4 ideas
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| Full Idea: C.I.Lewis constructed five axiomatic systems of modal logic, and named them S1 to S5. It turns out that the simplest of the logics based on possible worlds is the same as Lewis's S5. | |
| From: report of C.I. Lewis (works [1935]) by Rod Girle - Modal Logics and Philosophy 2.1 | |
| A reaction: Nathan Salmon ('Reference and Essence' 2nd ed) claims (on p.xvii) that "the correct modal logic is weaker than S5 and weaker even than S4". Which is the greater virtue, simplicity or weakness? |
| 11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
| Full Idea: C.I.Lewis's S4 system develops a sense of necessity as 'provability' in some fairly informal sense. | |
| From: report of C.I. Lewis (works [1935]) by Stephen Read - Thinking About Logic Ch. 4 |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 5064 | Rights are moral significance, or liberty, or right not to be restrained, or entitlement [Mawson] |
| Full Idea: A 'right' can mean 'x counts morally', or 'x is permitted to do this' (liberty), or 'x can't be stopped from doing this' (negative right), or 'someone should provide this for x'. | |
| From: Tim Mawson (Animal Rights talk [2003]), quoted by PG - lecture notes | |
| A reaction: A useful analysis. It is a useful preliminary to considering whether any of these are natural rights. Personally I am sympathetic to that concept. You cannot deny a person's right to self-defence, even when you are sitting on them. Persons have rights. |