14 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) |
15473 | How does anything get outside itself? [Fodor, by Martin,CB] |
Full Idea: Fodor asks the stirring and basic question 'How does anything get outside itself?' | |
From: report of Jerry A. Fodor (works [1986]) by C.B. Martin - The Mind in Nature 03.6 | |
A reaction: Is this one of those misconceived questions, like major issues concerning 'what's it like to be?' In what sense am I outside myself? Is a mind any more mysterious than a shadow? |
2981 | Is intentionality outwardly folk psychology, inwardly mentalese? [Lyons on Fodor] |
Full Idea: For Fodor the intentionality of the propositional-attitude vocabulary of our folk psychology is the outward expression of the inward intentionality of the language of the brain. | |
From: comment on Jerry A. Fodor (works [1986]) by William Lyons - Approaches to Intentionality p.39 | |
A reaction: I would be very cautious about this. Folk psychology works, so it must have a genuine basis in how brains work, but it breaks down in unusual situations, and might even be a total (successful) fiction. |
22371 | Determinism threatens free will if actions can be causally traced to external factors [Foot] |
Full Idea: The determinism which worries the defender of free will is that if human action is subject to a universal law of causation, there will be for any action a set of sufficient conditions which can be traced back to factors outside the control of the agent. | |
From: Philippa Foot (Free Will as Involving Determinism [1957], p.63) | |
A reaction: She draws on Russell for this, but neither of them mention whether the causation is physical. Free will seems to imply non-physical causation. |
2985 | Are beliefs brains states, but picked out at a "higher level"? [Lyons on Fodor] |
Full Idea: Fodor holds that beliefs are brain states or processes, but picked out at a 'higher' or 'special science' level. | |
From: comment on Jerry A. Fodor (works [1986]) by William Lyons - Approaches to Intentionality p.82 | |
A reaction: I don't think you can argue with this. Levels of physical description exist (e.g. pure physics tells you nothing about the weather), and I think 'process' is the best word for the mind (Idea 4931). |
3135 | Is thought a syntactic computation using representations? [Fodor, by Rey] |
Full Idea: The modest mentalism of the Computational/Representational Theory of Thought (CRTT), associated with Fodor, says mental processes are computational, defined over syntactically specified entities, and these entities represent the world (are also semantic). | |
From: report of Jerry A. Fodor (works [1986]) by Georges Rey - Contemporary Philosophy of Mind Int.3 | |
A reaction: This seems to imply that if you built a machine that did all these things, it would become conscious, which sounds unlikely. Do footprints 'represent' feet, or does representation need prior consciousness? |
2983 | Maybe narrow content is physical, broad content less so [Lyons on Fodor] |
Full Idea: Fodor is concerned with producing a realist and physicalist account of 'narrow content' (i.e. wholly in-the-head content). | |
From: comment on Jerry A. Fodor (works [1986]) by William Lyons - Approaches to Intentionality p.54 | |
A reaction: The emergence of 'wide' content has rather shaken Fodor's game plan. We can say "Oh dear, I thought I was referring to H2O", so there must be at least some narrow aspect to reference. |
22372 | Not all actions need motives, but it is irrational to perform troublesome actions with no motive [Foot] |
Full Idea: We do not expect that everything a rational man does should be done with a motive, ...but we do expect a man to have a motive for many things that he does, and would count anyone who constantly performed troublesome actions without a motive as irrational. | |
From: Philippa Foot (Free Will as Involving Determinism [1957], p.66) | |
A reaction: Interestng, because the assessment of whether someone is 'rational' therefore needs a criterion for when a motive seems required and when not. 'Significant' actions need a motive? |
22373 | People can act out of vanity without being vain, or even vain about this kind of thing [Foot] |
Full Idea: It makes sense to say that a man acts out of vanity on a particular occasion although he is not in general vain, or even vain about this kind of thing. | |
From: Philippa Foot (Free Will as Involving Determinism [1957], p.69) | |
A reaction: Aristotle tells us that virtues and vices are habits, and also have an intellectual component, implying that the person believes in that sort of behaviour. Anyone can have 'a little moment of vanity'. |