12 ideas
| 18261 | A simplification which is complete constitutes a definition [Kant] |
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| 22275 | Logic gives us the necessary rules which show us how we ought to think [Kant] |
| 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] |
| 19405 | Substances are in harmony, because they each express the one reality in themselves [Leibniz] |
| 18260 | If we knew what we know, we would be astonished [Kant] |