19 ideas
12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |
19544 | Closure says if you know P, and also know P implies Q, then you must know Q [Dretske] |
19545 | We needn't regret the implications of our regrets; regretting drinking too much implies the past is real [Dretske] |
19546 | Knowing by visual perception is not the same as knowing by implication [Dretske] |
19547 | Reasons for believing P may not transmit to its implication, Q [Dretske] |
19548 | The only way to preserve our homely truths is to abandon closure [Dretske] |
19549 | P may imply Q, but evidence for P doesn't imply evidence for Q, so closure fails [Dretske] |
19550 | We know past events by memory, but we don't know the past is real (an implication) by memory [Dretske] |
22200 | If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle] |