19 ideas
| 17082 | Paradox: why do you analyse if you know it, and how do you analyse if you don't? [Ruben] |
| Full Idea: The alleged paradox of analysis asserts that if one knew what was involved in the concept, one would not need the analysis; if one did not know what was involved in the concept, no analysis could be forthcoming. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 1) | |
| A reaction: This is the sort of problem that seemed to bug Plato a lot. You certainly can't analyse something if you don't understand it, but it seems obvious that you can illuminatingly analyse something of which you have a reasonable understanding. |
| 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) |
| 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. |
| 17087 | The 'symmetry thesis' says explanation and prediction only differ pragmatically [Ruben] |
| Full Idea: The 'symmetry thesis' holds that there is only a pragmatic, or epistemic, but no logical, difference between explaining and predicting. …The only difference is in what the producer of the deduction knows just before the deduction is produced. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 4) | |
| A reaction: He cites Mill has holding this view. It seems elementary to me that I can explain something but not predict it, or predict it but not explain it. The latter case is just Humean habitual induction. |
| 17081 | Usually explanations just involve giving information, with no reference to the act of explanation [Ruben] |
| Full Idea: Plato, Aristotle, Mill and Hempel believed that an explanatory product can be characterized solely in terms of the kind of information it conveys, no reference to the act of explaining being required. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 1) | |
| A reaction: Achinstein says it's about acts, because the same information could be an explanation, or a critique, or some other act. Ruben disagrees, and so do I. |
| 17092 | An explanation needs the world to have an appropriate structure [Ruben] |
| Full Idea: Objects or events in the world must really stand in some appropriate 'structural' relation before explanation is possible. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 7) | |
| A reaction: An important point. These days people talk of 'dependence relations'. Some sort of structure to reality (mainly imposed by the direction of time and causation, I would have thought) is a prerequisite of finding a direction to explanation. |
| 17090 | Most explanations are just sentences, not arguments [Ruben] |
| Full Idea: Typically, full explanations are not arguments, but singular sentences, or conjunctions thereof. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 6) | |
| A reaction: This is mainly objecting to the claim that explanations are deductions from laws and facts. I agree with Ruben. Explanations are just information, I think. Of course, Aristotle's demonstrations are arguments. |
| 17094 | The causal theory of explanation neglects determinations which are not causal [Ruben] |
| Full Idea: The fault of the causal theory of explanation was to overlook the fact that there are more ways of making something what it is or being responsible for it than by causing it. …Causation is a particular type of determinative relation. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 7) | |
| A reaction: The only thing I can think of is that certain abstract facts are 'determined' by other abtract facts, without being 'caused' by them. A useful word. |
| 17088 | Reducing one science to another is often said to be the perfect explanation [Ruben] |
| Full Idea: The reduction of one science to another has often been taken as paradigmatic of explanation. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 5) | |
| A reaction: It seems fairly obvious that the total reduction of chemistry to physics would involve the elimination of all the current concepts of chemistry. Could this possibly enhance our understanding of chemistry? I would have thought not. |
| 17089 | Facts explain facts, but only if they are conceptualised or named appropriately [Ruben] |
| Full Idea: Facts explain facts only when the features and the individuals the facts are about are appropriately conceptualized or named. | |
| From: David-Hillel Ruben (Explaining Explanation [1990], Ch 5) | |
| A reaction: He has a nice example that 'Cicero's speeches stop in 43 BCE' isn't explained by 'Tully died then', if you don't know that Cicero was Tully. Ruben is not defending pragmatic explanation, but to this extent he must be right. |
| 23221 | The brain, and all the mental events within it, consists entirely of sensitive and rational matter [Cavendish] |
| Full Idea: Sensitive and rational matter …makes not only the Brain, but all Thoughts, Conceptions, Imaginations, Fancy, Understanding, Memory, Remembrance, and whatsoever motions are in the Head or Brain. | |
| From: Margaret Cavendish (Philosophical Letters [1664], p.185), quoted by Matthew Cobb - The Idea of the Brain 2 | |
| A reaction: Judging by the date of this, and that she is a Cavendish, the influence of Hobbes must be strong, which was brave in 1664. A very strong statement of reductive physicalism, making sure that nothing is left out. |