33 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] |
| 15435 | If you think universals are immanent, you must believe them to be sparse, and not every related predicate [Lewis] |
| 15451 | I assume there could be natural properties that are not instantiated in our world [Lewis] |
| 15433 | Tropes are particular properties, which cannot recur, but can be exact duplicates [Lewis] |
| 15436 | Universals are meant to give an account of resemblance [Lewis] |
| 15438 | We can add a primitive natural/unnatural distinction to class nominalism [Lewis] |
| 15448 | The 'magical' view of structural universals says they are atoms, even though they have parts [Lewis] |
| 15449 | If 'methane' is an atomic structural universal, it has nothing to connect it to its carbon universals [Lewis] |
| 15439 | The 'pictorial' view of structural universals says they are wholes made of universals as parts [Lewis] |
| 15441 | The structural universal 'methane' needs the universal 'hydrogen' four times over [Lewis] |
| 15445 | Butane and Isobutane have the same atoms, but different structures [Lewis] |
| 15434 | Structural universals have a necessary connection to the universals forming its parts [Lewis] |
| 15437 | We can't get rid of structural universals if there are no simple universals [Lewis] |
| 15446 | Composition is not just making new things from old; there are too many counterexamples [Lewis] |
| 15440 | A whole is distinct from its parts, but is not a further addition in ontology [Lewis] |
| 15444 | Different things (a toy house and toy car) can be made of the same parts at different times [Lewis] |
| 15450 | Maybe abstraction is just mereological subtraction [Lewis] |
| 15443 | Mathematicians abstract by equivalence classes, but that doesn't turn a many into one [Lewis] |
| 22971 | In moving from capitalism to communism a revolutionary dictatorship of the proletariat is needed [Marx] |
| 22000 | From each according to his ability, to each according to his need [Marx] |
| 22969 | People who only have their labour power are the slaves of those permitting them to work [Marx] |
| 22970 | Freedom is making the state subordinate to its society [Marx] |
| 22972 | Bourgeois 'freedom of conscience' just tolerates all sorts of religious intolerance [Marx] |