20 ideas
13838 | A decent modern definition should always imply a semantics [Hacking] |
13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [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] |
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] |
19405 | Substances are in harmony, because they each express the one reality in themselves [Leibniz] |
6230 | If the soul were a tabula rasa, with no innate ideas, there could be no moral goodness or justice [Cudworth] |
6228 | Senses cannot judge one another, so what judges senses cannot be a sense, but must be superior [Cudworth] |
6229 | Sense is fixed in the material form, and so can't grasp abstract universals [Cudworth] |
6227 | Keeping promises and contracts is an obligation of natural justice [Cudworth] |
6225 | Obligation to obey all positive laws is older than all laws [Cudworth] |
6224 | An omnipotent will cannot make two things equal or alike if they aren't [Cudworth] |
6223 | If the will and pleasure of God controls justice, then anything wicked or unjust would become good if God commanded it [Cudworth] |
6226 | The requirement that God must be obeyed must precede any authority of God's commands [Cudworth] |