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. |
| 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. |
| 19712 | Maybe there is plain 'animal' knowledge, and clearly justified 'reflective' knowledge [Vahid] |
| Full Idea: There is a distinction between 'animal knowledge' (which requires only apt belief), and 'reflective knowledge' (requiring both apt and justified belief). | |
| From: Hamid Vahid (Externalism/Internalism [2011], 5) | |
| A reaction: [He cites Sosa 1991] My inclination (Idea 19711) was to think of knowledge as a continuum (possibly with a contextual component), and this distinction doesn't change my view, though it makes the point. |
| 19703 | Epistemic is normally marked out from moral or pragmatic justifications by its truth-goal [Vahid] |
| Full Idea: It is widely believed that epistemic justification is distinct from other species of justification such as moral or pragmatic justification in that it is intended to serve the so-called 'truth-goal'. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 1) | |
| A reaction: Kvanvig explicitly argues against this view. He broadens the aims, but it strikes me that other aims are all intertwined with truth in some way, so I find this idea quite plausible. |
| 19705 | 'Mentalist' internalism seems to miss the main point, if it might not involve an agent's access [Vahid] |
| Full Idea: Since mentalism remains neutral on whether mental states need be accessible to an agent ...it does not seem to do justice to the intuitions that drive paradigm internalist positions. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 2 A) | |
| A reaction: The rival view is 'access internalism', which implies that you can act on and take responsibility for your knowledge, because you are aware of its grounding. If animals know things, that might fit the mentalist picture better. |
| 19706 | Strong access internalism needs actual awareness; weak versions need possibility of access [Vahid] |
| Full Idea: A strong form of 'access internalism' is when an agent is required to be actually aware of the conditions that constitute justification; a weaker version loosens the accessibility condition, requiring only the ability to access the justification. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 2 B) | |
| A reaction: The super strong version implies that you probably only know one thing at a time, so it must be nonsense. The weaker version has grey areas. I remember roughly the justification, but not the details. The justification is in my diary. Etc. |
| 19707 | Maybe we need access to our justification, and also to know why it justifies [Vahid] |
| Full Idea: Access internalism may also have a truth-conducive conception of justification, where one should not only know what one's reasons are, but also why one's beliefs are probable on one's reasons. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 2 B) | |
| A reaction: [he cites Bonjour 1985] Sounds reasonable. It would seem odd if you had clear access to the reason, but didn't understand it, because you had just learned it by rote. |
| 19709 | Internalism in epistemology over-emphasises deliberation about beliefs [Vahid] |
| Full Idea: The internalist approach in epistemology seems to suggest an over-inellectualized and deliberative picture of our belief-forming activities. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 2.2 B) | |
| A reaction: This strikes me as confused. The question is not how do I arrive at my beliefs but what justifies my believing them, and what justifies the beliefs in themselves? My head is full of daft beliefs produced by TV advertising. |
| 8875 | Sense experiences must have conceptual content, since they are possible reasons for judgements [Brewer,B] |
| Full Idea: Given that sense experiential states do provide reasons for empirical beliefs, they must have conceptual content, ...where a mental state with conceptual content is one where the content is of a possible judgement by the subject. | |
| From: Bill Brewer (Perceptual experience has conceptual content [2005], I) | |
| A reaction: This is, I believe, wrong. Even complex observations, like a pool of blood, only become reasons when they have been interpreted. Otherwise they are just the raw ingredients of evidence. How could an uninterpreted red patch be a 'reason'? |
| 19704 | Externalism may imply that identical mental states might go with different justifications [Vahid] |
| Full Idea: According to the 'mentalist' version of internalism, an externalist is someone who maintains that two people can be in the same present mental states while one has a justified belief and the other does not. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 2 A) | |
| A reaction: It seems an unlikely coincidence, that we have identical mental states, but your is (say) reliably created but mine isn't. Nevertheless this does seem to be an implication of externalism, though not a definition of it. |
| 19710 | With a counterfactual account of the causal theory, we get knowledge as tracking or sensitive to truth [Vahid] |
| Full Idea: The causal theory of justification was soon replaced by Nozick's construal of knowledge as counterfactually sensitive to its truth value (that is, it tracks truth). A counterfactual theory of causation connects this to the causal theory. | |
| From: Hamid Vahid (Externalism/Internalism [2011], 3) | |
| A reaction: This is presented as an externalist theory, close to the causal theory (and prior to the reliability theory). But how could you be 'sensitive' to a changing truth if the justification was all external? Externally supported beliefs seem ossified. |
| 19711 | Externalism makes the acquisition of knowledge too easy? [Vahid] |
| Full Idea: Internalists say that externalism is inadequate because it makes the obtaining of knowledge and justified beliefs too easy | |
| From: Hamid Vahid (Externalism/Internalism [2011], 4) | |
| A reaction: This looks like a key issue in epistemology. Do children and animals have lots of knowledge, which they soak up unthinkingly, or do only thinking adults really 'know' things? Why not have degrees of knowledge? |