12 ideas
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
21375 | Reason can be vicious, and great crimes have to be rational [Schopenhauer] |
21379 | Man's three basic ethical incentives are egoism, malice and compassion [Schopenhauer] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
21376 | Philosophy treats animals as exploitable things, ignoring the significance of their lives [Schopenhauer] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |