Combining Texts

All the ideas for 'fragments/reports', 'Axiomatic Theories of Truth (2013 ver)' and 'Dion and Theon: an essentialist solution'

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19 ideas

3. Truth / A. Truth Problems / 2. Defining Truth
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 / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
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
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
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
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.
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
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
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]
8. Modes of Existence / B. Properties / 12. Denial of Properties
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 / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
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 / e. Individuation by kind
Persistence conditions cannot contradict, so there must be a 'dominant sortal' [Burke,M, by Hawley]
     Full Idea: Burke says a single object cannot have incompatible persistence conditions, for this would entail that there are events in which the object would both survive and perish. He says one sortal 'dominates' the other (sweater dominates thread).
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Katherine Hawley - How Things Persist 5.3
     A reaction: This I take to be the most extreme version of sortal essentialism, and strikes me as incredibly gerrymandered and unacceptable. It is just too anthropocentric to count as genuine metaphysics. I may care more about the thread.
The 'dominant' of two coinciding sortals is the one that entails the widest range of properties [Burke,M, by Sider]
     Full Idea: Burke claims that the 'dominant' sortal is the one whose satisfaction entails possession of the widest range of properties. For example, the statue (unlike the lump of clay) also possesses aesthetic properties, and hence is dominant.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Theodore Sider - Four Dimensionalism 5.4
     A reaction: [there are three papers by Burke on this; see all the quotations from Burke] Presumably one sortal could entail a single very important property, and the other sortal entail a huge range of trivial properties. What does being a 'thing' entail?
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
'The rock' either refers to an object, or to a collection of parts, or to some stuff [Burke,M, by Wasserman]
     Full Idea: Burke distinguishes three different readings of 'the rock'. It can be a singular description denoting an object, or a plural description denoting all the little pieces of rock, or a mass description the relevant rocky stuff.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Ryan Wasserman - Material Constitution 5
     A reaction: Idea 16068 is an objection to the second reading. Only the first reading seems plausible, so we must just get over all the difficulties philosophers have unearthed about knowing exactly what an 'object' is. I offer you essentialism. Rocks have unity.
9. Objects / B. Unity of Objects / 3. Unity Problems / b. Cat and its tail
Tib goes out of existence when the tail is lost, because Tib was never the 'cat' [Burke,M, by Sider]
     Full Idea: Burke argues that Tib (the whole cat apart from its tail) goes out of existence when the tail is lost. His essentialist principle is that if something is ever of a particular sort (such as 'cat') then it is always of that sort. Tib is not initially a cat.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Theodore Sider - Four Dimensionalism 5.4
     A reaction: This I take to be a souped up version of Wiggins, and I just don't buy that identity conditions are decided by sortals, when it seems obvious that sortals are parasitic on identities.
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
Sculpting a lump of clay destroys one object, and replaces it with another one [Burke,M, by Wasserman]
     Full Idea: On Burke's view, the process of sculpting a lump of clay into a statue destroys one object (a mere lump of clay) and replaces it with another (a statue).
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Ryan Wasserman - Material Constitution 5
     A reaction: There is something right about this, but how many intermediate objects are created during the transition. It seems to make the notion of an object very conventional.
Burke says when two object coincide, one of them is destroyed in the process [Burke,M, by Hawley]
     Full Idea: Michael Burke argues that a sweater is identical with the thread that consitutes it, that both were created at the moment when they began to coincide, and that the original thread was destroyed in the process.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Katherine Hawley - How Things Persist 5.3
     A reaction: [Burke's ideas are spread over three articles] It is the thread which is destroyed, because the sweater is the 'dominant sortal' (which strikes me as a particularlyd desperate concept).
Maybe the clay becomes a different lump when it becomes a statue [Burke,M, by Koslicki]
     Full Idea: Burke has argued in a series of papers that the lump of clay which constitutes the statue is numerically distinct from the lump of clay which exists before or after the statue exists. The first is a statue, while the second is merely a lump of clay.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Kathrin Koslicki - The Structure of Objects
     A reaction: Koslicki objects that this introduces radically different persistence conditions from normal. It would mean that a pile of sugar was a different pile of sugar every time a grain moved (even slightly). You couldn't step into the same sugar twice.
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
Two entities can coincide as one, but only one of them (the dominant sortal) fixes persistence conditions [Burke,M, by Sider]
     Full Idea: Michael Burke has given an account that avoids distinguishing coinciding entities. ...The statue/lump satisfies both 'lump' and 'statue', but only the latter determines that object's persistence conditions, and so is that object's 'dominant sortal'.
     From: report of Michael Burke (Dion and Theon: an essentialist solution [1994]) by Theodore Sider - Four Dimensionalism 5.4
     A reaction: Presumably a lump on its own can have its own persistance conditions (as a 'lump'), but those would presumably be lost if you shaped it into a statue. Burke concedes that. Can of worms. Using a book as a doorstop...
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
Musical performance can reveal a range of virtues [Damon of Ath.]
     Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice.
     From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where?