22 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] |
18890 | Putnam smuggles essentialism about liquids into his proof that water must be H2O [Salmon,N on Putnam] |
7705 | The Twin Earth theory suggests that intentionality is independent of qualia [Jacquette on Putnam] |
4099 | If Twins talking about 'water' and 'XYZ' have different thoughts but identical heads, then thoughts aren't in the head [Putnam, by Crane] |
12026 | We say ice and steam are different forms of water, but not that they are different forms of H2O [Forbes,G on Putnam] |
3208 | Does 'water' mean a particular substance that was 'dubbed'? [Putnam, by Rey] |
3893 | Often reference determines sense, and not (as Frege thought) vice versa [Putnam, by Scruton] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
11191 | The hidden structure of a natural kind determines membership in all possible worlds [Putnam] |
11192 | If causes are the essence of diseases, then disease is an example of a relational essence [Putnam, by Williams,NE] |
11190 | Archimedes meant by 'gold' the hidden structure or essence of the stuff [Putnam] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |