12 ideas
| 9184 | We can't presume that all interesting concepts can be analysed [Williamson] |
| Full Idea: We have no prior reason to suppose that philosophically significant concepts have interesting analyses into necessary and sufficient conditions. | |
| From: Timothy Williamson (Review of Bob Hale's 'Abstract Objects' [1988]) | |
| A reaction: We might think that they are either analysable or primitive, and that failure of analysis invites us to take a concept as primitive. But maybe God can analyse it and we can't. |
| 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) |
| 9183 | Platonism claims that some true assertions have singular terms denoting abstractions, so abstractions exist [Williamson] |
| Full Idea: The Fregean argument for platonism is that some true assertions contain singular terms which denote abstract objects if they denote anything; since the assertions are true, the singular terms denote. | |
| From: Timothy Williamson (Review of Bob Hale's 'Abstract Objects' [1988]) | |
| A reaction: I am perplexed that anyone would rest their view of reality on such an argument. The obvious comparison would be with true remarks about blatantly fictional characters, or blatantly invented concepts such as 'checkmate'. |
| 6012 | We must choose in which of the virtues we wish to excel [Panaetius] |
| Full Idea: Humans have four roles in life, of which the fourth involves choices, of career, and of the virtue in which one wishes to excel. | |
| From: Panaetius (fragments/reports [c.145 BCE]), quoted by Elizabeth Asmis - Panaetius | |
| A reaction: Panaetius strikes me as exceptionally wise. A big gap in Aristotle is the fact that we cannot excel in all virtues, and that therefore some choice is required. By what criteria? We have the Gauguin problem (excel in one, disgraceful in the others). |
| 6013 | Panaetius said we should live according to our natural starting-points [Panaetius, by Asmis] |
| Full Idea: Panaetius reformulated the Stoic goal as living in accordance with the starting-points given to us by nature. | |
| From: report of Panaetius (fragments/reports [c.145 BCE]) by Elizabeth Asmis - Panaetius | |
| A reaction: This sounds remarkably like the substitution of meritocratic equality of opportunity for communistic actual equality. In other words, it doesn't sound very Stoic. 'Live according to nature' implies more restraint than this ambitious version. |
| 6014 | Panaetius identified courage with great-mindedness, preferring civic courage to military [Panaetius, by Asmis] |
| Full Idea: Panaetius recast the virtue of courage as 'greatmindedness' (Aristotle's paramount virtue), he demoted military valour and gave priority to courage displayed in civic life. | |
| From: report of Panaetius (fragments/reports [c.145 BCE]) by Elizabeth Asmis - Panaetius | |
| A reaction: I find this very appealing, as I am increasingly horrified by our denigration of the people who implement our democracy for us. We urgently need to get back to the Greek idea of civic virtue, and this idea of Panaetius should be widely promulgated. |
| 5888 | Souls are born, since they are sensitive and inherited, so they must perish [Panaetius, by Cicero] |
| Full Idea: Panaetius says that whatever is born must perish, and souls are clearly born, as shown by the resemblance of children to their parents in disposition as well as body; also, anything sensible of pain is susceptible to sickness, and hence perishes. | |
| From: report of Panaetius (fragments/reports [c.145 BCE]) by M. Tullius Cicero - Tusculan Disputations I.xxxii | |
| A reaction: These seem to be rather good arguments. If we actually observe what someone's soul is like (through character) it seems rooted in a family and culture, and it certainly seems susceptible to disease. An empirical approach. |