19 ideas
| 19259 | If 2-D conceivability can a priori show possibilities, this is a defence of conceptual analysis [Vaidya] |
| Full Idea: Chalmers' two-dimensional conceivability account of possibility offers a defence of a priori conceptual analysis, and foundations on which a priori philosophy can be furthered. | |
| From: Anand Vaidya (Understanding and Essence [2010], Intro) | |
| A reaction: I think I prefer Williamson's more scientific account of possibility through counterfactual conceivability, rather than Chalmers' optimistic a priori account. Deep topic, though, and the jury is still out. |
| 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. |
| 4032 | The problem of universals is how many particulars can all be of the same 'type' [Armstrong] |
| Full Idea: The problem of universals is the problem of how numerically different particulars can nevertheless be identical in nature, all be of the same 'type'. | |
| From: David M. Armstrong (Nominalism and Realism [1978], p.41), quoted by DH Mellor / A Oliver - Introduction to 'Properties' §7 | |
| A reaction: A nice statement of the problem. As usual, the question is whether the 'sameness' is a feature of nature, or a product of human thought |
| 19262 | Essential properties are necessary, but necessary properties may not be essential [Vaidya] |
| Full Idea: When P is an essence of O it follows that P is a necessary property of O. However, P can be a necessary property of O without being an essence of O. | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Knowledge') | |
| A reaction: This summarises the Kit Fine view with which I sympathise. However, I dislike presenting essence as a mere list of properties, which is only done for the convenience of logicians. But was Jessie Owens a great athlete after he lost his speed? |
| 19267 | Define conceivable; how reliable is it; does inconceivability help; and what type of possibility results? [Vaidya] |
| Full Idea: Conceivability as evidence for possibility needs four interpretations. How is 'conceivable' defined or explained? How strongly is the idea endorsed? How does inconceivability fit in? And what kind of possibility (logical, physical etc) is implied? | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Application') | |
| A reaction: [some compression] Williamson's counterfactual account helps with the first one. The strength largely depends on whether your conceptions are well informed. Inconceivability may be your own failure. All types of possibility can be implied. |
| 19268 | Inconceivability (implying impossibility) may be failure to conceive, or incoherence [Vaidya] |
| Full Idea: If we aim to derive impossibility from inconceivability, we may either face a failure to conceive something, or arrive at a state of incoherence in conceiving. | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Application') | |
| A reaction: [summary] Thus I can't manage to conceive a multi-dimensional hypercube, but I don't even try to conceive a circular square. In both cases, we must consider whether the inconceivability results from our own inadequacy, rather than from the facts. |
| 19265 | Can you possess objective understanding without realising it? [Vaidya] |
| Full Idea: Is it possible for an individual to possess objectual understanding without knowing they possess the objectual understanding? | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Objections') | |
| A reaction: Hm. A nice new question to loose sleep over. We can't demand a regress of meta-understandings, so at some point you just understand. Birds understand nests. Equivalent: can you understand P, but can't explain P? Skilled, but inarticulate. |
| 19260 | Gettier deductive justifications split the justification from the truthmaker [Vaidya] |
| Full Idea: In the Gettier case of deductive justification, what we have is a separation between the source of the justification and the truthmaker for the belief. | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Distinction') | |
| A reaction: A very illuminating insight into the Gettier problem. As a fan of truthmakers, I'm wondering if this might quickly solve it. |
| 19266 | In a disjunctive case, the justification comes from one side, and the truth from the other [Vaidya] |
| Full Idea: The disjunctive belief that 'either Jones owns a Ford or Brown is in Barcelona', which Smith believes, derives its justification from the left disjunct, and its truth from the right disjunct. | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Application') | |
| A reaction: The example is from Gettier's original article. Have we finally got a decent account of the original Gettier problem, after fifty years of debate? Philosophical moves with delightful slowness. |
| 19264 | Aboutness is always intended, and cannot be accidental [Vaidya] |
| Full Idea: A representation cannot accidentally be about an object. Aboutness is in general an intentional relation. | |
| From: Anand Vaidya (Understanding and Essence [2010], 'Objections') | |
| A reaction: 'Intentional' with a 't', not with an 's'. This strikes me as important. Critics dislike the idea of 'representation' because if you passively place a representation and its subject together, what makes the image do the representing job? Answer: I do! |