Combining Texts

All the ideas for 'On the Question of Absolute Undecidability', 'Criterion of Validity in Reasoning' and 'Neutral Relations'

unexpand these ideas     |    start again     |     specify just one area for these texts


15 ideas

2. Reason / A. Nature of Reason / 4. Aims of Reason
I reason in order to avoid disappointment and surprise [Peirce]
     Full Idea: I do not reason for the sake of my delight in reasoning, but solely to avoid disappointment and surprise.
     From: Charles Sanders Peirce (Criterion of Validity in Reasoning [1903], I)
     A reaction: Hence Peirce places more emphasis on inductive and abductive reasoning than on deductive reasoning. I have to agree with him. Anyone account of why we reason must have an evolutionary framework. What advantage does reason bestow? It concerns the future.
3. Truth / H. Deflationary Truth / 1. Redundant Truth
That a judgement is true and that we judge it true are quite different things [Peirce]
     Full Idea: Either J and the judgment 'I say that J is true' are the same for all judgments or for none. But if identical, their denials are identical. These are 'J is not true' and 'I do not say that J is true', which are different. No judgment judges itself true.
     From: Charles Sanders Peirce (Criterion of Validity in Reasoning [1903], I)
     A reaction: If you are going to espouse the Ramseyan redundancy view of truth, you had better make sure you are not guilty of the error which Peirce identifies here.
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 / A. Overview of Logic / 3. Value of Logic
Only study logic if you think your own reasoning is deficient [Peirce]
     Full Idea: It is foolish to study logic unless one is persuaded that one's own reasonings are more or less bad.
     From: Charles Sanders Peirce (Criterion of Validity in Reasoning [1903], II)
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)
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
Facts are hard unmoved things, unaffected by what people may think of them [Peirce]
     Full Idea: Facts are hard things which do not consist in my thinking so and so, but stand unmoved by whatever you or I or any man or generations of men may opine about them.
     From: Charles Sanders Peirce (Criterion of Validity in Reasoning [1903], I)
     A reaction: This is my view of facts, with which I am perfectly happy, for all the difficulties involved in individuating facts, and in disentangling them from our own modes of thought and expression. Let us try to establish the facts.
8. Modes of Existence / A. Relations / 1. Nature of Relations
The 'standard' view of relations is that they hold of several objects in a given order [Fine,K]
     Full Idea: The 'standard' view of relations, held by philosophers and logicians alike, is that we may meaningfully talk of a relation holding of several objects in a given order (which works for examples like 'loves' and 'between').
     From: Kit Fine (Neutral Relations [2000], Intro)
     A reaction: The point of Fine's paper is that there are many relations for which this model seems to fail.
The 'positionalist' view of relations says the number of places is fixed, but not the order [Fine,K]
     Full Idea: The 'positionalist' view of relations is that each relation is taken to be endowed with a given number of argument places, or positions, in no specified order. [...The argument-places are specific entities, such as 'lover' and 'beloved']
     From: Kit Fine (Neutral Relations [2000], Intro)
     A reaction: Fine offers this as an alternative to the 'standard' view of relations, in which the order of the objects matters. He then adds, and favours, the 'anti-positionalist' view, where there are not even a fixed number of places.
A block on top of another contains one relation, not both 'on top of' and 'beneath' [Fine,K]
     Full Idea: If block a is on block b, it is hard to see how this state of affairs might consist of both 'on top of' and 'beneath'. Surely if the state is a genuine relational complex, there must be a single relation for these relata?
     From: Kit Fine (Neutral Relations [2000], 1)
     A reaction: He has already shown that if such relations imply their converses, then that gives you two separate relations. He goes on to observe that you cannot pick one of the two as correct, because of symmetry. He later offers the 'vertical placement' relation.
Language imposes a direction on a road which is not really part of the road [Fine,K]
     Full Idea: Roads in the directional sense (A-to-B or B-to-A) are merely roads in the adirectional sense up which a direction has been imposed.
     From: Kit Fine (Neutral Relations [2000], 1)
     A reaction: This is Fine's linguistic objection to the standard view of relations. It is undeniable that language imposes an order where it may not exist ('Bob and Jane play tennis'), and this fact is very significant in discussing relations.
Explain biased relations as orderings of the unbiased, or the unbiased as permutation classes of the biased? [Fine,K]
     Full Idea: A 'biased' relation can be taken to be the result of imposing ordering on the argument-places of an unbiased relation, ..or we can take an unbiased relation to be a 'permutation class' of biased relations. This is a familiar metaphysic predicament.
     From: Kit Fine (Neutral Relations [2000], 3)
     A reaction: 'Biased' relations such as 'on top of' have an ordering to their places, but 'unbiased' relations such as 'vertical placement' do not. This is a nice question in the metaphysics of grounding relations between key concepts.