24 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. |
| 8440 | Maybe an event's time of occurrence is essential to it [Bennett] |
| Full Idea: It has been argued that an event's time of occurrence is essential to it. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987], p.221) | |
| A reaction: [He cites Lawrence Lombard] This sound initially implausible, particularly if a rival event happened, say, .1 of a second later than the actual event. It might depend on one's view about determinism. Interesting. |
| 8439 | Maybe each event has only one possible causal history [Bennett] |
| Full Idea: Perhaps it is impossible that an event should have had a causal history different from the one that it actually had. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987], p.220) | |
| A reaction: [He cites van Inwagen for this] The idea is analagous to baptismal accounts of reference. Individuate an event by its history. It might depend (as Davidson implies) on how you describe the event. |
| 16066 | Additional or removal of any part changes a thing, so people are never the same person [Epicharmus] |
| Full Idea: If you add or take away a pebble, the same number does not remain. If you add to a length or cut off from it, the former measure does not remain. So human beings grow or waste away. Both you and I were, and shall be, other men. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B02), quoted by Diogenes Laertius - Lives of Eminent Philosophers 03.12 | |
| A reaction: [The original is in dialogue form from a play. The context is a joke about not paying a debt.] Note the early date for this metaphysical puzzle. My new favourite reply is Chrysippus's Idea 16059; identity actually requires change. |
| 436 | A dog seems handsome to another a dog, and even a pig to another pig [Epicharmus] |
| Full Idea: Dog seems very handsome to dog, and ox to ox, and donkey very handsome to donkey, and even pig to pig. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B05), quoted by (who?) - where? |
| 442 | Pleasures are like pirates - if you are caught they drown you in a sea of pleasures [Epicharmus] |
| Full Idea: Pleasures for mortals are like impious pirates, for the man who is caught by pleasures is immediately drowned in a sea of them. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B44), quoted by (who?) - where? | |
| A reaction: Not all slopes are slippery. Plenty of people hold themselves to strict rules about alcohol or gambling. People have occasional treats. |
| 440 | Hands wash hands; give that you may get [Epicharmus] |
| Full Idea: The hand washes the hand; give something and you may get something. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B30), quoted by (who?) - where? |
| 441 | Against a villain, villainy is not a useless weapon [Epicharmus] |
| Full Idea: Against a villain, villainy is not a useless weapon. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B32), quoted by (who?) - where? |
| 8441 | Delaying a fire doesn't cause it, but hastening it might [Bennett] |
| Full Idea: Although you cannot cause a fire by delaying something's burning, you can cause a fire by hastening something's burning. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987], p.223) | |
| A reaction: A very nice observation which brings out all sorts of problems about identifying causes. Bennett is criticising the counterfactual account. It is part of the problem of pre-emption, where causes are queueing up to produce a given effect. |
| 8436 | Either cause and effect are subsumed under a conditional because of properties, or it is counterfactual [Bennett] |
| Full Idea: We must choose between subsumption and counterfactual analyses of causal statements. The former means that cause and effect have some properties that enables them to be subsumed under a conditional. The latter is just 'if no-c then no-e'. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987], p.217) | |
| A reaction: I have an immediate preference for the former account, which seems to potentially connect it with physics and features of the world which make one thing lead to another. The counterfactual account seems very thin, and is more like mere semantics. |
| 8435 | Causes are between events ('the explosion') or between facts/states of affairs ('a bomb dropped') [Bennett] |
| Full Idea: Theories of causation are split between event and fact/state of affairs theories. The first have the form 'the explosion caused the fire' (perfect nominals) and the second have the form 'the fire started because a bomb dropped' (sentential clauses). | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987]) | |
| A reaction: Surely events must have priority? The form which uses facts is drifting off into explanation, and is much more likely to involve subjective human elements and interpretations. Events are closer to the physics, and the mechanics of what happens. |
| 8437 | The full counterfactual story asserts a series of events, because counterfactuals are not transitive [Bennett] |
| Full Idea: The refinement of a simple counterfactual analysis is to say that cause and effect depend on a series of events. This must be asserted because counterfactual conditionals are well known not to be transitive. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987]) | |
| A reaction: This fills out the theory, but offers another target for critics. If the glue that binds the series is not in the counterfactuals, is it just in the mind of the speaker? How do you decide what's in the series? Cf. deciding offside in football (soccer!). |
| 8438 | A counterfactual about an event implies something about the event's essence [Bennett] |
| Full Idea: Any counterfactual about a particular event implies or presupposes something about the event's essence. | |
| From: Jonathan Bennett (Event Causation: counterfactual analysis [1987], p.219) | |
| A reaction: This is where the counterfactual theory suddenly becomes more interesting, instead of just being a rather bare account of the logical structure of causation. (Bennett offers some discussion of possible essential implications). |
| 439 | God knows everything, and nothing is impossible for him [Epicharmus] |
| Full Idea: Nothing escapes the divine, this you must realise. God himself is our overseer, and nothing is impossible for him. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B23), quoted by (who?) - where? |
| 443 | Human logos is an aspect of divine logos, and is sufficient for successful living [Epicharmus] |
| Full Idea: Man has calculation, but there is also the divine logos. But human logos is sprung from the divine logos, and it brings to each man his means of life, and his maintenance. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B57), quoted by (who?) - where? |