26 ideas
| 10633 | 'Some critics admire only one another' cannot be paraphrased in singular first-order [Linnebo] |
| Full Idea: The Geach-Kaplan sentence 'Some critics admire only one another' provably has no singular first-order paraphrase using only its predicates. | |
| From: Øystein Linnebo (Plural Quantification [2008], 1) | |
| A reaction: There seems to be a choice of either going second-order (picking out a property), or going plural (collectively quantifying), or maybe both. |
| 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. |
| 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) |
| 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. |
| 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) |
| 10638 | A pure logic is wholly general, purely formal, and directly known [Linnebo] |
| Full Idea: The defining features of a pure logic are its absolute generality (the objects of discourse are irrelevant), and its formality (logical truths depend on form, not matter), and its cognitive primacy (no extra-logical understanding is needed to grasp it). | |
| From: Øystein Linnebo (Plural Quantification [2008], 3) | |
| A reaction: [compressed] This strikes me as very important. The above description seems to contain no ontological commitment at all, either to the existence of something, or to two things, or to numbers, or to a property. Pure logic seems to be 'if-thenism'. |
| 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. |
| 10640 | Instead of complex objects like tables, plurally quantify over mereological atoms tablewise [Linnebo] |
| Full Idea: Plural quantification can be used to eliminate the commitment of science and common sense to complex objects. We can use plural quantification over mereological atoms arranged tablewise or chairwise. | |
| From: Øystein Linnebo (Plural Quantification [2008], 4.5) | |
| A reaction: [He cites Hossack and van Ingwagen] |
| 10636 | Plural plurals are unnatural and need a first-level ontology [Linnebo] |
| Full Idea: Higher-order plural quantification (plural plurals) is often rejected because plural quantification is supposedly ontological innocent, with no plural things to be plural, and because it is not found in ordinary English. | |
| From: Øystein Linnebo (Plural Quantification [2008], 2.4) | |
| A reaction: [Summary; he cites Boolos as a notable rejector] Linnebo observes that Icelandic contains a word 'tvennir' which means 'two pairs of'. |
| 10639 | Plural quantification may allow a monadic second-order theory with first-order ontology [Linnebo] |
| Full Idea: Plural quantification seems to offer ontological economy. We can pay the price of a mere first-order theory and then use plural quantification to get for free the corresponding monadic second-order theory, which would be an ontological bargain. | |
| From: Øystein Linnebo (Plural Quantification [2008], 4.4) | |
| A reaction: [He mentions Hellman's modal structuralism in mathematics] |
| 10635 | Second-order quantification and plural quantification are different [Linnebo] |
| Full Idea: Second-order quantification and plural quantification are generally regarded as different forms of quantification. | |
| From: Øystein Linnebo (Plural Quantification [2008], 2) |
| 10641 | Traditionally we eliminate plurals by quantifying over sets [Linnebo] |
| Full Idea: The traditional view in analytic philosophy has been that all plural locutions should be paraphrased away by quantifying over sets, though Boolos and other objected that this is unnatural and unnecessary. | |
| From: Øystein Linnebo (Plural Quantification [2008], 5) |
| 10643 | We speak of a theory's 'ideological commitments' as well as its 'ontological commitments' [Linnebo] |
| Full Idea: Some philosophers speak about a theory's 'ideological commitments' and not just about its 'ontological commitments'. | |
| From: Øystein Linnebo (Plural Quantification [2008], 5.4) | |
| A reaction: This is a third strategy for possibly evading one's ontological duty, along with fiddling with the words 'exist' or 'object'. An ideological commitment to something to which one is not actually ontologically committed conjures up stupidity and dogma. |
| 10637 | Ordinary speakers posit objects without concern for ontology [Linnebo] |
| Full Idea: Maybe ordinary speakers aren't very concerned about their ontological commitments, and sometimes find it convenient to posit objects. | |
| From: Øystein Linnebo (Plural Quantification [2008], 2.4) | |
| A reaction: I think this is the whole truth about the ontological commitment of ordinary language. We bring abstraction under control by pretending it is a world of physical objects. The 'left wing' in politics, 'dark deeds', a 'huge difference'. |
| 10634 | Predicates are 'distributive' or 'non-distributive'; do individuals do what the group does? [Linnebo] |
| Full Idea: The predicate 'is on the table' is 'distributive', since some things are on the table if each one is, whereas the predicate 'form a circle' is 'non-distributive', since it is not analytic that when some things form a circle, each one forms a circle. | |
| From: Øystein Linnebo (Plural Quantification [2008], 1.1) | |
| A reaction: The first predicate can have singular or plural subjects, but the second requires a plural subject? Hm. 'The rope forms a circle'. The second is example is not true, as well as not analytic. |
| 23146 | Motives produce intentions, which lead to actions [Driver] |
| Full Idea: Motives will cause persons for form intentions; it is intentions which more directly guide actions. | |
| From: Julia Driver (The Virtues and Human Nature [1996], 3) | |
| A reaction: This is invites the question of whether there is a sharp distinction between the motive and the action. Detectives look for motives, but law courts look for intentions. |
| 23147 | Good intentions are not necessary for virtue [Driver] |
| Full Idea: I deny the claim that good intentions are necessary for virtue. | |
| From: Julia Driver (The Virtues and Human Nature [1996], 3) | |
| A reaction: Presumably one could continually do the right thing, because it was your duty or your job, without actually being well motivated for it. |
| 23144 | Virtue should be defined by consequences, not by states of mind [Driver] |
| Full Idea: The behavioural aspects of virtue are more important than its phenomenology, because virtue is best defined along consequentialist lines. | |
| From: Julia Driver (The Virtues and Human Nature [1996], Intro) | |
| A reaction: This is the thesis of her paper. Quite persuasive. Consequences are, of course, important in all moral theories (even Kant's). She doesn't rely on human nature. The social virtues vary according to the circumstances, such as gossiping in wartime. |
| 23148 | Virtues are character traits or dispositions which produce good consequences for others [Driver] |
| Full Idea: A moral virtue is a character trait (a disposition or cluster of dispositions) which, generally speaking, produces good consequences for others. | |
| From: Julia Driver (The Virtues and Human Nature [1996], 3) | |
| A reaction: There are self-directed virtues, such as keeping fit and healthy. There are virtues for ways to receive the kindness of others. That said, I like this idea. |
| 23150 | Control of pregnancy and knowledge of paternity have downgraded chastity [Driver] |
| Full Idea: Women now have more control over becoming pregnant. Men can now be more certain of paternity, without the constraint of female chastity. Hence chastity is no longer considered a moral virtue. | |
| From: Julia Driver (The Virtues and Human Nature [1996], 5) | |
| A reaction: A persuasive argument that virtues are defined by their consequences (to which I add my example of gossiping in wartime). Different social situations and crises promote or relegate the status of certain virtues (such as food hoarding). |
| 23149 | If generosity systematically turned recipients into parasites, it wouldn't be a virtue [Driver] |
| Full Idea: If generosity towards the needy in the long run produced [social] parasites, and if generosity did this systematically, then it would not be a moral virtue. | |
| From: Julia Driver (The Virtues and Human Nature [1996], 5) | |
| A reaction: A very persuasive example. Hume has similar views - that we encourage those emotions which have good social outcomes. |