12 ideas
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] |
20752 | For man, being is not what he is, but what he is going to be [Ortega y Gassett] |
9212 | Possible states of affairs are not propositions; a proposition can't be a state of affairs! [Fine,K] |
9213 | The actual world is a possible world, so we can't define possible worlds as 'what might have been' [Fine,K] |
20756 | Instead of having a nature, man only has a history [Ortega y Gassett] |