26 ideas
13838 | A decent modern definition should always imply a semantics [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] |
13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
17751 | Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki] |
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] |
18680 | To avoid misunderstandings supervenience is often expressed negatively: no A-change without B-change [Orsi] |
18684 | Rather than requiring an action, a reason may 'entice' us, or be 'eligible', or 'justify' it [Orsi] |
18666 | Value-maker concepts (such as courageous or elegant) simultaneously describe and evaluate [Orsi] |
18685 | Final value is favoured for its own sake, and personal value for someone's sake [Orsi] |
18667 | The '-able' concepts (like enviable) say this thing deserves a particular response [Orsi] |
18679 | Things are only valuable if something makes it valuable, and we can ask for the reason [Orsi] |
18682 | A complex value is not just the sum of the values of the parts [Orsi] |
18683 | Trichotomy Thesis: comparable values must be better, worse or the same [Orsi] |
18686 | The Fitting Attitude view says values are fitting or reasonable, and values are just byproducts [Orsi] |
18672 | Values from reasons has the 'wrong kind of reason' problem - admiration arising from fear [Orsi] |
18677 | A thing may have final value, which is still derived from other values, or from relations [Orsi] |
18669 | Values can be normative in the Fitting Attitude account, where 'good' means fitting favouring [Orsi] |
18670 | The Buck-Passing view of normative values says other properties are reasons for the value [Orsi] |
18668 | Truths about value entail normative truths about actions or attitudes [Orsi] |