13 ideas
17884 | 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) |
17893 | '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) |
17894 | 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) |
17890 | 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] |
17887 | 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. |
17891 | 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) |
20076 | An intending is a judgement that the action is desirable [Davidson] |
Full Idea: We can identify an intentional action ...with an all-out conditional judgement that the action is desirable. ...In the case of pure intending, I now suggest that the intention simply is an all-out judgement. | |
From: Donald Davidson (Intending [1978], p.99), quoted by Rowland Stout - Action 8 'Davidson's' | |
A reaction: 'Pure' intending seems to be what Stout calls 'prior' intending, which is clearer. This still strikes me as obviously false. I judge that it is desirable that I make a cup of coffee, but secretly I'm hoping someone else will make it for me. |
20024 | Davidson gave up reductive accounts of intention, and said it was a primitive [Davidson, by Wilson/Schpall] |
Full Idea: Later Davidson dropped his reductive treatment of intentions (in terms of 'pro-attitudes' and other beliefs), and accepted that intentions are irreducible, and distinct from pro-attitudes. | |
From: report of Donald Davidson (Intending [1978]) by Wilson,G/Schpall,S - Action 2 | |
A reaction: Only a philosopher would say that intentions cannot be reduced to something else. Since I have a very physicalist view of the mind, I incline to reduce them to powers and dispositions of physical matter. |
22445 | Morality shows murder is wrong, but not what counts as a murder [Foot] |
Full Idea: While one can determine from the concept of morality that there is an objection to murder one cannot determine completely what will count as murder. | |
From: Philippa Foot (Morality and Art [1972], p.7) | |
A reaction: She then refers to abortion, but there are military and criminal problem cases, and killings by neglect or side effect. |
22444 | A moral system must deal with the dangers and benefits of life [Foot] |
Full Idea: A moral system seems necessarily to be one aimed at removing particular dangers and securing certain benefits. | |
From: Philippa Foot (Morality and Art [1972], p.6) | |
A reaction: I thoroughly approve of this approach to morality, which anchors it in real life, rather than in ideals or principles of reason. |
22447 | Saying something 'just is' right or wrong creates an illusion of fact and objectivity [Foot] |
Full Idea: When we say that something 'just is' right or wrong we want to give the impression of some kind of fact or authority standing behind our words, ...maintaining the trappings of objectivity though the substance is not there. | |
From: Philippa Foot (Morality and Art [1972], p.9) | |
A reaction: Foot favours the idea that such a claim must depend on reasons, and that the reasons arise out of actual living. She's right. |
22448 | We sometimes just use the word 'should' to impose a rule of conduct on someone [Foot] |
Full Idea: It would be more honest to recognise that the 'should' of moral judgement is sometimes merely an instrument by which we (for our own very good reasons) try to impose a rule of conduct even on the uncaring man? | |
From: Philippa Foot (Morality and Art [1972], p.18) | |
A reaction: This is a good example, I think, of the ordinary language tradition that Foot grew up in. We load a word like 'should' with a mystical power, but the situations in which it is actually used bring us back down to earth. |
22446 | In the case of something lacking independence, calling it a human being is a matter of choice [Foot] |
Full Idea: In the problem of abortion there is a genuine choice as to whether or not to count as a human being, with the rights of a human being, what would become a human being but is not yet capable of independent life. | |
From: Philippa Foot (Morality and Art [1972], p.7) | |
A reaction: There must be some basis for the choice. We can't call a dead person a human being. Choosing to call a tiny zygote a human being seems very implausible. Pre-viability strikes me as implausible. |