34 ideas
1708 | In "Callias is just/not just/unjust", which of these are contraries? [Aristotle] |
13886 | Later Frege held that definitions must fix a function's value for every possible argument [Frege, by Wright,C] |
9845 | We can't define a word by defining an expression containing it, as the remaining parts are a problem [Frege] |
10019 | Only what is logically complex can be defined; what is simple must be pointed to [Frege] |
1703 | It is necessary that either a sea-fight occurs tomorrow or it doesn't, though neither option is in itself necessary [Aristotle] |
1704 | Statements are true according to how things actually are [Aristotle] |
22272 | Aristotle's later logic had to treat 'Socrates' as 'everything that is Socrates' [Potter on Aristotle] |
9405 | Square of Opposition: not both true, or not both false; one-way implication; opposite truth-values [Aristotle] |
9730 | Modal Square 3: □P and ¬◊¬P are 'contradictories' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
9728 | Modal Square 1: □P and ¬◊¬P are 'contraries' of □¬P and ¬◊P [Aristotle, by Fitting/Mendelsohn] |
9729 | Modal Square 2: ¬□¬P and ◊P are 'subcontraries' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
9731 | Modal Square 4: □¬P and ¬◊P are 'contradictories' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
9732 | Modal Square 5: □P and ¬◊¬P are 'subalternatives' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
9733 | Modal Square 6: □¬P and ¬◊P are 'subalternatives' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
21593 | In talking of future sea-fights, Aristotle rejects bivalence [Aristotle, by Williamson] |
1701 | A prayer is a sentence which is neither true nor false [Aristotle] |
9886 | Cardinals say how many, and reals give measurements compared to a unit quantity [Frege] |
9889 | Real numbers are ratios of quantities [Frege, by Dummett] |
10553 | A number is a class of classes of the same cardinality [Frege, by Dummett] |
10020 | Frege's biggest error is in not accounting for the senses of number terms [Hodes on Frege] |
9887 | Formalism misunderstands applications, metatheory, and infinity [Frege, by Dummett] |
8751 | Only applicability raises arithmetic from a game to a science [Frege] |
1706 | Non-existent things aren't made to exist by thought, because their non-existence is part of the thought [Aristotle] |
1707 | Maybe necessity and non-necessity are the first principles of ontology [Aristotle] |
9891 | The first demand of logic is of a sharp boundary [Frege] |
9890 | The modern account of real numbers detaches a ratio from its geometrical origins [Frege] |
11846 | If we abstract the difference between two houses, they don't become the same house [Frege] |
2337 | For Aristotle meaning and reference are linked to concepts [Aristotle, by Putnam] |
13763 | Spoken sounds vary between people, but are signs of affections of soul, which are the same for all [Aristotle] |
1705 | It doesn't have to be the case that in opposed views one is true and the other false [Aristotle] |
22331 | Moral statements are imperatives rather than the avowals of emotion - but universalisable [Hare, by Glock] |
22484 | Universalised prescriptivism could be seen as implying utilitarianism [Hare, by Foot] |
6449 | The categorical imperative leads to utilitarianism [Hare, by Nagel] |
1702 | Things may be necessary once they occur, but not be unconditionally necessary [Aristotle] |