20 ideas
| 15647 | 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. |
| 15649 | 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. |
| 15655 | 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] |
| 15654 | 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. |
| 15648 | 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. |
| 15650 | 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) |
| 15656 | 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'. |
| 15657 | 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) |
| 15652 | 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. |
| 15651 | 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. |
| 20298 | The traditional a priori is justified without experience; post-Quine it became unrevisable by experience [Rey] |
| Full Idea: Where Kant and others had traditionally assumed that the a priori concerned beliefs 'justifiable independently of experience', Quine and others of the time came to regard it as beliefs 'unrevisable in the light of experience'. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 3.7) | |
| A reaction: That throws a rather striking light on Quine's project. Of course, if the a priori is also necessary, then it has to be unrevisable. But is a bachelor necessarily an unmarried man? It is not necessary that 'bachelor' has a fixed meaning. |
| 20300 | Externalist synonymy is there being a correct link to the same external phenomena [Rey] |
| Full Idea: Externalists are typically committed to counting expressions as 'synonymous' if they happen to be linked in the right way to the same external phenomena, even if a thinker couldn't realise that they are by reflection alone. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 4.2) | |
| A reaction: [He cites Fodor] Externalists always try to link to concrete things in the world, but most of our talk is full of generalities, abstractions and fiction which don't link directly to anything. |
| 20294 | 'Married' does not 'contain' its symmetry, nor 'bigger than' its transitivity [Rey] |
| Full Idea: If Bob is married to Sue, then Sue is married to Bob. If x bigger than y, and y bigger than z, x is bigger than z. The symmetry of 'marriage' or transitivity of 'bigger than' are not obviously 'contained in' the corresponding thoughts. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 1.2) | |
| A reaction: [Also 'if something is red, then it is coloured'] This is a Fregean criticism of Kant. It is not so much that Kant was wrong, as that the concept of analyticity is seen to have a much wider application than Kant realised. Especially in mathematics. |
| 20293 | Analytic judgements can't be explained by contradiction, since that is what is assumed [Rey] |
| Full Idea: Rejecting 'a married bachelor' as contradictory would seem to have no justification other than the claim that 'All bachelors are unmarried is analytic, and so cannot serve to justify or explain that claim. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 1.2) | |
| A reaction: Rey is discussing Frege's objection to Kant (who tried to prove the necessity of analytic judgements, on the basis of the denial being a contradiction). |
| 20297 | Analytic statements are undeniable (because of meaning), rather than unrevisable [Rey] |
| Full Idea: What's peculiar about the analytic is that denying it seem unintelligible. Far from unrevisability explaining analyticity, it seems to be analyticitiy that explains unrevisability; we only balk at denying unmarried bachelors because that's what it means! | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 3.7) | |
| A reaction: This is a criticism of Quine, who attacked analyticity when it is understood as unrevisability. Obviously we could revise the concept of 'bachelor', if our marriage customs changed a lot. Rey seems right here. |
| 20301 | The meaning properties of a term are those which explain how the term is typically used [Rey] |
| Full Idea: It may be that the meaning properties of a term are the ones that play a basic explanatory role with regard to the use of the term generally, the ones in virtue ultimately of which a term is used with that meaning. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 4.3) | |
| A reaction: [He cites Devitt 1996, 2002, and Horwich 1998, 2005) I spring to philosophical life whenever I see the word 'explanatory', because that is the point of the whole game. They are pointing to the essence of the concept (which is explanatory, say I). |
| 20302 | An intrinsic language faculty may fix what is meaningful (as well as grammatical) [Rey] |
| Full Idea: The existence of a separate language faculty may be an odd but psychologically real fact about us, and it may thereby supply a real basis for commitments about not only what is or is not grammatical, but about what is a matter of natural language meaning. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 4.4) | |
| A reaction: This is the Chomskyan view of analytic sentences. An example from Chomsky (1977:142) is the semantic relationships of persuade, intend and believe. It's hard to see how the secret faculty on its own could do the job. Consensus is needed. |
| 20303 | Research throws doubts on the claimed intuitions which support analyticity [Rey] |
| Full Idea: The movement of 'experimental philosophy' has pointed to evidence of considerable malleability of subject's 'intuitions' with regard to the standard kinds of thought experiments on which defenses of analytic claims typically rely. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 4.4) | |
| A reaction: See Cappelen's interesting attack on the idea that philosophy relies on intuitions, and hence his attack on experimental philosophy. Our consensus on ordinary English usage hardly qualifies as somewhat vague 'intuitions'. |
| 20299 | If we claim direct insight to what is analytic, how do we know it is not sub-consciously empirical? [Rey] |
| Full Idea: How in the end are we going to distinguish claims or the analytic as 'rational insight', 'primitive compulsion', inferential practice or folk belief from merely some deeply held empirical conviction, indeed, from mere dogma. | |
| From: Georges Rey (The Analytic/Synthetic Distinction [2013], 4.1) | |
| A reaction: This is Rey's summary of the persisting Quinean challenge to analytic truths, in the face of a set of replies, summarised by the various phrases here. So do we reject a dogma of empiricism, by asserting dogmatic empiricism? |
| 8409 | Probabilistic causal concepts are widely used in everyday life and in science [Salmon] |
| Full Idea: Probabilistic causal concepts are used in innumerable contexts of everyday life and science. ...In causes of cancer, road accidents, or food poisoning, for example. | |
| From: Wesley Salmon (Probabilistic Causality [1980], p.137) | |
| A reaction: [Second half compresses his examples] This strikes me as rather a weak point. No one ever thought that a particular road accident was actually caused by the high probability of it at a particular location. Causes are in the mechanisms. |