16 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] |
| 6417 | In 1921 Russell abandoned sense-data, and the gap between sensation and object [Russell, by Grayling] |
| 6474 | Seeing is not in itself knowledge, but is separate from what is seen, such as a patch of colour [Russell] |
| 6476 | We cannot assume that the subject actually exists, so we cannot distinguish sensations from sense-data [Russell] |
| 2792 | It is possible the world came into existence five minutes ago, complete with false memories [Russell] |
| 22326 | Knowledge needs more than a sensitive response; the response must also be appropriate [Russell] |
| 6475 | In perception, the self is just a logical fiction demanded by grammar [Russell] |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |