18 ideas
10163 | Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman] |
10760 | With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg] |
16189 | The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen] |
15132 | The Barcan formulas fail in models with varying domains [Kripke, by Williamson] |
13430 | Infinity: there is an infinity of distinguishable individuals [Ramsey] |
13428 | Reducibility: to every non-elementary function there is an equivalent elementary function [Ramsey] |
13427 | Either 'a = b' vacuously names the same thing, or absurdly names different things [Ramsey] |
13334 | Contradictions are either purely logical or mathematical, or they involved thought and language [Ramsey] |
13426 | Formalists neglect content, but the logicists have focused on generalizations, and neglected form [Ramsey] |
13425 | Formalism is hopeless, because it focuses on propositions and ignores concepts [Ramsey] |
22328 | I just confront the evidence, and let it act on me [Ramsey] |
21515 | Incoherence may be more important for enquiry than coherence [Olsson] |
21514 | Coherence is the capacity to answer objections [Olsson] |
21496 | Mere agreement of testimonies is not enough to make truth very likely [Olsson] |
21499 | Coherence is only needed if the information sources are not fully reliable [Olsson] |
21502 | A purely coherent theory cannot be true of the world without some contact with the world [Olsson] |
21512 | Extending a system makes it less probable, so extending coherence can't make it more probable [Olsson] |
22325 | A belief is knowledge if it is true, certain and obtained by a reliable process [Ramsey] |