16 ideas
15527 | Defining terms either enables elimination, or shows that they don't require elimination [Lewis] |
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
15530 | A logically determinate name names the same thing in every possible world [Lewis] |
15531 | The Ramsey sentence of a theory says that it has at least one realisation [Lewis] |
15528 | A Ramsey sentence just asserts that a theory can be realised, without saying by what [Lewis] |
15526 | There is a method for defining new scientific terms just using the terms we already understand [Lewis] |
15529 | It is better to have one realisation of a theory than many - but it may not always be possible [Lewis] |
16713 | Philosophers are the forefathers of heretics [Tertullian] |
6610 | I believe because it is absurd [Tertullian] |