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All the ideas for 'The Nature of Things', 'Axiomatic Theories of Truth (2013 ver)' and 'The Coherence Theory of Truth'

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25 ideas

3. Truth / A. Truth Problems / 2. Defining Truth
19125 If we define truth, we can eliminate it [Halbach/Leigh]
     Full Idea: If truth can be explicitly defined, it can be eliminated.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.3)
     A reaction: That we could just say p corresponds to the facts, or p coheres with our accepted beliefs, or p is the aim of our enquiries, and never mention the word 'true'. Definition is a strategy for reduction or elimination.
3. Truth / B. Truthmakers / 12. Rejecting Truthmakers
19079 For idealists reality is like a collection of beliefs, so truths and truthmakers are not distinct [Young,JO]
     Full Idea: Idealists do not believe that there is an ontological distinction between beliefs and what makes beliefs true. From their perspective, reality is something like a collection of beliefs.
     From: James O. Young (The Coherence Theory of Truth [2013], §2.1)
     A reaction: This doesn't seem to me to wholly reject truthmakers, since beliefs can still be truthmakers for one another. This is something like Davidson's view, that only beliefs can justify other beliefs.
3. Truth / D. Coherence Truth / 1. Coherence Truth
19076 Coherence theories differ over the coherence relation, and over the set of proposition with which to cohere [Young,JO]
     Full Idea: Coherence theories of truth differ on their accounts of the coherence relation, and on their accounts of the set (or sets) of propositions with which true propositions occur (the 'specified set').
     From: James O. Young (The Coherence Theory of Truth [2013], §1)
     A reaction: Coherence is clearly more than consistency or mutual entailment, and I like to invoke explanation. The set has to be large, or the theory is absurd (as two absurdities can 'cohere'). So very large, or very very large, or maximally large?
19077 Two propositions could be consistent with your set, but inconsistent with one another [Young,JO]
     Full Idea: It is unsatisfactory for the coherence relation to be consistency, because two propositions could be consistent with a 'specified set', and yet be inconsistent with each other. That would imply they are both true, which is impossible.
     From: James O. Young (The Coherence Theory of Truth [2013], §1)
     A reaction: I'm not convinced by this. You first accept P because it is consistent with the set; then Q turns up, which is consistent with everything in the set except P. So you have to choose between them, and might eject P. Your set was too small.
19078 Coherence with actual beliefs, or our best beliefs, or ultimate ideal beliefs? [Young,JO]
     Full Idea: One extreme for the specified set is the largest consistent set of propositions currently believed by actual people. A moderate position makes it the limit of people's enquiries. The other extreme is what would be believed by an omniscient being.
     From: James O. Young (The Coherence Theory of Truth [2013], §1)
     A reaction: One not considered is the set of propositions believed by each individual person. Thoroughgoing relativists might well embrace that one. Peirce and Putnam liked the moderate one. I'm taken with the last one, since truth is an ideal, not a phenomenon.
19084 Coherent truth is not with an arbitrary set of beliefs, but with a set which people actually do believe [Young,JO]
     Full Idea: It must be remembered that coherentists do not believe that the truth of a proposition consists in coherence with an arbitrarily chosen set of propositions; the coherence is with a set of beliefs, or a set of propositions held to be true.
     From: James O. Young (The Coherence Theory of Truth [2013], §3.1)
     A reaction: This is a very good response to critics who cite bizarre sets of beliefs which happen to have internal coherence. You have to ask why they are not actually believed, and the answer must be that the coherence is not extensive enough.
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
19083 How do you identify the best coherence set; and aren't there truths which don't cohere? [Young,JO]
     Full Idea: The two main objections to the coherence theory of truth are that there is no way to identify the 'specified set' of propositions without contradiction, ...and that some propositions are true which cohere with no set of beliefs.
     From: James O. Young (The Coherence Theory of Truth [2013], §3.1/2)
     A reaction: The point of the first is that you need a prior knowledge of truth to say which of two sets is the better one. The second one is thinking of long-lost tiny details from the past, which seem to be true without evidence. A huge set might beat the first one.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
19128 If a language cannot name all objects, then satisfaction must be used, instead of unary truth [Halbach/Leigh]
     Full Idea: If axioms are formulated for a language (such as set theory) that lacks names for all objects, then they require the use of a satisfaction relation rather than a unary truth predicate.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 3.3)
     A reaction: I take it this is an important idea for understanding why Tarski developed his account of truth based on satisfaction.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
19120 Semantic theories need a powerful metalanguage, typically including set theory [Halbach/Leigh]
     Full Idea: Semantic approaches to truth usually necessitate the use of a metalanguage that is more powerful than the object-language for which it provides a semantics. It is usually taken to include set theory.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1)
     A reaction: This is a motivation for developing an axiomatic account of truth, that moves it into the object language.
3. Truth / F. Semantic Truth / 2. Semantic Truth
19127 The T-sentences are deductively weak, and also not deductively conservative [Halbach/Leigh]
     Full Idea: Although the theory is materially adequate, Tarski thought that the T-sentences are deductively too weak. …Also it seems that the T-sentences are not conservative, because they prove in PA that 0=0 and ¬0=0 are different, so at least two objects exist.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 3.2)
     A reaction: They are weak because they can't prove completeness. This idea give two reasons for looking for a better theory of truth.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
19124 A natural theory of truth plays the role of reflection principles, establishing arithmetic's soundness [Halbach/Leigh]
     Full Idea: If a natural theory of truth is added to Peano Arithmetic, it is not necessary to add explicity global reflection principles to assert soundness, as the truth theory proves them. Truth theories thus prove soundess, and allows its expression.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.2)
     A reaction: This seems like a big attraction of axiomatic theories of truth for students of metamathematics.
19126 If deflationary truth is not explanatory, truth axioms should be 'conservative', proving nothing new [Halbach/Leigh]
     Full Idea: If truth does not have any explanatory force, as some deflationists claim, the axioms of truth should not allow us to prove any new theorems that do not involve the truth predicate. That is, a deflationary axiomatisation of truth should be 'conservative'.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.3)
     A reaction: So does truth have 'explanatory force'? These guys are interested in explaining theorems of arithmetic, but I'm more interested in real life. People do daft things because they have daft beliefs. Logic should be neutral, but truth has values?
3. Truth / G. Axiomatic Truth / 2. FS Truth Axioms
19129 The FS axioms use classical logical, but are not fully consistent [Halbach/Leigh]
     Full Idea: It is a virtue of the Friedman-Sheard axiomatisation that it is thoroughly classical in its logic. Its drawback is that it is ω-inconsistent. That is, it proves &exists;x¬φ(x), but proves also φ(0), φ(1), φ(2), …
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 4.3)
     A reaction: It seems the theory is complete (and presumably sound), yet not fully consistent. FS also proves the finite levels of Tarski's hierarchy, but not the transfinite levels.
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
19130 KF is formulated in classical logic, but describes non-classical truth, which allows truth-value gluts [Halbach/Leigh]
     Full Idea: KF is formulated in classical logic, but describes a non-classical notion of truth. It allow truth-value gluts, making some sentences (such as the Liar) both true and not-true. Some authors add an axiom ruling out such gluts.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 4.4)
     A reaction: [summary, which I hope is correct! Stanford is not wholly clear]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
19075 Deflationary theories reject analysis of truth in terms of truth-conditions [Young,JO]
     Full Idea: Unlike deflationary theories, the coherence and correspondence theories both hold that truth is a property of propositions that can be analyzed in terms of the sorts of truth-conditions propositions have, and the relation propositions stand in to them.
     From: James O. Young (The Coherence Theory of Truth [2013], Intro)
     A reaction: This is presumably because deflationary theories reject the external relations of a proposition as a feature of its truth. This evidently leaves them in need of a theory of meaning, which may be fairly minimal. Horwich would be an example.
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
9406 A class is natural when everybody can spot further members of it [Quinton]
     Full Idea: To say that a class is natural is to say that when some of its members are shown to people they pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: He concedes a number of problems with his view, but I admire his attempt to at least begin to distinguish the natural (real!) classes from the ersatz ones. A mention of causal powers would greatly improve his story.
7. Existence / E. Categories / 5. Category Anti-Realism
15730 Extreme nominalists say all classification is arbitrary convention [Quinton]
     Full Idea: Pure, extreme nominalism sees all classification as the product of arbitrary convention.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I'm not sure what the word 'arbitrary' is doing there. Nominalists are not daft, and if they can classify any way they like, they are not likely to choose an 'arbitrary' system. Pragmatism tells the right story here.
8. Modes of Existence / B. Properties / 5. Natural Properties
15728 The naturalness of a class depends as much on the observers as on the objects [Quinton]
     Full Idea: The naturalness of a class depends as essentially on the nature of the observers who classify as it does on the nature of the objects that they classify. ...It depends on our perceptual apparatus, and on our relatively mutable needs and interests.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: This seems to translate 'natural' as 'natural for us', which is not much use to scientists, who spend quite a lot of effort combating folk wisdom. Do desirable sports cars constitute a natural class?
9407 Properties imply natural classes which can be picked out by everybody [Quinton]
     Full Idea: To say there are properties is to say there are natural classes, classes introduction to some of whose members enables people to pick out others without hesitation and in agreement.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: Aristotle would like this approach, but it doesn't find many friends among modern logician/philosophers. We should go on to ask why people agree on these things. Causal powers will then come into it.
8. Modes of Existence / B. Properties / 12. Denial of Properties
19121 We can reduce properties to true formulas [Halbach/Leigh]
     Full Idea: One might say that 'x is a poor philosopher' is true of Tom instead of saying that Tom has the property of being a poor philosopher. We quantify over formulas instead of over definable properties, and thus reduce properties to truth.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.1)
     A reaction: [compressed] This stuff is difficult (because the axioms are complex and hard to compare), but I am excited (yes!) about this idea. Their point is that you need a truth predicate within the object language for this, which disquotational truth forbids.
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
15729 Uninstantiated properties must be defined using the instantiated ones [Quinton]
     Full Idea: Properties that have no concrete instances must be defined in terms of those that have.
     From: Anthony Quinton (The Nature of Things [1973], 9 'Nat')
     A reaction: I wonder what the dodo used to smell like?
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
19122 Nominalists can reduce theories of properties or sets to harmless axiomatic truth theories [Halbach/Leigh]
     Full Idea: The reduction of second-order theories (of properties or sets) to axiomatic theories of truth is a form of reductive nominalism, replacing existence assumptions (e.g. comprehension axioms) by innocuous assumptions about the truth predicate.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.1)
     A reaction: I'm currently thinking that axiomatic theories of truth are the most exciting development in contemporary philosophy. See Halbach and Horsten.
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
8520 An individual is a union of a group of qualities and a position [Quinton, by Campbell,K]
     Full Idea: Quinton proposes that an individual is a union of a group of qualities and a position.
     From: report of Anthony Quinton (The Nature of Things [1973], Pt I) by Keith Campbell - The Metaphysic of Abstract Particulars §5
     A reaction: This seems the obvious defence of a bundle account of objects against the charge that indiscernibles would have to be identical. It introduces, however, 'positions' into the ontology, but maybe that price must be paid. Materialism needs space.
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
19074 Are truth-condtions other propositions (coherence) or features of the world (correspondence)? [Young,JO]
     Full Idea: For the coherence theory of truth, the truth conditions of propositions consist in other propositions. The correspondence theory, in contrast, states that the truth conditions of propositions are ... objective features of the world.
     From: James O. Young (The Coherence Theory of Truth [2013], Intro)
     A reaction: It is obviously rather important for your truth-conditions theory of meaning that you are clear about your theory of truth. A correspondence theory is evidently taken for granted, even in possible worlds versions.
19082 Coherence truth suggests truth-condtions are assertion-conditions, which need knowledge of justification [Young,JO]
     Full Idea: Coherence theorists can argue that the truth conditions of a proposition are those under which speakers tend to assert it, ...and that speakers can only make a practice of asserting a proposition under conditions they can recognise as justifying it.
     From: James O. Young (The Coherence Theory of Truth [2013], §2.2)
     A reaction: [compressed] This sounds rather verificationist, and hence wrong, since if you then asserted anything for which you didn't know the justification, that would remove its truth, and thus make it meaningless.