21 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] |
14288 | 'If A,B' affirms that A⊃B, and also that this wouldn't change if A were certain [Jackson, by Edgington] |
13769 | Conditionals are truth-functional, but should only be asserted when they are confident [Jackson, by Edgington] |
7590 | Consequentialism emphasises value rather than obligation in morality [Scruton] |
7589 | Altruism is either emotional (where your interests are mine) or moral (where they are reasons for me) [Scruton] |
7595 | The idea of a right seems fairly basic; justice may be the disposition to accord rights to people [Scruton] |
7588 | Allegiance is fundamental to the conservative view of society [Scruton] |
7594 | Democrats are committed to a belief and to its opposite, if the majority prefer the latter [Scruton] |
7593 | Liberals focus on universal human freedom, natural rights, and tolerance [Scruton, by PG] |
7592 | For positivists law is a matter of form, for naturalists it is a matter of content [Scruton] |
7587 | The issue of abortion seems insoluble, because there is nothing with which to compare it [Scruton] |