18 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] |
10180 | Mathematicians do not study objects, but relations between objects [Poincaré] |
17771 | How we evaluate evidence depends on our background beliefs [Bayne] |
17770 | Clifford's dictum seems to block our beliefs in morality, politics and philosophy [Bayne] |
17766 | Physicalism correlates brain and mind, explains causation by thought, and makes nature continuous [Bayne] |
17768 | Perception reveals what animals think, but humans can disengage thought from perception [Bayne] |
17769 | Some people centre space on themselves; others centre space on the earth [Bayne] |
17767 | The alternative to a language of thought is map-like or diagram-like thought [Bayne] |