29 ideas
1922 | Spiritual qualities only become advantageous with the growth of wisdom [Plato] |
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] |
11259 | How can you seek knowledge of something if you don't know it? [Plato] |
20219 | True opinions only become really valuable when they are tied down by reasons [Plato] |
5985 | Seeking and learning are just recollection [Plato] |
5986 | The slave boy learns geometry from questioning, not teaching, so it is recollection [Plato] |
1923 | As a guide to action, true opinion is as good as knowledge [Plato] |
1919 | You don't need to learn what you know, and how do you seek for what you don't know? [Plato] |
1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
1927 | It seems that virtue is neither natural nor taught, but is a divine gift [Plato] |
1913 | Is virtue taught, or achieved by practice, or a natural aptitude, or what? [Plato] |
1921 | If virtue is a type of knowledge then it ought to be taught [Plato] |
1916 | Even if virtues are many and various, they must have something in common to make them virtues [Plato] |
1918 | How can you know part of virtue without knowing the whole? [Plato] |