20 ideas
19115 | You can 'rebut' an argument's conclusion, or 'undercut' its premises [Antonelli] |
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
19119 | We infer that other objects are like some exceptional object, if they share some of its properties [Antonelli] |
19111 | Reasoning may be defeated by new premises, or by finding out more about the given ones [Antonelli] |
19114 | Should we accept Floating Conclusions, derived from two arguments in conflict? [Antonelli] |
19113 | Weakest Link Principle: prefer the argument whose weakest link is the stronger [Antonelli] |
19116 | Non-monotonic core: Reflexivity, Cut, Cautious Monotonicity, Left Logical Equivalence, Right Weakening [Antonelli] |
19117 | We can rank a formula by the level of surprise if it were to hold [Antonelli] |
19118 | People don't actually use classical logic, but may actually use non-monotonic logic [Antonelli] |
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] |
19110 | In classical logic the relation |= has Monotony built into its definition [Antonelli] |
19112 | Cautious Monotony ignores proved additions; Rational Monotony fails if the addition's negation is proved [Antonelli] |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
16736 | Explanation is generally to deduce it from something better known, which comes in degrees [Boyle] |
16737 | The best explanations get down to primary basics, but others go less deep [Boyle] |