15 ideas
11178 | The essence or definition of an essence involves either a class of properties or a class of propositions [Fine,K] |
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] |
10121 | Contradiction is not a sign of falsity, nor lack of contradiction a sign of truth [Pascal] |
11175 | Logical concepts rest on certain inferences, not on facts about implications [Fine,K] |
11176 | The property of Property Abstraction says any suitable condition must imply a property [Fine,K] |
11174 | A logical truth is true in virtue of the nature of the logical concepts [Fine,K] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
11177 | Can the essence of an object circularly involve itself, or involve another object? [Fine,K] |
11173 | Being a man is a consequence of his essence, not constitutive of it [Fine,K] |
11179 | If there are alternative definitions, then we have three possibilities for essence [Fine,K] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |