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All the ideas for 'Axiomatic Theories of Truth (2005 ver)', 'The Philosophy of History' and 'The Trouble with Possible Worlds'

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19 ideas

2. Reason / B. Laws of Thought / 6. Ockham's Razor
Maybe Ockham's Razor is a purely aesthetic principle [Lycan]
     Full Idea: It might be said that Ockham's Razor is a purely aesthetic principle.
     From: William Lycan (The Trouble with Possible Worlds [1979], 02)
     A reaction: I don't buy this, if it meant to be dismissive of the relevance of the principle to truth. A deep question might be, what is so aesthetically attractive about simplicity? I'm inclined to think that application of the Razor has delivered terrific results.
The Razor seems irrelevant for Meinongians, who allow absolutely everything to exist [Lycan]
     Full Idea: A Meinongian has already posited everything that could, or even could not, be; how, then, can any subsequent brandishing of Ockham's Razor be to the point?
     From: William Lycan (The Trouble with Possible Worlds [1979], 02)
     A reaction: See the ideas of Alexius Meinong. Presumably these crazy Meinongians must make some distinction between what actually exists in front of your nose, and the rest. So the Razor can use that distinction too.
3. Truth / A. Truth Problems / 2. Defining Truth
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.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
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.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
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]
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.
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)
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.
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
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'.
4. Formal Logic / F. Set Theory ST / 1. Set Theory
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)
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
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.
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
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.
9. Objects / A. Existence of Objects / 4. Impossible objects
Maybe non-existent objects are sets of properties [Lycan]
     Full Idea: Meinong's Objects have sometimes been construed as sets of properties.
     From: William Lycan (The Trouble with Possible Worlds [1979], 09)
     A reaction: [Lycan cites Castaņeda and T.Parsons] You still seem to have the problem with any 'bundle' theory of anything. A non-existent object is as much intended to be an object as anything on my desk right now. It just fails to be.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Treating possible worlds as mental needs more actual mental events [Lycan]
     Full Idea: A mentalistic approach to possible worlds is daunted by the paucity of actual mental events.
     From: William Lycan (The Trouble with Possible Worlds [1979], 09)
     A reaction: Why do they have to be actual, any more than memories have to be conscious? The mental events just need to be available when you need them. They are never all required simultaneously. This isn't mathematical logic!
Possible worlds must be made of intensional objects like propositions or properties [Lycan]
     Full Idea: I believe the only promising choice of actual entities to serve as 'worlds' is that of sets of intensional objects, such as propositions or properties with stipulated interrelations.
     From: William Lycan (The Trouble with Possible Worlds [1979], 12)
     A reaction: This is mainly in response to Lewis's construction of them out of actual concrete objects. It strikes me as a bogus problem. It is just a convenient way to think precisely about possibilities, and occasionally outruns our mental capacity.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
If 'worlds' are sentences, and possibility their consistency, consistency may rely on possibility [Lycan]
     Full Idea: If a 'world' is understood as a set of sentences, then possibility may be understood as consistency, ...but this seems circular, in that 'consistency' of sentences cannot adequately be defined save in terms of possibility.
     From: William Lycan (The Trouble with Possible Worlds [1979], 09)
     A reaction: [Carnap and Hintikka propose the view, Lewis 'Counterfactuals' p.85 objects] Worlds as sentences is not, of course, the same as worlds as propositions. There is a lot of circularity around in 'possible' worlds.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Man is God if he raises himself, by denying his nature and finitude [Hegel]
     Full Idea: Man is only God in so far as he negates the natural existence and finitude of his spirit and raises himself to God.
     From: Georg W.F.Hegel (The Philosophy of History [1840], p.324), quoted by Stephen Houlgate - An Introduction to Hegel 10 'God'
     A reaction: I suspect that it was ideas like this which motivated Nietzsche - denial of what we are, in the name of some idle daydream. I personally have no idea how to negate my natural existence or my finitude.
25. Social Practice / A. Freedoms / 1. Slavery
State slavery is a phase of education, moving towards a full culture [Hegel]
     Full Idea: Because slavery exists in states, it is a phase of advance from the merely isolated sensual existence - a phase of education - a mode of becoming participant in a higher morality and the culture connected with it.
     From: Georg W.F.Hegel (The Philosophy of History [1840], p.98), quoted by Stephen Houlgate - An Introduction to Hegel 08 'Rights'
     A reaction: [He adds that slavery should be removed slowly, not suddenly] A nicely provocative thought. Is it better to participate in something grand (like pyramid building) as a slave, or drift in dull isolation? How long should this 'phase' last?
Slavery is unjust, because humanity is essentially free [Hegel]
     Full Idea: Slavery is in and for itself an injustice, for the essence of humanity is freedom.
     From: Georg W.F.Hegel (The Philosophy of History [1840], p.99), quoted by Stephen Houlgate - An Introduction to Hegel 08 'Rights'
     A reaction: This is a corrective to Idea 12783, which offers a defence of the reality of historical slavery. That seemed to depend on some notion that each phase of history is necessary, which is implausible.