch. 1)
     A reaction: He adds that they aim to show what is in it, and what might be in it, and how the two relate. This sort of big view is the one I favour. I think the hallmark of philosophical thought is a high level of generality. He next proceeds to defend common sense.
3. Truth / A. Truth Problems / 2. Defining Truth
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'.
Truth definitions don't produce a good theory, because they go beyond your current language [Halbach]
     Full Idea: It is far from clear that a definition of truth can lead to a philosophically satisfactory theory of truth. Tarski's theorem on the undefinability of the truth predicate needs resources beyond those of the language for which it is being defined.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: The idea is that you need a 'metalanguage' for the definition. If I say 'p' is a true sentence in language 'L', I am not making that observation from within language L. The dream is a theory confined to the object language.
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 / 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 / 1. Tarski's Truth / c. Meta-language for truth
In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach]
     Full Idea: In semantic theories of truth (Tarski or Kripke), a truth predicate is defined for an object-language. This definition is carried out in a metalanguage, which is typically taken to include set theory or another strong theory or expressive language.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: Presumably the metalanguage includes set theory because that connects it with mathematics, and enables it to be formally rigorous. Tarski showed, in his undefinability theorem, that the meta-language must have increased resources.
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 / G. Axiomatic Truth / 1. Axiomatic Truth
Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach]
     Full Idea: If truth is not explanatory, truth axioms should not allow proof of new theorems not involving the truth predicate. It is hence said that axiomatic truth should be 'conservative' - not implying further sentences beyond what the axioms can prove.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: [compressed]
If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach]
     Full Idea: If truth can be explicitly defined, it can be eliminated, whereas an axiomatized notion of truth may bring all kinds of commitments.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: The general principle that anything which can be defined can be eliminated (in an abstract theory, presumably, not in nature!) raises interesting questions about how many true theories there are which are all equivalent to one another.
Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach]
     Full Idea: Axiomatic theories of truth can be presented within very weak logical frameworks which require very few resources, and avoid the need for a strong metalanguage and metatheory.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach]
     Full Idea: The axiomatic approach does not presuppose that truth can be defined. Instead, a formal language is expanded by a new primitive predicate of truth, and axioms for that predicate are then laid down.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: Idea 15647 explains why Halbach thinks the definition route is no good.
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
Deflationists say truth merely serves to express infinite conjunctions [Halbach]
     Full Idea: According to many deflationists, truth serves merely the purpose of expressing infinite conjunctions.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: That is, it asserts sentences that are too numerous to express individually. It also seems, on a deflationist view, to serve for anaphoric reference to sentences, such as 'what she just said is true'.
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)
4. Formal Logic / F. Set Theory ST / 1. Set Theory
To prove the consistency of set theory, we must go beyond set theory [Halbach]
     Full Idea: The consistency of set theory cannot be established without assumptions transcending set theory.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 2.1)
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach]
     Full Idea: The reduction of 2nd-order theories (of properties or sets) to axiomatic theories of truth may be conceived as a form of reductive nominalism, replacing existence assumptions (for comprehension axioms) by ontologically innocent truth assumptions.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1)
     A reaction: I like this very much, as weeding properties out of logic (without weeding them out of the world). So-called properties in logic are too abundant, so there is a misfit with their role in science.
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach]
     Full Idea: Quantification over (certain) properties can be mimicked in a language with a truth predicate by quantifying over formulas. Instead of saying that Tom has the property of being a poor philosopher, we can say 'x is a poor philosopher' is true of Tom.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1)
     A reaction: I love this, and think it is very important. He talks of 'mimicking' properties, but I see it as philosophers mistakenly attributing properties, when actually what they were doing is asserting truths involving certain predicates.
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.
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.
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.
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.
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
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 / 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
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
'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.