26 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] |
17486 | Supervenience is simply modally robust property co-variance [Hendry] |
17481 | Nuclear charge (plus laws) explains electron structure and spectrum, but not vice versa [Hendry] |
6012 | We must choose in which of the virtues we wish to excel [Panaetius] |
6013 | Panaetius said we should live according to our natural starting-points [Panaetius, by Asmis] |
6014 | Panaetius identified courage with great-mindedness, preferring civic courage to military [Panaetius, by Asmis] |
17478 | Maybe two kinds are the same if there is no change of entropy on isothermal mixing [Hendry] |
17484 | Maybe the nature of water is macroscopic, and not in the microstructure [Hendry] |
17479 | The nature of an element must survive chemical change, so it is the nucleus, not the electrons [Hendry] |
17485 | Maybe water is the smallest part of it that still counts as water (which is H2O molecules) [Hendry] |
17482 | Compounds can differ with the same collection of atoms, so structure matters too [Hendry] |
17483 | Water continuously changes, with new groupings of molecules [Hendry] |
17476 | Elements survive chemical change, and are tracked to explain direction and properties [Hendry] |
17477 | Defining elements by atomic number allowed atoms of an element to have different masses [Hendry] |
17480 | Generally it is nuclear charge (not nuclear mass) which determines behaviour [Hendry] |
5888 | Souls are born, since they are sensitive and inherited, so they must perish [Panaetius, by Cicero] |