Combining Texts

All the ideas for 'On the Question of Absolute Undecidability', 'Metaphysics as a Guide to Morals' and 'The Metaontology of Abstraction'

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17 ideas

2. Reason / F. Fallacies / 1. Fallacy
It is a fallacy to explain the obscure with the even more obscure [Hale/Wright]
     Full Idea: The fallacy of 'ad obscurum per obscurius' is to explain the obscure by appeal to what is more obscure.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §3)
     A reaction: Not strictly a fallacy, so much as an example of inadequate explanation, along with circularity and infinite regresses.
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Mathematical set theory has many plausible stopping points, such as finitism, and predicativism [Koellner]
     Full Idea: There are many coherent stopping points in the hierarchy of increasingly strong mathematical systems, starting with strict finitism, and moving up through predicativism to the higher reaches of set theory.
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], Intro)
'Reflection principles' say the whole truth about sets can't be captured [Koellner]
     Full Idea: Roughly speaking, 'reflection principles' assert that anything true in V [the set hierarchy] falls short of characterising V in that it is true within some earlier level.
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], 2.1)
5. Theory of Logic / F. Referring in Logic / 1. Naming / d. Singular terms
Singular terms refer if they make certain atomic statements true [Hale/Wright]
     Full Idea: Anyone should agree that a justification for regarding a singular term as having objectual reference is provided just as soon as one has justification for regarding as true certain atomic statements in which it functions as a singular term.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §9)
     A reaction: The meat of this idea is hidden in the word 'certain'. See Idea 10314 for Hale's explanation. Without that, the proposal strikes me as absurd.
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
We have no argument to show a statement is absolutely undecidable [Koellner]
     Full Idea: There is at present no solid argument to the effect that a given statement is absolutely undecidable.
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], 5.3)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
There are at least eleven types of large cardinal, of increasing logical strength [Koellner]
     Full Idea: Some of the standard large cardinals (in order of increasing (logical) strength) are: inaccessible, Mahlo, weakly compact, indescribable, Erdös, measurable, strong, Wodin, supercompact, huge etc. (...and ineffable).
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], 1.4)
     A reaction: [I don't understand how cardinals can have 'logical strength', but I pass it on anyway]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
PA is consistent as far as we can accept, and we expand axioms to overcome limitations [Koellner]
     Full Idea: To the extent that we are justified in accepting Peano Arithmetic we are justified in accepting its consistency, and so we know how to expand the axiom system so as to overcome the limitation [of Gödel's Second Theorem].
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], 1.1)
     A reaction: Each expansion brings a limitation, but then you can expand again.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Arithmetical undecidability is always settled at the next stage up [Koellner]
     Full Idea: The arithmetical instances of undecidability that arise at one stage of the hierarchy are settled at the next.
     From: Peter Koellner (On the Question of Absolute Undecidability [2006], 1.4)
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Neo-Fregeanism might be better with truth-makers, rather than quantifier commitment [Hale/Wright]
     Full Idea: A third way has been offered to 'make sense' of neo-Fregeanism: we should reject Quine's well-known criterion of ontological commitment in favour of one based on 'truth-maker theory'.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §4 n19)
     A reaction: [The cite Ross Cameron for this] They reject this proposal, on the grounds that truth-maker theory is not sufficient to fix the grounding truth-conditions of statements.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Are neo-Fregeans 'maximalists' - that everything which can exist does exist? [Hale/Wright]
     Full Idea: It is claimed that neo-Fregeans are committed to 'maximalism' - that whatever can exist does.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §4)
     A reaction: [The cite Eklund] They observe that maximalism denies contingent non-existence (of the £20 note I haven't got). There seems to be the related problem of 'hyperinflation', that if abstract objects are generated logically, the process is unstoppable.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
The identity of Pegasus with Pegasus may be true, despite the non-existence [Hale/Wright]
     Full Idea: Identity is sometimes read so that 'Pegasus is Pegasus' expresses a truth, the non-existence of any winged horse notwithstanding.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §5)
     A reaction: This would give you ontological commitment to truth, without commitment to existence. It undercuts the use of identity statements as the basis of existence claims, which was Frege's strategy.
8. Modes of Existence / B. Properties / 3. Types of Properties
Maybe we have abundant properties for semantics, and sparse properties for ontology [Hale/Wright]
     Full Idea: There is a compatibilist view which says that it is for the abundant properties to play the role of 'bedeutungen' in semantic theory, and the sparse ones to address certain metaphysical concerns.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §9)
     A reaction: Only a philosopher could live with the word 'property' having utterly different extensions in different areas of discourse. They similarly bifurcate words like 'object' and 'exist'. Call properties 'quasi-properties' and I might join in.
8. Modes of Existence / B. Properties / 10. Properties as Predicates
A successful predicate guarantees the existence of a property - the way of being it expresses [Hale/Wright]
     Full Idea: The good standing of a predicate is already trivially sufficient to ensure the existence of an associated property, a (perhaps complex) way of being which the predicate serves to express.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §9)
     A reaction: 'Way of being' is interesting. Is 'being near Trafalgar Sq' a way of being? I take properties to be 'features', which seems to give a clearer way of demarcating them. They say they are talking about 'abundant' (rather than 'sparse') properties.
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
We know perfection when we see what is imperfect [Murdoch]
     Full Idea: We know of perfection as we look upon what is imperfect.
     From: Iris Murdoch (Metaphysics as a Guide to Morals [1992], 13)
     A reaction: This is in the context of a discussion of the ontological argument for God's existence, but I seize on it as a nice expression of the idealisation capacity of our minds. The alternative is that perfection is innate idea, since we aren't seeing it.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstractionism needs existential commitment and uniform truth-conditions [Hale/Wright]
     Full Idea: Abstractionism needs a face-value, existentially committed reading of the terms occurring on the left-hand sides together with sameness of truth-conditions across the biconditional.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §5)
     A reaction: They employ 'abstractionism' to mean their logical Fregean strategy for defining abstractions, not to mean the older psychological account. Thus the truth-conditions for being 'parallel' and for having the 'same direction' must be consistent.
Equivalence abstraction refers to objects otherwise beyond our grasp [Hale/Wright]
     Full Idea: Abstraction principles purport to introduce fundamental means of reference to a range of objects, to which there is accordingly no presumption that we have any prior or independent means of reference.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §8)
     A reaction: There's the rub! They make it sound like a virtue, that we open up yet another heaven of abstract toys to play with. As fictions, they are indeed exciting new fun. As platonic discoveries they strike me as Cloud-Cuckoo Land.
19. Language / B. Reference / 4. Descriptive Reference / a. Sense and reference
Reference needs truth as well as sense [Hale/Wright]
     Full Idea: It takes, over and above the possession of sense, the truth of relevant contexts to ensure reference.
     From: B Hale / C Wright (The Metaontology of Abstraction [2009], §9)
     A reaction: Reference purely through sense was discredited by Kripke. The present idea challenges Kripke's baptismal realist approach. How do you 'baptise' an abstract object? But isn't reference needed prior to the establishment of truth?