14 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] |
| 14361 | Lewis says indicative conditionals are truth-functional [Lewis, by Jackson] |
| 8434 | In good counterfactuals the consequent holds in world like ours except that the antecedent is true [Lewis, by Horwich] |
| 9329 | Justification is coherence with a background system; if irrefutable, it is knowledge [Lehrer] |
| 9330 | Generalization seems to be more fundamental to minds than spotting similarities [Lehrer] |
| 9328 | All conscious states can be immediately known when attention is directed to them [Lehrer] |
| 9419 | A law of nature is a general axiom of the deductive system that is best for simplicity and strength [Lewis] |