4 ideas
7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
18810 | Aristotle's proofs give understanding, so it can't be otherwise, so consequence is necessary [Smiley, by Rumfitt] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |