25 ideas
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] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
21332 | We don't get a love of 'order' from nature - which is thoroughly chaotic [Mill] |
21333 | Evil comes from good just as often as good comes from evil [Mill] |
21335 | Belief that an afterlife is required for justice is an admission that this life is very unjust [Mill] |
21334 | No necessity ties an omnipotent Creator, so he evidently wills human misery [Mill] |
21329 | Nature dispenses cruelty with no concern for either mercy or justice [Mill] |
21328 | Killing is a human crime, but nature kills everyone, and often with great tortures [Mill] |
21330 | Nature makes childbirth a miserable experience, often leading to the death of the mother [Mill] |
21331 | Hurricanes, locusts, floods and blight can starve a million people to death [Mill] |