29 ideas
8820 | Rules of reasoning precede the concept of truth, and they are what characterize it [Pollock] |
8819 | We need the concept of truth for defeasible reasoning [Pollock] |
10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
10763 | Completeness and compactness together give axiomatizability [Tharp] |
10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
8822 | Statements about necessities need not be necessarily true [Pollock] |
8818 | Defeasible reasoning requires us to be able to think about our thoughts [Pollock] |
8811 | What we want to know is - when is it all right to believe something? [Pollock] |
8817 | Logical entailments are not always reasons for beliefs, because they may be irrelevant [Pollock] |
8814 | Epistemic norms are internalised procedural rules for reasoning [Pollock] |
8823 | Reasons are always for beliefs, but a perceptual state is a reason without itself being a belief [Pollock] |
8813 | If we have to appeal explicitly to epistemic norms, that will produce an infinite regress [Pollock] |
8812 | Norm Externalism says norms must be internal, but their selection is partly external [Pollock] |
8816 | Externalists tend to take a third-person point of view of epistemology [Pollock] |
8815 | Belief externalism is false, because external considerations cannot be internalized for actual use [Pollock] |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |