4 ideas
9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
9463 | Classical logic is bivalent, has excluded middle, and only quantifies over existent objects [Jacquette] |
18948 | There is an object for every set of properties (some of which exist, and others don't) [Parsons,T, by Sawyer] |
9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |