29 ideas
| 6334 | The function of the truth predicate? Understanding 'true'? Meaning of 'true'? The concept of truth? A theory of truth? [Horwich] |
| Full Idea: We must distinguish the function of the truth predicate, what it is to understand 'true', the meaning of 'true', grasping the concept of truth, and a theory of truth itself. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.2.8) | |
| A reaction: It makes you feel tired to think about it. Presumably every other philosophical analysis has to do this many jobs. Clearly Horwich wants to propose one account which will do all five jobs. Personally I don't believe these five are really distinct. |
| 6342 | Some correspondence theories concern facts; others are built up through reference and satisfaction [Horwich] |
| Full Idea: One correspondence theory (e.g. early Wittgenstein) concerns representations and facts; alternatively (Tarski, Davidson) the category of fact is eschewed, and the truth of sentences or propositions is built out of relations of reference and satisfaction. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.7.35) | |
| A reaction: A helpful distinction. Clearly the notion of a 'fact' is an elusive one ("how many facts are there in this room?"), so it seems quite promising to say that the parts of the sentence correspond, rather than the whole thing. |
| 6332 | The common-sense theory of correspondence has never been worked out satisfactorily [Horwich] |
| Full Idea: The common-sense notion that truth is a kind of 'correspondence with the facts' has never been worked out to anyone's satisfaction. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.1) | |
| A reaction: I've put this in to criticise it. Philosophy can't work by rejecting theories which can't be 'worked out', and accepting theories (like Tarski's) because they can be 'worked out'. All our theories will end up minimal, and defiant of common sense. |
| 6335 | The redundancy theory cannot explain inferences from 'what x said is true' and 'x said p', to p [Horwich] |
| Full Idea: The redundancy theory is unable to account for the inference from "Oscar's claim is true" and "Oscar's claim is that snow is white" to "the proposition 'that snow is white' is true", and hence to "snow is white". | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.2.9) | |
| A reaction: Earlier objections appealed to the fact that the word 'true' seemed to have a use in ordinary speech, but this seems a much stronger one. In general, showing the role of a term in making inferences pins it down better than ordinary speech does. |
| 6344 | Truth is a useful concept for unarticulated propositions and generalisations about them [Horwich] |
| Full Idea: All uses of the truth predicate are explained by the hypothesis that its entire raison d'être is to help us say things about unarticulated propositions, and in particular to express generalisations about them. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Concl) | |
| A reaction: This certain is a very deflationary notion of truth. Articulated propositions are considered to stand on their own two feet, without need of 'is true'. He makes truth sound like a language game, though. Personally I prefer to mention reality. |
| 6336 | No deflationary conception of truth does justice to the fact that we aim for truth [Horwich] |
| Full Idea: It has been suggested that no deflationary conception of truth could do justice to the fact that we aim for the truth. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.2.11) | |
| A reaction: (He mentions Dummett and Wright). People don't only aim for it - they become very idealistic about it, and sometimes die for it. Personally I think that any study of truth should use as its example police investigations, not philosophical analysis. |
| 23299 | Horwich's deflationary view is novel, because it relies on propositions rather than sentences [Horwich, by Davidson] |
| Full Idea: Horwich's brave and striking move is to make the primary bearers of truth propositions - not exactly a new idea in itself, but new in the context of a serious attempt to defend deflationism. | |
| From: report of Paul Horwich (Truth (2nd edn) [1990]) by Donald Davidson - The Folly of Trying to Define Truth p.30 | |
| A reaction: Davidson rejects propositions because they can't be individuated, but I totally accept propositions. I'm puzzled why this would produce a deflationist theory, since I think it points to a much more robust view. |
| 6337 | The deflationary picture says believing a theory true is a trivial step after believing the theory [Horwich] |
| Full Idea: According to the deflationary picture, believing that a theory is true is a trivial step beyond believing the theory. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.2.17) | |
| A reaction: What has gone wrong with this picture is that you cannot (it seems to me) give a decent account of belief without mentioning truth. To believe a proposition is to hold it true. Hume's emotional account (Idea 2208) makes belief bewildering. |
| 10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
| Full Idea: The main objection to the axiom of choice was that it had to be given by some law or definition, but since sets are arbitrary this seems irrelevant. Formalists consider it meaningless, but set-theorists consider it as true, and practically obvious. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) |
| 10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
| Full Idea: One can distinguish at least two quite different senses of logic: as an instrument of demonstration, and perhaps as an instrument for the characterization of structures. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: This is trying to capture the proof-theory and semantic aspects, but merely 'characterizing' something sounds like a rather feeble aspiration for the semantic side of things. Isn't it to do with truth, rather than just rule-following? |
| 10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
| Full Idea: Elementary logic cannot characterize the usual mathematical structures, but seems to be distinguished by its completeness. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
| Full Idea: The expressive power of second-order logic is too great to admit a proof procedure, but is adequate to express set-theoretical statements, and open questions such as the continuum hypothesis or the existence of big cardinals are easily stated. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 6339 | Logical form is the aspects of meaning that determine logical entailments [Horwich] |
| Full Idea: The logical forms of the sentences in a language are those aspects of their meanings that determine the relations of deductive entailment holding amongst them. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.6.30) | |
| A reaction: A helpful definition. Not all sentences, therefore, need to have a 'logical form'. Is the logical form the same as the underlying proposition. The two must converge, given that propositions lack the ambiguity that is often found in sentences. |
| 10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
| Full Idea: In sentential logic there is a simple proof that all truth functions, of any number of arguments, are definable from (say) 'not' and 'and'. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §0) | |
| A reaction: The point of 'say' is that it can be got down to two connectives, and these are just the usual preferred pair. |
| 10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
| Full Idea: The symbols ∀ and ∃ may, to start with, be regarded as extrapolations of the truth functional connectives ∧ ('and') and ∨ ('or') to infinite domains. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §5) |
| 10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
| Full Idea: One might add to one's logic an 'uncountable quantifier', or a 'Chang quantifier', or a 'two-argument quantifier', or 'Shelah's quantifier', or 'branching quantifiers'. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) | |
| A reaction: [compressed - just listed for reference, if you collect quantifiers, like collecting butterflies] |
| 10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
| Full Idea: Skolem deduced from the Löwenheim-Skolem theorem that 'the absolutist conceptions of Cantor's theory' are 'illusory'. I think it is clear that this conclusion would not follow even if elementary logic were in some sense the true logic, as Skolem assumed. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §7) | |
| A reaction: [Tharp cites Skolem 1962 p.47] Kit Fine refers to accepters of this scepticism about the arithmetic of infinities as 'Skolemites'. |
| 10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
| Full Idea: The Löwenheim-Skolem property seems to be undesirable, in that it states a limitation concerning the distinctions the logic is capable of making, such as saying there are uncountably many reals ('Skolem's Paradox'). | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
| Full Idea: Soundness would seem to be an essential requirement of a proof procedure, since there is little point in proving formulas which may turn out to be false under some interpretation. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10763 | Completeness and compactness together give axiomatizability [Tharp] |
| Full Idea: Putting completeness and compactness together, one has axiomatizability. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §1) |
| 10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
| Full Idea: In general, if completeness fails there is no algorithm to list the valid formulas. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: I.e. the theory is not effectively enumerable. |
| 10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
| Full Idea: It is strange that compactness is often ignored in discussions of philosophy of logic, since the most important theories have infinitely many axioms. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: An example of infinite axioms is the induction schema in first-order Peano Arithmetic. |
| 10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
| Full Idea: The compactness condition seems to state some weakness of the logic (as if it were futile to add infinitely many hypotheses). To look at it another way, formalizations of (say) arithmetic will admit of non-standard models. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
| Full Idea: A complete logic has an effective enumeration of the valid formulas. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
| Full Idea: Despite completeness, the mere existence of an effective enumeration of the valid formulas will not, by itself, provide knowledge. For example, one might be able to prove that there is an effective enumeration, without being able to specify one. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: The point is that completeness is supposed to ensure knowledge (of what is valid but unprovable), and completeness entails effective enumerability, but more than the latter is needed to do the key job. |
| 6338 | We could know the truth-conditions of a foreign sentence without knowing its meaning [Horwich] |
| Full Idea: Someone who does not understand German and is told 'Schnee ist weiss' is true if frozen H2O is white, does not understand the German sentence, even though he knows the truth-conditions. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.5.22 n1) | |
| A reaction: This sounds like a powerful objection to Davidson's well-known claim that meaning is truth-conditions. Horwich likes the idea that meaning is use, but I think a similar objection arises - you can use a sentence well without knowing its meaning. |
| 6340 | There are Fregean de dicto propositions, and Russellian de re propositions, or a mixture [Horwich] |
| Full Idea: There are pure, Fregean, abstract, de dicto propositions, in which a compositional structure is filled only with senses; there are pure, Russellian, concrete, de re propositions, which are filled with referents; and there are mixed propositions. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.6.31) | |
| A reaction: Once Frege has distinguished sense from reference, this distinction of propositions is likely to follow. The current debate over the internalist and externalist accounts of concepts seems to continue the debate. A mixed strategy sounds good. |
| 6341 | Right translation is a mapping of languages which preserves basic patterns of usage [Horwich] |
| Full Idea: The right translation between words of two languages is the mapping that preserves basic patterns of usage - where usage is characterised non-semantically, in terms of circumstances of application, assertibility conditions and inferential role. | |
| From: Paul Horwich (Truth (2nd edn) [1990], Ch.6.32) | |
| A reaction: It still strikes me that if you ask why a piece of language is used in a certain way, you find yourself facing something deeper about meaning than mere usage. Horwich cites Wittgenstein and Quine in his support. Could a machine pass his test? |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |