9 ideas
2572 | Logical truth seems much less likely to 'correspond to the facts' than factual truth does [Haack] |
Full Idea: It is surely less plausible to suppose that logical truth consists in correspondence to the facts than that 'factual' truth does. | |
From: Susan Haack (Philosophy of Logics [1978], 7.6) |
2570 | The same sentence could be true in one language and meaningless in another, so truth is language-relative [Haack] |
Full Idea: The definition of truth will have to be, Tarski argues, relative to a language, for one and the same sentence may be true in one language, and false or meaningless in another. | |
From: Susan Haack (Philosophy of Logics [1978], 7.5) |
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) |
14349 | If there are no finks or antidotes at the fundamental level, the laws can't be ceteris paribus [Burge, by Corry] |
Full Idea: Bird argues that there are no finks at the fundamental level, and unlikely to be any antidotes. It then follows that laws at the fundamental level will all be strict - not ceteris paribus - laws. | |
From: report of Tyler Burge (Intellectual Norms and Foundations of Mind [1986]) by Richard Corry - Dispositional Essentialism Grounds Laws of Nature? 3 | |
A reaction: [Bird's main target is Nancy Cartwright 1999] This is a nice line of argument. Isn't part of the ceteris paribus problem that two fundamental laws might interfere with one another? |