18 ideas
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| 19355 | The soul doesn't understand many of its own actions, if perceptions are confused and desires buried [Leibniz] |
| 19350 | We should say that body is mechanism and soul is immaterial, asserting their independence [Leibniz] |
| 23395 | Mohists desire wealth, population and social order as the best consequences [Mozi, by Norden] |
| 23394 | If people regarded other states as they did their own, they would never attack them [Mozi] |
| 23396 | Mozi condemns partiality, which is the cause of all the great harms in the world [Mozi] |
| 23397 | Those who are against impartiality still prefer impartial protectors [Mozi] |
| 19356 | Minds unconsciously count vibration beats in music, and enjoy it when they coincide [Leibniz] |